Compositional engineering of HKUST-1/sulfidized NiMn-LDH on functionalized MWCNTs as remarkable bifunctional electrocatalysts for water splitting

Water-splitting reactions such as the hydrogen evolution reaction(HER)and the oxygen evolution reaction(OER)typically require expensive noble metal-based electrocatalysts.This has motivated researchers to develop novel,cost-effective electrocatalytic systems.In this study,a new multicomponent nanocomposite was assembled by combining functionalized multiwalled carbon nanotubes,a Cu-based metal–organic framework(MOF)(HKUST-1 or HK),and a sulfidized NiMn-layered double hydroxide(NiMn-S).The resulting nanocomposite,abbreviated as MW/HK/NiMn-S,features a unique architecture,high porosity,numerous electroactive Cu/Ni/Mn sites,fast charge transfer,excellent structural stability,and conductivity.At a current density of 10 mA cm-2,this dual-function electrocatalyst shows remarkable performance,with ultralow overpotential values of 163 mV(OER)or 73 mV(HER),as well as low Tafel slopes(57 and 75 mV dec-1,respectively).Additionally,its high turnover frequency values(4.43 s-1 for OER;3.96 s-1 for HER)are significantly superior to those of standard noble metal-based Pt/C and IrO2 systems.The synergistic effect of the nanocomposite's different components is responsible for its enhanced electrocatalytic performance.A density functional theory study revealed that the multi-interface and multicomponent heterostructure contribute to increased electrical conductivity and decreased energy barrier,resulting in superior electrocatalytic HER/OER activity.This study presents a novel vision for designing advanced electrocatalysts with superior performance in water splitting.Various composites have been utilized in water-splitting applications.This study investigates the use of the MW/HK/NiMn-S electrocatalyst for water splitting for the first time to indicate the synergistic effect between carbon-based materials along with layered double hydroxide compounds and porous compounds of MOF.The unique features of each component in this composite can be an interesting topic in the field of water splitting.

Reversed charge transfer induced by nickel in Fe-Ni/Mo_(2)C@nitrogen-doped carbon nanobox for promoted reversible oxygen electrocatalysis

The interaction between metal and support is critical in oxygen catalysis as it governs the charge transfer between these two entities,influences the electronic structures of the supported metal,affects the adsorption energies of reaction intermediates,and ultimately impacts the catalytic performance.In this study,we discovered a unique charge transfer reversal phenomenon in a metal/carbon nanohybrid system.Specifically,electrons were transferred from the metal-based species to N-doped carbon,while the carbon support reciprocally donated electrons to the metal domain upon the introduction of nickel.This led to the exceptional electrocatalytic performances of the resulting Ni-Fe/Mo_(2)C@nitrogen-doped carbon catalyst,with a half-wave potential of 0.91 V towards oxygen reduction reaction(ORR)and a low overpotential of 290 m V at 10 mA cm^(-2)towards oxygen evolution reaction(OER)under alkaline conditions.Additionally,the Fe-Ni/Mo_(2)C@carbon heterojunction catalyst demonstrated high specific capacity(794 mA h g_(Zn)~(-1))and excellent cycling stability(200 h)in a Zn-air battery.Theoretical calculations revealed that Mo_(2)C effectively inhibited charge transfer from Fe to the support,while secondary doping of Ni induced a charge transfer reversal,resulting in electron accumulation in the Fe-Ni alloy region.This local electronic structure modulation significantly reduced energy barriers in the oxygen catalysis process,enhancing the catalytic efficiency of both ORR and OER.Consequently,our findings underscore the potential of manipulating charge transfer reversal between the metal and support as a promising strategy for developing highly-active and durable bi-functional oxygen electrodes.

