To explore the role of biofilm formation on the corrosion of marine concrete structures, we investigated the attachment of biofilm on mortar surfaces in simulated seawater and the influence of biofilm on the microstru...To explore the role of biofilm formation on the corrosion of marine concrete structures, we investigated the attachment of biofilm on mortar surfaces in simulated seawater and the influence of biofilm on the microstructure of mortar surfaces. The results show that the evolution of biofilm on mortar surfaces in simulated seawater is closely related to the corrosion suffered by the mortar, and the process of biofilm attachment and shedding is continuous and cyclical. It is found that the specimens in the absence of biofilm attachment are more severely eroded internally by the corrosive medium in simulated seawater than those in the presence of biofilm attachment. For the specimens without biofilm attachment, after 60 days, gypsum forms,and after 120 days, the number of pores in the mortar is reduced. In contrast, for the specimens in the presence of biofilm attachment, gypsum could only be detected after 90 days, and fewer pores are filled. Therefore, the formation of biofilm could delay the invasion of the corrosive medium into the interior of mortar during the evolution of biofilm on mortar surfaces, mitigating the corrosion of mortars in seawater.展开更多
In the processing of conventional marine seismic data,seawater is often assumed to have a constant velocity model.However,due to static pressure,temperature difference and other factors,random disturbances may often f...In the processing of conventional marine seismic data,seawater is often assumed to have a constant velocity model.However,due to static pressure,temperature difference and other factors,random disturbances may often frequently in seawater bodies.The impact of such disturbances on data processing results is a topic of theoretical research.Since seawater sound velocity is a difficult physical quantity to measure,there is a need for a method that can generate models conforming to seawater characteristics.This article will combine the Munk model and Perlin noise to propose a two-dimensional dynamic seawater sound velocity model generation method,a method that can generate a dynamic,continuous,random seawater sound velocity model with some regularity at large scales.Moreover,the paper discusses the influence of the inhomogeneity characteristics of seawater on wave field propagation and imaging.The results show that the seawater sound velocity model with random disturbance will have a significant influence on the wave field simulation and imaging results.展开更多
The development of efficient and robust anode materials for stable alkaline seawater electrolysis is severely limited by chlorine evolution reaction and chloride corrosion.Here,the sulfur-doped cobalt-nickel bimetalli...The development of efficient and robust anode materials for stable alkaline seawater electrolysis is severely limited by chlorine evolution reaction and chloride corrosion.Here,the sulfur-doped cobalt-nickel bimetallic phosphides(CoNiPS)are specifically designed as a pre-catalyst for navigating a surface reconstruction to fabricate the anions(PO^(3-)_(4) and SO^(2-)_(4))-decorated Co(Ni)OOH catalyst(R-CoNiPS)with exceptional durability and high activity for stable alkaline seawater oxidation(ASO).Various experiment techniques together with theoretical simulations both demonstrate that the in situ-generated PO^(3-)_(4) and SO^(2-)_(4) anions on catalyst surface can improve the oxygen evolution reaction(OER)activity,regulating and stabilizing the catalytic active species Co(Ni)OOH,as well as make a critical role in inhibiting the adsorp-tion of chloride ions and extending the service life of electrode.Therefore,this R-CoNiPS electrode exhi-bits superb OER activity toward AsO and stands out among the non-precious ASO electrocatalysts reported recently,requiring low overpotentials of 420 and 440 mV to attain large current densities of 500 and 1000 mA cm^(-2) in an alkaline natural seawater electrolyte,respectively.Particularly,the catalyst displays a negligible chloride corrosion at room temperature during ASO operation(>200 h)at 500 mA cm^(-2).This work opens up a new viewpoint for designing high-activity and durable electrocata-lystsforseawaterelectrolysis.展开更多
Seawater splitting into hydrogen,a promising technology,is seriously limited by the durability and tolerance of electrocatalysts for chlorine ions in seawater at large current densities due to chloride oxidation and c...Seawater splitting into hydrogen,a promising technology,is seriously limited by the durability and tolerance of electrocatalysts for chlorine ions in seawater at large current densities due to chloride oxidation and corrosion.Here,we present a robust and weak-nucleophilicity nickel-iron hydroxide electrocatalyst with excellent selectivity for oxygen evolution and an inert response for chlorine ion oxidation which are key and highly desired for efficient seawater electrolysis.Such a weak-nucleophilicity electrocatalyst can well match with strong-nucleophilicity OH-compared with the weak-nucleophilicity Cl^(-),resultantly,the oxidation of OH-in electrolyte can be more easily achieved relative to chlorine ion oxidation,confirmed by ethylenediaminetetraacetic acid disodium probing test.Further,no strongly corrosive hypochlorite is produced when the operating voltage reaches about 2.1 V vs.RHE,a potential that is far beyond the thermodynamic potential of chlorine ion oxidatio n.This concept and approach to reasonably designing weaknucleophilicity electrocatalysts that can greatly avoid chlorine ion oxidation under alkaline seawater environments can push forward the seawater electrolysis technology and also accelerate the development of green hydrogen technique.展开更多
Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation.Nevertheless,the direct electrolysis of seawater encounters significant challenges due to poor anodic stability cau...Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation.Nevertheless,the direct electrolysis of seawater encounters significant challenges due to poor anodic stability caused by detrimental chlorine chemistry.Herein,we present our recent discovery that the incorporation of Ce into Ni Fe layered double hydroxide nanosheet array on Ni foam(Ce-Ni Fe LDH/NF)emerges as a robust electrocatalyst for seawater oxidation.During the seawater oxidation process,CeO_(2)is generated,effectively repelling Cl^(-)and inhibiting the formation of Cl O-,resulting in a notable enhancement in the oxidation activity and stability of alkaline seawater.The prepared Ce-Ni Fe LDH/NF requires only overpotential of 390 m V to achieve the current density of 1 A cm^(-2),while maintaining long-term stability for 500 h,outperforming the performance of Ni Fe LDH/NF(430 m V,150 h)by a significant margin.This study highlights the effectiveness of a Ce-doping strategy in augmenting the activity and stability of materials based on Ni Fe LDH in seawater electrolysis for oxygen evolution.展开更多
Direct seawater electrolysis for hydrogen production has been regarded as a viable route to utilize surplus renewable energy and address the climate crisis.However,the harsh electrochemical environment of seawater,par...Direct seawater electrolysis for hydrogen production has been regarded as a viable route to utilize surplus renewable energy and address the climate crisis.However,the harsh electrochemical environment of seawater,particularly the presence of aggressive Cl^(-),has been proven to be prone to parasitic chloride ion oxidation and corrosion reactions,thus restricting seawater electrolyzer lifetime.Herein,hierarchical structure(Ni,Fe)O(OH)@NiCoS nanorod arrays(NAs)catalysts with heterointerfaces and localized oxygen vacancies were synthesized at nickel foam substrates via the combination of hydrothermal and annealing methods to boost seawater dissociation.The hiera rchical nanostructure of NiCoS NAs enhanced electrode charge transfer rate and active surface area to accelerate oxygen evolution reaction(OER)and generated sulfate gradient layers to repulsive aggressive Cl^(-).The fabricated heterostructure and vacancies of(Ni,Fe)O(OH)tuned catalyst electronic structure into an electrophilic state to enhance the binding affinity of hydroxyl intermediates and facilitate the structural transformation into amorphousγ-NiFeOOH for promoting OER.Furthermore,through operando electrochemistry techniques,we found that theγ-NiFeOOH possessing an unsaturated coordination environment and lattice-oxygen-participated OER mechanism can minimize electrode Cl^(-)corrosion enabled by stabilizing the adsorption of OH*intermediates,making it one of the best OER catalysts in the seawater medium reported to date.Consequently,these catalysts can deliver current densities of 100 and 500 mA cm-2for boosting OER at minimal overpotentials of 245and 316 mV,respectively,and thus prevent chloride ion oxidation simultaneously.Impressively,a highly stable anion exchange membrane(AEM)seawater electrolyzer based on the non-noble metal heterostructure electrodes reached a record low degradation rate under 100μV h-1at constant industrial current densities of 400 and 600 mA cm-2over 300 h,which exhibits a promising future for the nonprecious and stable AEMWE in the direct seawater electrolysis industry.展开更多
This study presents a significant contribution to the field of water quality assessment and sustainable water management practices. By evaluating the levels of total dissolved solids (TDS) in seawater intakes within A...This study presents a significant contribution to the field of water quality assessment and sustainable water management practices. By evaluating the levels of total dissolved solids (TDS) in seawater intakes within Al-Khobar desalination production system, the study addresses a crucial aspect of water treatment and environmental impact assessment. The findings provide valuable insights into the variations and trends of TDS levels across different phases of the system, highlighting the importance of monitoring and management strategies. The study provided both gravimetric total dissolved solids (TDS) and electrical conductivity (EC) measurements to analyze TDS calculation factor and evaluate measurement accuracy. Results revealed significant variations in TDS levels across the sampling locations, with phase-2 exhibiting higher levels and greater fluctuations. Phase-3 displayed similar trends but with lower TDS levels, while phase-4 showed slightly different behavior with higher average TDS levels. EC measurements demonstrated a strong correlation with TDS, providing a reliable estimation. However, additional methods such as gravimetric analysis should be employed to confirm TDS measurements. The findings contribute to understanding water quality in the Al-Khobar desalination system, aiding in monitoring, management, and decision-making processes for water treatment and environmental impact assessment. The study enhances the credibility of water quality assessments and supports sustainable water management practices.展开更多
This article examines the influence of seawater temperature and total dissolved solids (TDS) on reverse osmosis (RO) desalination in the Arabian Gulf region, with a focus on the impact of climate change. The study hig...This article examines the influence of seawater temperature and total dissolved solids (TDS) on reverse osmosis (RO) desalination in the Arabian Gulf region, with a focus on the impact of climate change. The study highlights the changes in seawater temperature and TDS levels over the years and discusses their effects on the efficiency and productivity of RO desalination plants. It emphasizes the importance of monitoring TDS levels and controlling seawater temperature to optimize water production. The article also suggests various solutions, including intensive pre-treatment, development of high-performance membranes, exploration of alternative water sources, and regulation of discharges into the Gulf, to ensure sustainable water supply in the face of rising TDS levels and seawater temperature. Further research and comprehensive monitoring are recommended to understand the implications of these findings and develop effective strategies for the management of marine resources in the Arabian Gulf.展开更多
Objective:Seawater leakage in Al-Jabal Al-Akhdar East Libya's coastal areas is one of the most biggest obstacles to farmers obtaining a highly productive crop.As a result,the experiment was conducted in a laborato...Objective:Seawater leakage in Al-Jabal Al-Akhdar East Libya's coastal areas is one of the most biggest obstacles to farmers obtaining a highly productive crop.As a result,the experiment was conducted in a laboratory to find out the impact of irrigation with seawater on the salt tolerance of Acsad Bread wheat genotypes.Method:Ten genotypes(1398,1492,1514,1522,1524,1536,1538,1544,1550,and 1562),obtained from the Arab Center for the Studies of Arid Zones and Dry Lands Acsad,were used in the study,10 seeds of each genotype with three repetitions were germinated under four seawater concentrations(10,20,30 and 40%).Results:The results showed that there were highly significant(P≤0.05)differences in the genotypes’response to all salinity concentrations,Which led to decreasing germination percentage,delaying the average germination time,and decreasing radical/plumule length and seedling fresh/dry weight compared with a control.As noted genotypes(1524,1522 and 1514)were able to germinate in all concentrations of seawater,and gave the best average for all the studied traits.Also,the study indicated that a concentration of seawater of 40%was the most toxic for all wheat genotypes.The results of this study categorize the wheat genotypes into tolerant genotypes(1524,1522 and 1514),moderate tolerant(1492,1536),and sensitive(1398,1538,1544,1550 and 1562).Conclusion:The results concluded that the possibility of wheat crops agriculture into tolerant in Libyan coastal locations in which seawater concentration did not exceed 30%.展开更多
Photocatalytic H_(2) evolution from seawater splitting presents a promising approach to tackle the fossil energy crisis and mitigate carbon emission due to the abundant source of seawater and sunlight on the earth.How...Photocatalytic H_(2) evolution from seawater splitting presents a promising approach to tackle the fossil energy crisis and mitigate carbon emission due to the abundant source of seawater and sunlight on the earth.However,the development of efficient photocatalysts for seawater splitting remains a formidable challenge.Herein,a 2D/2D ZnIn_(2)S_(4)/WO_(3)(ZIS/WO_(3))heterojunction nanostructure is fabricated to efficiently separate the photoinduced carriers by steering electron transfer from the conduction band minimum of WO_(3) to the valence band maximum of ZIS via constructing internal electric field.Subsequently,plasmonic Au nanoparticles(NPs)as a novel photosensitizer and a reduction cocatalyst are anchored on ZIS/WO_(3) surface to further enhance the optical absorption of ZIS/WO_(3) heterojunction and accelerate the catalytic conversion.The obtained Au/ZIS/WO_(3) photocatalyst exhibits an outstanding H_(2) evolution rate of 2610.6 or 3566.3μmol g^(-1)h~(-1)from seawater splitting under visible or full-spectrum light irradiation,respectively.These rates represent an impressive increase of approximately 7.3-and 6,6-fold compared to those of ZIS under the illumination of the same light source.The unique 2D/2D structure,internal electric field,and plasmonic metal modification together boost the photocatalytic H_(2) evolution rate of Au/ZIS/WO_(3),making it even comparable to H_(2) evolution from pure water splitting.The present work sheds light on the development of efficient photocatalysts for seawater splitting.展开更多
In the maritime industry, cost-effective and lightweight Fiber Reinforced Polymer (FRP) composites offer excellent mechanical properties, design flexibility, and corrosion resistance. However, their reliability in har...In the maritime industry, cost-effective and lightweight Fiber Reinforced Polymer (FRP) composites offer excellent mechanical properties, design flexibility, and corrosion resistance. However, their reliability in harsh seawater conditions is a concern. Researchers address this by exploring three approaches: coating fiber surfaces, hybridizing fibers and matrices with or without nanofillers, and interply rearrangement. This study focuses on evaluating the synergistic effects of interply rearrangement of glass/carbon fibers and hybrid nanofillers, specifically Multi-walled carbon nanotubes (MWCNT) and Halloysite nanotubes (HNT). The aim is to enhance impact properties by minimizing moisture absorption. Hybrid nanocomposites with equal-weight proportions of two nanofillers: 0 wt.%, 1 wt.%, and 2 wt.% were exposed to seawater for 90 days. Experimental data was subjected to modelling through the application of Predictive Fick’s Law. The study found that the hybrid composite containing 2 wt.% hybrid nanofillers exhibited a 22.10% increase in impact performance compared to non-modified counterparts. After 90 days of seawater aging, the material exhibited enhanced resistance to moisture absorption (15.74%) and minimal reduction in impact strength (8.52%) compared to its dry strength, with lower diffusion coefficients.展开更多