A high‐performance transition‐metal phosphide electrocatalyst for converting solar energy into hydrogen at 19.6% STH efficiency

The construction of high-efficiency and low-cost non-noble metal bifunctional electrocatalysts for water electrolysis is crucial for commercial large-scale application of hydrogen energy.Here,we report a novel strategy with erbiumdoped NiCoP nanowire arrays in situ grown on conductive nickel foam(Er-NiCoP/NF).Significantly,the developed electrode shows exceptional bifunctional catalytic activity,which only requires overpotentials of 46 and 225 mV to afford a current density of 10 mAcm^(−2) for the hydrogen evolution reaction(HER)and the oxygen evolution reaction(OER),respectively.Density functional theory calculations reveal that the appropriate Er incorporation into the NiCoP lattice can significantly modulate the electronic structure with the d-band centers of Ni and Co atoms by shifting to lower energies with respect to the Fermi level,and optimize the Gibbs free energies of HER/OER intermediates,thereby accelerating water-splitting kinetics.When assembled as a solar-driven overall water-splitting electrolyzer,the as-prepared electrode shows a high and stable solar-to-hydrogen efficiency of 19.6%,indicating its potential for practical storage of intermittent energy.

Heterostructured bimetallic phosphide nanowire arrays with latticetorsion interfaces for efficient overall water splitting

Designing cost-effective and high-efficiency electrocatalysts is critical to the water splitting performance during hydrogen generation.Herein,we have developed Fe_(2)P-Co_(2)P heterostructure nanowire arrays with excellent lattice torsions and grain boundaries for highly efficient water splitting.According to the microstructural investigations and theoretical calculations,the lattice torsion interface not only contributes to the exposure of more active sites but also effectively tunes the adsorption energy of hydrogen/oxygen intermediates via the accumulation of charge redistribution.As a result,the Fe_(2)P-Co_(2)P heterostructure nanowire array exhibits exceptional bifunctional catalytic activity with overpotentials of 65 and 198 mV at 10 mA cm^(-2) for hydrogen and oxygen evolution reactions,respectively.Moreover,the Fe_(2)P-Co_(2)P/NF-assembled electrolyzer can deliver 10 mA cm^(-2) at an ultralow voltage of1.51 V while resulting in a high solar-to-hydrogen conversion efficiency of 19.8%in the solar-driven water electrolysis cell.

Boron modulating electronic structure of FeN4C to initiate high-efficiency oxygen reduction reaction and high-performance zinc-air battery

The biggest challenge is to develop a low cost and readily available catalyst to replace expensive commercial Pt/C for efficient electrochemical oxygen reduction reaction(ORR).In this research,closo-[B_(12)H_(12)]^(2−)and 1,10-phenanthroline-iron complexes were introduced into the porous metal-organic framework by impregnation method,and further annealing treatment achieved the successful anchoring of single-atom-Fe in B-doped CN Matrix(FeN4CB).The ORR activity of FeN4CB is comparable to the widely used commercial 20 wt%Pt/C.Where the half-wave potential(E_(1/2))in alkaline medium up to 0.84 V,and even in the face of challenging ORR in acidic medium,the E_(1/2)of ORR driven by FeN4CB is still as high as 0.81 V.When FeN4CB was used as air cathode,the open circuit voltage of Zn-air battery reaches 1.435 V,and the power density and specific capacity are as high as 177 mW cm^(−2)and 800 mAh g_(Zn)^(−1)(theoretical value:820 mAh g_(Zn)^(−1)),respectively.The dazzling point of FeN4CB also appears in the high ORR stability,whether in alkaline or acidic media,E_(1/2)and limiting current density are still close to the initial value after 5000 times cycles.After continuously running the charge-discharge test for 220 h,the charge voltage and discharge voltage of the rechargeable zinc-air battery with FeN4CB as the air cathode maintained the initial state.Density functional theory calculations reveals that introducing B atom to Fe–N4–C can adjust the electronic structure to easily break O=O bond and significantly reduce the energy barrier of the rate-determining step resulting in an improved ORR activity.

Numerical Simulation of Dynamic Response of A Net Cage for Flatfish in Waves

A numerical model of flatfish cage is built based on the lumped mass method and the principle of rigid body kinematics.To validate the numerical model,a series of physical model tests are conducted in the wave flume.The numerical results correspond well with the data sets from physical model test.The effect of weight of bottom frame,height of fish net and net shape on motion responses of fish cage and tension force on mooring lines is then analyzed.The results indicate that the vertical displacements of float collar and bottom frame decrease with the increase in the weight of bottom frame;the maximum tension force on mooring lines increases with the increasing weight of bottom frame.The inclination angles of float collar and bottom frame decrease with the increasing net height;the maximum tension force increases obviously with the increase of net height.