Starting from the corrosion mechanism,this paper analyzes the characteristics of various types of stainless steel and selects the best performance composite plate composite plate stainless steel.Analyze and select the...Starting from the corrosion mechanism,this paper analyzes the characteristics of various types of stainless steel and selects the best performance composite plate composite plate stainless steel.Analyze and select the most suitable corrosion detection method based on specific practical multi working conditions,discuss the interference factors that affect metal corrosion during experimental simulation,and the advantages of newly developed sheet metal.The new development of composite board panels,with the substrate and composite materials applying their respective capabilities for MED,will bring breakthrough progress to the scientific research and engineering applica-tion of composite boards.展开更多
Hydrogen has been regarded as a promising renewable and green energy source to meet energy needs and attain net-zero carbon emissions.The electrolysis of seawater to make hydrogen is one of the fascinating development...Hydrogen has been regarded as a promising renewable and green energy source to meet energy needs and attain net-zero carbon emissions.The electrolysis of seawater to make hydrogen is one of the fascinating developments of the twenty-first century.This method uses abundant and relatively inexpensive seawater,as opposed to freshwater,which is rare and can be prohibitively expensive.In recent years,significant research and advancements have been made in direct seawater electrolysis technology for hydrogen production.However,producing highly effective and efficient electrocatalysts with long-term viability under harsh corrosive conditions remains a challenging and severe topic for large-scale seawater electrolysis technology.There is still a large accomplishment gap in understanding how to improve seawater electrolysis to increase hydrogen yields and prolong stability.It is,therefore,crucial to have a condensed knowledge of the tunable and inherent interactions between various electrocatalysts,covering electrolyzer types and paying particular attention to those with high efficiency,chemical stability,and conductivity.The extensive discussion is structured into a progression from noble metals to base metal compounds such as oxides,alloys,phosphides,chalcogenides,hydroxides,and nitrides,MXene-based complexes with a concise examination of hybrid electrocatalysts.In addition,proton exchange membranes,anion exchange membranes,alkaline water electrolyzers,and high-temperature water electrolyzers were potential contributors to seawater’s electrolysis.An extensive assessment of the techno-feasibility,economic insights,and future suggestions was done to commercialize the most efficient electrocatalytic systems for hydrogen production.This review is anticipated to provide academics,environmentalists,and industrial researchers with valuable ideas for constructing and modifying seawater-based electrocatalysts.展开更多
The epitaxial heterostructure can be rationally designed based on the in situ growth of two compatible phases with lattice similarity,in which the modulated electronic states and tuned adsorption behaviors are conduci...The epitaxial heterostructure can be rationally designed based on the in situ growth of two compatible phases with lattice similarity,in which the modulated electronic states and tuned adsorption behaviors are conducive to the enhancement of electrocatalytic activity.Herein,theoretical simulations first disclose the charge transfer trend and reinforced inherent electron conduction around the epitaxial heterointerface between Ru clusters and Ni_(3)N substrate(cRu-Ni_(3)N),thus leading to the optimized adsorption behaviors and reduced activation energy barriers.Subsequently,the defectrich nanosheets with the epitaxially grown cRu-Ni_(3)N heterointerface are successfully constructed.Impressively,by virtue of the superiority of intrinsic activity and reaction kinetics,such unique epitaxial heterostructure exhibits remarkable bifunctional catalytic activity toward electrocatalytic OER(226 mV@20 mA cm^(−2))and HER(32 mV@10 mA cm^(−2))in alkaline media.Furthermore,it also shows great application prospect in alkaline freshwater and seawater splitting,as well as solar-to-hydrogen integrated system.This work could provide beneficial enlightenment for the establishment of advanced electrocatalysts with epitaxial heterointerfaces.展开更多
The novel pulsed liquid chromatography radionuclide separation method presented here provides a new and promising strategy for the extraction of uranium from seawater.In this study,a new chromatographic separation met...The novel pulsed liquid chromatography radionuclide separation method presented here provides a new and promising strategy for the extraction of uranium from seawater.In this study,a new chromatographic separation method was proposed,and a pulsed nuclide automated separation device was developed,alongside a new chromatographic column.The length of this chromatographic column was 10 m,with an internal warp of 3 mm and a packing size of 1 mm,while the total separation units of the column reached 12,250.The most favorable conditions for the separation of nuclides were then obtained through optimizing the separation conditions of the device:Sample pH in the column=2,sample injection flow rate=5.698 mL/min,chromatographic column heating temperature=60℃.Separation experiments were also carried out for uranium,europium,and sodium ions in mixed solutions;uranium and sodium ions in water samples from the Ganjiang River;and uranium,sodium,and magnesium ions from seawater samples.The separation factors between the different nuclei were then calculated based on the experimental data,and a formula for the separation level was derived.The experimental results showed that the separation factor in the mixed solution of uranium and europium(1:1)was 1.088,while achieving the initial separation of uranium and europium theoretically required a 47-stage separation.Considering the separation factor of 1.50for the uranium and sodium ions in water samples from the Ganjiang River,achieving the initial separation of uranium and sodium ions would have theoretically required at least a 21-stage separation.Furthermore,for the seawater sample separation experiments,the separation factor of uranium and sodium ions was 1.2885;therefore,more than 28 stages of sample separation would be required to achieve uranium extraction from seawater.The novel pulsed liquid chromatography method proposed in this study was innovative in terms of uranium separation and enrichment,while expanding the possibilities of extracting uranium from seawater through chromatography.展开更多
The development of highly efficient OER catalysts with superior durability for seawater electrolysis and Zn-air battery is important but challenging.Herein,the vacancy-modified heterostructured bimetallic Fe Mo S_(x)/...The development of highly efficient OER catalysts with superior durability for seawater electrolysis and Zn-air battery is important but challenging.Herein,the vacancy-modified heterostructured bimetallic Fe Mo S_(x)/Co Ni P_(x)OER electrocatalyst is exploited.Benefiting from the electron redistribution and reaction kinetics modulation resulting from vacancy introduction and heterojunction formation,it yields ultralow OER overpotentials of 196,276,303 m V in 1 M KOH and 197,318,348 m V in 1 M KOH+seawater at 10,500,1000 m A cm^(-2),respectively,surviving 600 h at 800 m A cm^(-2)without obvious decay.Further,FeMoS_(x)/CoNiP_(x)-based Zn-air battery not only affords the high peak power density of 214.5 m W cm^(-2)but also exhibits the small voltage gap of 0.698 V and long lifetime of 500 h at 10 m A cm^(-2),overmatching overwhelming majority of reported advanced catalysts.It is revealed experimentally that the OER process on rationally designed Fe Mo S_(x)/Co Ni P_(x)follows the adsorbate evolution mechanism and the ratedetermining step shifts from^(*)OOH formation in individual building blocks to^(*)OOH deprotonation process in FeMoS_(x)/CoNiP_(x),providing the directly proof of how the vacancy introduction and heterojunction formation affect the reaction kinetics.展开更多
Electrochemical water splitting to produce hydrogen fuel is a promising renewable energy-conversion technique.Large-scale electrolysis of freshwater may deplete water resources and cause water scarcity worldwide.Thus,...Electrochemical water splitting to produce hydrogen fuel is a promising renewable energy-conversion technique.Large-scale electrolysis of freshwater may deplete water resources and cause water scarcity worldwide.Thus,seawater electrolysis is a potential solution to the future energy and water crisis.In seawater electrolysis,it is critical to develop cost-effective electrocatalysts to split seawater without chloride corrosion.Herein,we present zinc-doped nickel iron(oxy)hydroxide nanocubes passivated by negatively charged polyanions(NFZ-PBA-S)that exhibits outstanding catalytic activity,stability,and selectivity for seawater oxidation.Zn dopants and polyanion-rich passivated surface layers in NFZ-PBA-S could effectively repel chlorine ions and enhance corrosion resistance,enabling its excellent catalytic activity and stability for seawater oxidation.展开更多
Direct collection of uranium from low uranium systems via adsorption remains challenging.Fibrous sorbent materials with amidoxime(AO)groups are promising adsorbents for uranium extraction from seawater.However,low AO ...Direct collection of uranium from low uranium systems via adsorption remains challenging.Fibrous sorbent materials with amidoxime(AO)groups are promising adsorbents for uranium extraction from seawater.However,low AO adsorption group utilization remains an issue.We herein fabricated a branched structure containing AO groups on polypropylene/polyethylene spun-laced nonwoven(PP/PE SNW)fibers using grafting polymerization induced by radiation(RIGP)to improve AO utilization.The chemical structures,thermal properties,and surface morphologies of the raw and treated PP/PE SNW fibers were studied.The results show that an adsorptive functional layer with a branching structure was successfully anchored to the fiber surface.The adsorption properties were investigated using batch adsorption experiments in simulated seawater with an initial uranium concentration of 500μg·L^(−1)(pH 4,25℃).The maximum adsorption capacity of the adsorbent material was 137.3 mg·g^(−1)within 24 h;moreover,the uranyl removal reached 96%within 240 min.The adsorbent had an AO utilization rate of 1/3.5 and was stable over a pH range of 4–10,with good selectivity and reusability,demonstrating its potential for seawater uranium extraction.展开更多
Electrocatalytic splitting of water by means of renewable energy as the electricity supply is one of the most promising methods for storing green renewable energy as hydrogen. Although two-thirds of the earth’s surfa...Electrocatalytic splitting of water by means of renewable energy as the electricity supply is one of the most promising methods for storing green renewable energy as hydrogen. Although two-thirds of the earth’s surface is covered with water, there is inadequacy of freshwater in most parts of the world. Hence, splitting seawater instead of freshwater could be a truly sustainable alternative. However, direct seawater splitting faces challenges because of the complex composition of seawater. The composition, and hence, the local chemistry of seawater may vary depending on its origin, and in most cases, tracking of the side reactions and standardizing and customizing the catalytic process will be an extra challenge. The corrosion of catalysts and competitive side reactions due to the presence of various inorganic and organic pollutants create challenges for developing stable electro-catalysts. Hence, seawater splitting generally involves a two-step process, i.e., purification of seawater using reverse osmosis and then subsequent fresh water splitting. However, this demands two separate chambers and larger space, and increases complexity of the reactor design. Recently, there have been efforts to directly split seawater without the reverse osmosis step. Herein, we represent the most recent innovative approaches to avoid the two-step process, and compare the potential application of membrane-assisted and membrane-less electrolyzers in direct seawater splitting(DSS). We particularly discuss the device engineering, and propose a novel electrolyzer design strategies for concentration gradient based membrane-less microfluidic electrolyzer.展开更多
Cadmium(Cd)isotopes in seawater have been proven as an important geochemical tool for tracing ocean Cd circulation in the modern ocean.In this study,we evaluated a new method to separate Cd(*60 ng)from seawater using ...Cadmium(Cd)isotopes in seawater have been proven as an important geochemical tool for tracing ocean Cd circulation in the modern ocean.In this study,we evaluated a new method to separate Cd(*60 ng)from seawater using Chelex resin(1.0 g)coupled with AG-MP-1M resin.The results show that the Chelex resin is suffi-cient to remove Cd from Na and Mg matrix with Cd recoveries at 98.3±3.5%(2SD,N=6);while AG-MP-1M resin could separate Cd from the residual Na,Mg,and isobaric inferences.The total Cd recoveries of the method are 96.3±1.5%(2SD;N=4)and the salinity of the samples has no significant impacts on Cd recovery.Cd isotope ratios were measured using a Nu PlasmaⅢMC-ICP-MS and^(111)Cd–^(110)Cd double spike technique.By comparing theδ^(114/110)Cd values(0.00±0.06%)of synthetic seawaters doped with Cd isotope standard(NIST-3108;treated by Chelex+AG-MP-1M resin)and the reference value(-0.00%),no variations were observed.We also analyzed the Cd isotope compositions of three deep seawaters from a column at the Southwest Indian Ocean Ridges(SWIR).Theδ^(114/110)Cd values of the col-umn are decreased from 1.05±0.05%at 3200 m to 0.36±0.05%at 2800 m,differing from reportedδ^(114/110)Cd values of deep seawater in other oceans.Considering the spatial distance between the column and active hydrothermal vents in SWIR(-13 km),we propose that such positiveδ^(114/110)Cd values of deep seawater were likely contaminated by vent fluids,which could provide heavy Cd isotope to deep seawaters.This study demon-strates that Cd isotope is more sufficient to distinguish the impact of plumes on deep seawater.展开更多
基金Funded by the National Natural Science Foundation of China (Nos. 52278269, 52278268, 52178264, 52108238)Tianjin Outstanding Young Scholars Science Fund Project (No. 22JCJQJC00020)State Key Laboratory of Green Building Materials Open Foundation (No. 2021GBM08)。
文摘To explore the role of biofilm formation on the corrosion of marine concrete structures, we investigated the attachment of biofilm on mortar surfaces in simulated seawater and the influence of biofilm on the microstructure of mortar surfaces. The results show that the evolution of biofilm on mortar surfaces in simulated seawater is closely related to the corrosion suffered by the mortar, and the process of biofilm attachment and shedding is continuous and cyclical. It is found that the specimens in the absence of biofilm attachment are more severely eroded internally by the corrosive medium in simulated seawater than those in the presence of biofilm attachment. For the specimens without biofilm attachment, after 60 days, gypsum forms,and after 120 days, the number of pores in the mortar is reduced. In contrast, for the specimens in the presence of biofilm attachment, gypsum could only be detected after 90 days, and fewer pores are filled. Therefore, the formation of biofilm could delay the invasion of the corrosive medium into the interior of mortar during the evolution of biofilm on mortar surfaces, mitigating the corrosion of mortars in seawater.
基金The General Program of National Natural Science Foundation of China under contract No.42074150。
文摘In the processing of conventional marine seismic data,seawater is often assumed to have a constant velocity model.However,due to static pressure,temperature difference and other factors,random disturbances may often frequently in seawater bodies.The impact of such disturbances on data processing results is a topic of theoretical research.Since seawater sound velocity is a difficult physical quantity to measure,there is a need for a method that can generate models conforming to seawater characteristics.This article will combine the Munk model and Perlin noise to propose a two-dimensional dynamic seawater sound velocity model generation method,a method that can generate a dynamic,continuous,random seawater sound velocity model with some regularity at large scales.Moreover,the paper discusses the influence of the inhomogeneity characteristics of seawater on wave field propagation and imaging.The results show that the seawater sound velocity model with random disturbance will have a significant influence on the wave field simulation and imaging results.
基金the funding support from the National Natural Science Foundation of China (U22A2078)the Fundamental Research Funds of Central Universities (2022CDJQY-007 and 2022CDJJCLK001)
文摘The development of efficient and robust anode materials for stable alkaline seawater electrolysis is severely limited by chlorine evolution reaction and chloride corrosion.Here,the sulfur-doped cobalt-nickel bimetallic phosphides(CoNiPS)are specifically designed as a pre-catalyst for navigating a surface reconstruction to fabricate the anions(PO^(3-)_(4) and SO^(2-)_(4))-decorated Co(Ni)OOH catalyst(R-CoNiPS)with exceptional durability and high activity for stable alkaline seawater oxidation(ASO).Various experiment techniques together with theoretical simulations both demonstrate that the in situ-generated PO^(3-)_(4) and SO^(2-)_(4) anions on catalyst surface can improve the oxygen evolution reaction(OER)activity,regulating and stabilizing the catalytic active species Co(Ni)OOH,as well as make a critical role in inhibiting the adsorp-tion of chloride ions and extending the service life of electrode.Therefore,this R-CoNiPS electrode exhi-bits superb OER activity toward AsO and stands out among the non-precious ASO electrocatalysts reported recently,requiring low overpotentials of 420 and 440 mV to attain large current densities of 500 and 1000 mA cm^(-2) in an alkaline natural seawater electrolyte,respectively.Particularly,the catalyst displays a negligible chloride corrosion at room temperature during ASO operation(>200 h)at 500 mA cm^(-2).This work opens up a new viewpoint for designing high-activity and durable electrocata-lystsforseawaterelectrolysis.
基金supported by the National Natural Science Foundation of China(NSFC,No.22078052)the Fundamental Research Funds for the Central Universities(DUT22ZD207,DUT22LAB612)。
文摘Seawater splitting into hydrogen,a promising technology,is seriously limited by the durability and tolerance of electrocatalysts for chlorine ions in seawater at large current densities due to chloride oxidation and corrosion.Here,we present a robust and weak-nucleophilicity nickel-iron hydroxide electrocatalyst with excellent selectivity for oxygen evolution and an inert response for chlorine ion oxidation which are key and highly desired for efficient seawater electrolysis.Such a weak-nucleophilicity electrocatalyst can well match with strong-nucleophilicity OH-compared with the weak-nucleophilicity Cl^(-),resultantly,the oxidation of OH-in electrolyte can be more easily achieved relative to chlorine ion oxidation,confirmed by ethylenediaminetetraacetic acid disodium probing test.Further,no strongly corrosive hypochlorite is produced when the operating voltage reaches about 2.1 V vs.RHE,a potential that is far beyond the thermodynamic potential of chlorine ion oxidatio n.This concept and approach to reasonably designing weaknucleophilicity electrocatalysts that can greatly avoid chlorine ion oxidation under alkaline seawater environments can push forward the seawater electrolysis technology and also accelerate the development of green hydrogen technique.
基金support from the Free Exploration Project of Frontier Technology for Laoshan Laboratory(No.16-02)the National Natural Science Foundation of China(Nos.22072015 and 21927811)。
文摘Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation.Nevertheless,the direct electrolysis of seawater encounters significant challenges due to poor anodic stability caused by detrimental chlorine chemistry.Herein,we present our recent discovery that the incorporation of Ce into Ni Fe layered double hydroxide nanosheet array on Ni foam(Ce-Ni Fe LDH/NF)emerges as a robust electrocatalyst for seawater oxidation.During the seawater oxidation process,CeO_(2)is generated,effectively repelling Cl^(-)and inhibiting the formation of Cl O-,resulting in a notable enhancement in the oxidation activity and stability of alkaline seawater.The prepared Ce-Ni Fe LDH/NF requires only overpotential of 390 m V to achieve the current density of 1 A cm^(-2),while maintaining long-term stability for 500 h,outperforming the performance of Ni Fe LDH/NF(430 m V,150 h)by a significant margin.This study highlights the effectiveness of a Ce-doping strategy in augmenting the activity and stability of materials based on Ni Fe LDH in seawater electrolysis for oxygen evolution.
基金supported by the National Key Research and Development Program of China(2022YFB4002100)the Key Program of the National Natural Science Foundation of China(22090032,22090030)。
文摘Direct seawater electrolysis for hydrogen production has been regarded as a viable route to utilize surplus renewable energy and address the climate crisis.However,the harsh electrochemical environment of seawater,particularly the presence of aggressive Cl^(-),has been proven to be prone to parasitic chloride ion oxidation and corrosion reactions,thus restricting seawater electrolyzer lifetime.Herein,hierarchical structure(Ni,Fe)O(OH)@NiCoS nanorod arrays(NAs)catalysts with heterointerfaces and localized oxygen vacancies were synthesized at nickel foam substrates via the combination of hydrothermal and annealing methods to boost seawater dissociation.The hiera rchical nanostructure of NiCoS NAs enhanced electrode charge transfer rate and active surface area to accelerate oxygen evolution reaction(OER)and generated sulfate gradient layers to repulsive aggressive Cl^(-).The fabricated heterostructure and vacancies of(Ni,Fe)O(OH)tuned catalyst electronic structure into an electrophilic state to enhance the binding affinity of hydroxyl intermediates and facilitate the structural transformation into amorphousγ-NiFeOOH for promoting OER.Furthermore,through operando electrochemistry techniques,we found that theγ-NiFeOOH possessing an unsaturated coordination environment and lattice-oxygen-participated OER mechanism can minimize electrode Cl^(-)corrosion enabled by stabilizing the adsorption of OH*intermediates,making it one of the best OER catalysts in the seawater medium reported to date.Consequently,these catalysts can deliver current densities of 100 and 500 mA cm-2for boosting OER at minimal overpotentials of 245and 316 mV,respectively,and thus prevent chloride ion oxidation simultaneously.Impressively,a highly stable anion exchange membrane(AEM)seawater electrolyzer based on the non-noble metal heterostructure electrodes reached a record low degradation rate under 100μV h-1at constant industrial current densities of 400 and 600 mA cm-2over 300 h,which exhibits a promising future for the nonprecious and stable AEMWE in the direct seawater electrolysis industry.
文摘This study presents a significant contribution to the field of water quality assessment and sustainable water management practices. By evaluating the levels of total dissolved solids (TDS) in seawater intakes within Al-Khobar desalination production system, the study addresses a crucial aspect of water treatment and environmental impact assessment. The findings provide valuable insights into the variations and trends of TDS levels across different phases of the system, highlighting the importance of monitoring and management strategies. The study provided both gravimetric total dissolved solids (TDS) and electrical conductivity (EC) measurements to analyze TDS calculation factor and evaluate measurement accuracy. Results revealed significant variations in TDS levels across the sampling locations, with phase-2 exhibiting higher levels and greater fluctuations. Phase-3 displayed similar trends but with lower TDS levels, while phase-4 showed slightly different behavior with higher average TDS levels. EC measurements demonstrated a strong correlation with TDS, providing a reliable estimation. However, additional methods such as gravimetric analysis should be employed to confirm TDS measurements. The findings contribute to understanding water quality in the Al-Khobar desalination system, aiding in monitoring, management, and decision-making processes for water treatment and environmental impact assessment. The study enhances the credibility of water quality assessments and supports sustainable water management practices.
文摘This article examines the influence of seawater temperature and total dissolved solids (TDS) on reverse osmosis (RO) desalination in the Arabian Gulf region, with a focus on the impact of climate change. The study highlights the changes in seawater temperature and TDS levels over the years and discusses their effects on the efficiency and productivity of RO desalination plants. It emphasizes the importance of monitoring TDS levels and controlling seawater temperature to optimize water production. The article also suggests various solutions, including intensive pre-treatment, development of high-performance membranes, exploration of alternative water sources, and regulation of discharges into the Gulf, to ensure sustainable water supply in the face of rising TDS levels and seawater temperature. Further research and comprehensive monitoring are recommended to understand the implications of these findings and develop effective strategies for the management of marine resources in the Arabian Gulf.
文摘Objective:Seawater leakage in Al-Jabal Al-Akhdar East Libya's coastal areas is one of the most biggest obstacles to farmers obtaining a highly productive crop.As a result,the experiment was conducted in a laboratory to find out the impact of irrigation with seawater on the salt tolerance of Acsad Bread wheat genotypes.Method:Ten genotypes(1398,1492,1514,1522,1524,1536,1538,1544,1550,and 1562),obtained from the Arab Center for the Studies of Arid Zones and Dry Lands Acsad,were used in the study,10 seeds of each genotype with three repetitions were germinated under four seawater concentrations(10,20,30 and 40%).Results:The results showed that there were highly significant(P≤0.05)differences in the genotypes’response to all salinity concentrations,Which led to decreasing germination percentage,delaying the average germination time,and decreasing radical/plumule length and seedling fresh/dry weight compared with a control.As noted genotypes(1524,1522 and 1514)were able to germinate in all concentrations of seawater,and gave the best average for all the studied traits.Also,the study indicated that a concentration of seawater of 40%was the most toxic for all wheat genotypes.The results of this study categorize the wheat genotypes into tolerant genotypes(1524,1522 and 1514),moderate tolerant(1492,1536),and sensitive(1398,1538,1544,1550 and 1562).Conclusion:The results concluded that the possibility of wheat crops agriculture into tolerant in Libyan coastal locations in which seawater concentration did not exceed 30%.
基金supported by the National Natural Science Foundation of China(21872104,21501131,21978216 and 22272082)the Natural Science Foundation of Tianjin for Distinguished Young Scholar(20JCJQJC00150)the Analytical&Testing Center of Tiangong University for PL work。
文摘Photocatalytic H_(2) evolution from seawater splitting presents a promising approach to tackle the fossil energy crisis and mitigate carbon emission due to the abundant source of seawater and sunlight on the earth.However,the development of efficient photocatalysts for seawater splitting remains a formidable challenge.Herein,a 2D/2D ZnIn_(2)S_(4)/WO_(3)(ZIS/WO_(3))heterojunction nanostructure is fabricated to efficiently separate the photoinduced carriers by steering electron transfer from the conduction band minimum of WO_(3) to the valence band maximum of ZIS via constructing internal electric field.Subsequently,plasmonic Au nanoparticles(NPs)as a novel photosensitizer and a reduction cocatalyst are anchored on ZIS/WO_(3) surface to further enhance the optical absorption of ZIS/WO_(3) heterojunction and accelerate the catalytic conversion.The obtained Au/ZIS/WO_(3) photocatalyst exhibits an outstanding H_(2) evolution rate of 2610.6 or 3566.3μmol g^(-1)h~(-1)from seawater splitting under visible or full-spectrum light irradiation,respectively.These rates represent an impressive increase of approximately 7.3-and 6,6-fold compared to those of ZIS under the illumination of the same light source.The unique 2D/2D structure,internal electric field,and plasmonic metal modification together boost the photocatalytic H_(2) evolution rate of Au/ZIS/WO_(3),making it even comparable to H_(2) evolution from pure water splitting.The present work sheds light on the development of efficient photocatalysts for seawater splitting.
文摘In the maritime industry, cost-effective and lightweight Fiber Reinforced Polymer (FRP) composites offer excellent mechanical properties, design flexibility, and corrosion resistance. However, their reliability in harsh seawater conditions is a concern. Researchers address this by exploring three approaches: coating fiber surfaces, hybridizing fibers and matrices with or without nanofillers, and interply rearrangement. This study focuses on evaluating the synergistic effects of interply rearrangement of glass/carbon fibers and hybrid nanofillers, specifically Multi-walled carbon nanotubes (MWCNT) and Halloysite nanotubes (HNT). The aim is to enhance impact properties by minimizing moisture absorption. Hybrid nanocomposites with equal-weight proportions of two nanofillers: 0 wt.%, 1 wt.%, and 2 wt.% were exposed to seawater for 90 days. Experimental data was subjected to modelling through the application of Predictive Fick’s Law. The study found that the hybrid composite containing 2 wt.% hybrid nanofillers exhibited a 22.10% increase in impact performance compared to non-modified counterparts. After 90 days of seawater aging, the material exhibited enhanced resistance to moisture absorption (15.74%) and minimal reduction in impact strength (8.52%) compared to its dry strength, with lower diffusion coefficients.
文摘Starting from the corrosion mechanism,this paper analyzes the characteristics of various types of stainless steel and selects the best performance composite plate composite plate stainless steel.Analyze and select the most suitable corrosion detection method based on specific practical multi working conditions,discuss the interference factors that affect metal corrosion during experimental simulation,and the advantages of newly developed sheet metal.The new development of composite board panels,with the substrate and composite materials applying their respective capabilities for MED,will bring breakthrough progress to the scientific research and engineering applica-tion of composite boards.
基金the support provided by the Deanship of Scientific Research at Majmaah University,P.O.Box 66,Majmaah 11952,Saudi Arabia under Project No.R-2023-6Center for Refining and Advanced Chemicals,Research Institute,King Fahd University of Petroleum and Minerals(KFUPM),Saudi Arabia。
文摘Hydrogen has been regarded as a promising renewable and green energy source to meet energy needs and attain net-zero carbon emissions.The electrolysis of seawater to make hydrogen is one of the fascinating developments of the twenty-first century.This method uses abundant and relatively inexpensive seawater,as opposed to freshwater,which is rare and can be prohibitively expensive.In recent years,significant research and advancements have been made in direct seawater electrolysis technology for hydrogen production.However,producing highly effective and efficient electrocatalysts with long-term viability under harsh corrosive conditions remains a challenging and severe topic for large-scale seawater electrolysis technology.There is still a large accomplishment gap in understanding how to improve seawater electrolysis to increase hydrogen yields and prolong stability.It is,therefore,crucial to have a condensed knowledge of the tunable and inherent interactions between various electrocatalysts,covering electrolyzer types and paying particular attention to those with high efficiency,chemical stability,and conductivity.The extensive discussion is structured into a progression from noble metals to base metal compounds such as oxides,alloys,phosphides,chalcogenides,hydroxides,and nitrides,MXene-based complexes with a concise examination of hybrid electrocatalysts.In addition,proton exchange membranes,anion exchange membranes,alkaline water electrolyzers,and high-temperature water electrolyzers were potential contributors to seawater’s electrolysis.An extensive assessment of the techno-feasibility,economic insights,and future suggestions was done to commercialize the most efficient electrocatalytic systems for hydrogen production.This review is anticipated to provide academics,environmentalists,and industrial researchers with valuable ideas for constructing and modifying seawater-based electrocatalysts.
基金financially sponsored by the National Natural Science Foundation of China(Grant No.22075223,22179104)the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology)(2021-ZD-4)the Fundamental Research Funds for the Central Universities(No.2020-YB-012)。
文摘The epitaxial heterostructure can be rationally designed based on the in situ growth of two compatible phases with lattice similarity,in which the modulated electronic states and tuned adsorption behaviors are conducive to the enhancement of electrocatalytic activity.Herein,theoretical simulations first disclose the charge transfer trend and reinforced inherent electron conduction around the epitaxial heterointerface between Ru clusters and Ni_(3)N substrate(cRu-Ni_(3)N),thus leading to the optimized adsorption behaviors and reduced activation energy barriers.Subsequently,the defectrich nanosheets with the epitaxially grown cRu-Ni_(3)N heterointerface are successfully constructed.Impressively,by virtue of the superiority of intrinsic activity and reaction kinetics,such unique epitaxial heterostructure exhibits remarkable bifunctional catalytic activity toward electrocatalytic OER(226 mV@20 mA cm^(−2))and HER(32 mV@10 mA cm^(−2))in alkaline media.Furthermore,it also shows great application prospect in alkaline freshwater and seawater splitting,as well as solar-to-hydrogen integrated system.This work could provide beneficial enlightenment for the establishment of advanced electrocatalysts with epitaxial heterointerfaces.
基金the Natural Science Foundation of Jiangxi Province,China(No.20202BABL203004)the Opening Project of the State Key Laboratory of Nuclear Resources and Environment(East China University of Technology)(No.2022NRE23)the Opening Project of Jiangxi Province Key Laboratory of Polymer Micro/Nano Manufacturing and Devices(No.PMND202101).
文摘The novel pulsed liquid chromatography radionuclide separation method presented here provides a new and promising strategy for the extraction of uranium from seawater.In this study,a new chromatographic separation method was proposed,and a pulsed nuclide automated separation device was developed,alongside a new chromatographic column.The length of this chromatographic column was 10 m,with an internal warp of 3 mm and a packing size of 1 mm,while the total separation units of the column reached 12,250.The most favorable conditions for the separation of nuclides were then obtained through optimizing the separation conditions of the device:Sample pH in the column=2,sample injection flow rate=5.698 mL/min,chromatographic column heating temperature=60℃.Separation experiments were also carried out for uranium,europium,and sodium ions in mixed solutions;uranium and sodium ions in water samples from the Ganjiang River;and uranium,sodium,and magnesium ions from seawater samples.The separation factors between the different nuclei were then calculated based on the experimental data,and a formula for the separation level was derived.The experimental results showed that the separation factor in the mixed solution of uranium and europium(1:1)was 1.088,while achieving the initial separation of uranium and europium theoretically required a 47-stage separation.Considering the separation factor of 1.50for the uranium and sodium ions in water samples from the Ganjiang River,achieving the initial separation of uranium and sodium ions would have theoretically required at least a 21-stage separation.Furthermore,for the seawater sample separation experiments,the separation factor of uranium and sodium ions was 1.2885;therefore,more than 28 stages of sample separation would be required to achieve uranium extraction from seawater.The novel pulsed liquid chromatography method proposed in this study was innovative in terms of uranium separation and enrichment,while expanding the possibilities of extracting uranium from seawater through chromatography.
基金supported by the National Natural Science Foundation of China (21975136,22102076)the Fundamental Research Funds for the Central Universities (63185015)+2 种基金the Shenzhen Science,Technology and Innovation Committee (JCYJ20190808151603654,JCYJ20210324121002007)the Open Funds from National Engineering Lab for Mobile Source Emission Control Technology (NELMS2020A12)the Open Fund for Key Laboratory of Civil Aviation Thermal Hazards Prevention and Emergency Response (RZH2021-KF-03)。
文摘The development of highly efficient OER catalysts with superior durability for seawater electrolysis and Zn-air battery is important but challenging.Herein,the vacancy-modified heterostructured bimetallic Fe Mo S_(x)/Co Ni P_(x)OER electrocatalyst is exploited.Benefiting from the electron redistribution and reaction kinetics modulation resulting from vacancy introduction and heterojunction formation,it yields ultralow OER overpotentials of 196,276,303 m V in 1 M KOH and 197,318,348 m V in 1 M KOH+seawater at 10,500,1000 m A cm^(-2),respectively,surviving 600 h at 800 m A cm^(-2)without obvious decay.Further,FeMoS_(x)/CoNiP_(x)-based Zn-air battery not only affords the high peak power density of 214.5 m W cm^(-2)but also exhibits the small voltage gap of 0.698 V and long lifetime of 500 h at 10 m A cm^(-2),overmatching overwhelming majority of reported advanced catalysts.It is revealed experimentally that the OER process on rationally designed Fe Mo S_(x)/Co Ni P_(x)follows the adsorbate evolution mechanism and the ratedetermining step shifts from^(*)OOH formation in individual building blocks to^(*)OOH deprotonation process in FeMoS_(x)/CoNiP_(x),providing the directly proof of how the vacancy introduction and heterojunction formation affect the reaction kinetics.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF)funded by the Ministry of Science,ICT and Future Planning (2021R1A2C2091497 and 2022R1A2C2010162)supported by“Regional Innovation Strategy (RIS)”through the National Research Foundation of Korea (NRF)funded by the Ministry of Education (MOE) (2022RIS-005)+1 种基金supported by the Ministry of Trade,Industry,and Energy (20018145)supported by KIST Institutional Program (Project Nos.2V09781)。
文摘Electrochemical water splitting to produce hydrogen fuel is a promising renewable energy-conversion technique.Large-scale electrolysis of freshwater may deplete water resources and cause water scarcity worldwide.Thus,seawater electrolysis is a potential solution to the future energy and water crisis.In seawater electrolysis,it is critical to develop cost-effective electrocatalysts to split seawater without chloride corrosion.Herein,we present zinc-doped nickel iron(oxy)hydroxide nanocubes passivated by negatively charged polyanions(NFZ-PBA-S)that exhibits outstanding catalytic activity,stability,and selectivity for seawater oxidation.Zn dopants and polyanion-rich passivated surface layers in NFZ-PBA-S could effectively repel chlorine ions and enhance corrosion resistance,enabling its excellent catalytic activity and stability for seawater oxidation.
基金supported by the National Natural Science Foundation of China(Nos.11675247,22176194).
文摘Direct collection of uranium from low uranium systems via adsorption remains challenging.Fibrous sorbent materials with amidoxime(AO)groups are promising adsorbents for uranium extraction from seawater.However,low AO adsorption group utilization remains an issue.We herein fabricated a branched structure containing AO groups on polypropylene/polyethylene spun-laced nonwoven(PP/PE SNW)fibers using grafting polymerization induced by radiation(RIGP)to improve AO utilization.The chemical structures,thermal properties,and surface morphologies of the raw and treated PP/PE SNW fibers were studied.The results show that an adsorptive functional layer with a branching structure was successfully anchored to the fiber surface.The adsorption properties were investigated using batch adsorption experiments in simulated seawater with an initial uranium concentration of 500μg·L^(−1)(pH 4,25℃).The maximum adsorption capacity of the adsorbent material was 137.3 mg·g^(−1)within 24 h;moreover,the uranyl removal reached 96%within 240 min.The adsorbent had an AO utilization rate of 1/3.5 and was stable over a pH range of 4–10,with good selectivity and reusability,demonstrating its potential for seawater uranium extraction.
基金King Abdullah University of Science and Technology for funding through the funding grant (BAS/1/1413-01-01)the Engineering and Physical Sciences Research Council (EPSRC,EP/V027433/1)+1 种基金the Royal Society (RGSR1211080IESR2212115)。
文摘Electrocatalytic splitting of water by means of renewable energy as the electricity supply is one of the most promising methods for storing green renewable energy as hydrogen. Although two-thirds of the earth’s surface is covered with water, there is inadequacy of freshwater in most parts of the world. Hence, splitting seawater instead of freshwater could be a truly sustainable alternative. However, direct seawater splitting faces challenges because of the complex composition of seawater. The composition, and hence, the local chemistry of seawater may vary depending on its origin, and in most cases, tracking of the side reactions and standardizing and customizing the catalytic process will be an extra challenge. The corrosion of catalysts and competitive side reactions due to the presence of various inorganic and organic pollutants create challenges for developing stable electro-catalysts. Hence, seawater splitting generally involves a two-step process, i.e., purification of seawater using reverse osmosis and then subsequent fresh water splitting. However, this demands two separate chambers and larger space, and increases complexity of the reactor design. Recently, there have been efforts to directly split seawater without the reverse osmosis step. Herein, we represent the most recent innovative approaches to avoid the two-step process, and compare the potential application of membrane-assisted and membrane-less electrolyzers in direct seawater splitting(DSS). We particularly discuss the device engineering, and propose a novel electrolyzer design strategies for concentration gradient based membrane-less microfluidic electrolyzer.
基金supported by the National Natural Science Foundation of China(Grant No.42073010)the Key Research and Development Program of Yunnan Province(Grant No.202103AQ100003)a special fund managed by the State Key Laboratory of Ore Deposit Geochemistry,Chinese Academy of Sciences.
文摘Cadmium(Cd)isotopes in seawater have been proven as an important geochemical tool for tracing ocean Cd circulation in the modern ocean.In this study,we evaluated a new method to separate Cd(*60 ng)from seawater using Chelex resin(1.0 g)coupled with AG-MP-1M resin.The results show that the Chelex resin is suffi-cient to remove Cd from Na and Mg matrix with Cd recoveries at 98.3±3.5%(2SD,N=6);while AG-MP-1M resin could separate Cd from the residual Na,Mg,and isobaric inferences.The total Cd recoveries of the method are 96.3±1.5%(2SD;N=4)and the salinity of the samples has no significant impacts on Cd recovery.Cd isotope ratios were measured using a Nu PlasmaⅢMC-ICP-MS and^(111)Cd–^(110)Cd double spike technique.By comparing theδ^(114/110)Cd values(0.00±0.06%)of synthetic seawaters doped with Cd isotope standard(NIST-3108;treated by Chelex+AG-MP-1M resin)and the reference value(-0.00%),no variations were observed.We also analyzed the Cd isotope compositions of three deep seawaters from a column at the Southwest Indian Ocean Ridges(SWIR).Theδ^(114/110)Cd values of the col-umn are decreased from 1.05±0.05%at 3200 m to 0.36±0.05%at 2800 m,differing from reportedδ^(114/110)Cd values of deep seawater in other oceans.Considering the spatial distance between the column and active hydrothermal vents in SWIR(-13 km),we propose that such positiveδ^(114/110)Cd values of deep seawater were likely contaminated by vent fluids,which could provide heavy Cd isotope to deep seawaters.This study demon-strates that Cd isotope is more sufficient to distinguish the impact of plumes on deep seawater.