Profile and development of microsatellite primers for Acanthogobius ommaturus based on high-throughput sequencing technology

Acanthogobius ommaturus,a fish species of the Family Gobiidae,is a marine commercial fish perched on the bottom of seawater.In this study,Illumina high-throughput sequencing technology was applied to obtain the candidate microsatellite markers of A.ommaturus.A total of 4746 microsatellite-rich fragments were found,of which 4542 microsatellites are with primer fragments,containing 971 dinucleotide sequences,2643 trinucleotide sequences,569 tetranucleotide sequences,406 pentanucleotide sequences,and 212 hexanucleotide sequences.Based on the results of high-throughput sequencing,a total of 141 pairs of the microsatellite primers were designed and screened.And then 24 polymorphic primers were finally obtained by polyacrylamide gel electrophoresis.In total,271 alleles were detected in the 24 pairs of primers.The number of alleles for different primers ranged from 5 to 19.The average number of effective alleles(Na)was 11.292;the average observed heterozygosity(Ho)of the 24 pairs of primers was 0.665,the average expected heterozygosity(He)was 0.880,and the average polymorphic information content was 0.846.All sites were highly polymorphic(PIC>0.50).

Population Genetic Analysis of Sillago nigrofasciata (Perciformes:Sillaginidae) Along the Coast of China by Sequencing Mitochondrial DNA Control Region

Sillago nigrofasciata, a small to moderate size nearshore species, is newly found along the eastern and southern coasts of China. The present study is carried out in order to analyze the population genetics of the S. nigrofasciata. The control region sequence of mitochondrial DNA revealing 73 haplotypes were obtained from 162 individuals collected at 8 locations along the coast of China. The whole S. nigrofasciata population along the coast of China showed a low nucleotide diversity(0.012) and a high population diversity(haplotype diversity)(0.943), and all the 8 local populations showed low nucleotide diversities(0.014 – 0.001), suggesting the protective measures are effective. The haplotypes of the 8 local populations were widely distributed in haplotype network diagram and neighbor-joining phylogenetic tree, while no branch associating with sampling locations was detected. Recent gene flow analysis showed asymmetric gene exchanges among local populations. The pairwise FST values and unweighted pair-group method with arithmetic mean(UPGMA) tree revealed a certain amount of genetic difference among local populations. Moreover, analysis of molecular variance(AMOVA) reflected genetic differences between hypothetical subdivision groups. Neutral test and mismatch distribution of pairwise nucleotide suggested S. nigrofasciata may have experienced recent population expansion events. The historical geographic events associating with ice age may be the main explanation to the heterogeneity among local populations with short geographic distances, and the homogeneity among local populations with long geographic distances.

Identification of Species in Genus Platycephalus from Seas of China

Platycephalus in Chinese sea area has a high commercial value.However,there were mis-identifications in previous records.In this study,we fully distinguished and diagnosed all five species,Platycephalus indicus,P.cultellatus,Platycephalus sp.,Platycephalus sp.1 and Platycephalus sp.2.The results revealed that P.cultellatus was overlooked by previous ichthyologists.Platycephalus sp.1 was misidentified as P.indicus in reality,and Platycephalus sp.2 only existed in the seas of Japan.Furthermore,morphological,especially phylogenetic analysis indicated that Platycephalus sp.from South China Sea differs from all former known species,which might be a new species.We identified all Platycephalus species in China seas for the first time,which will contribute to local species identification,biodiversity conservation and sustainable exploitation of Platycephalus species.

Ta_(3)N_(5)/CdS Core–Shell S‑scheme Heterojunction Nanofibers for Efficient Photocatalytic Removal of Antibiotic Tetracycline and Cr(VI):Performance and Mechanism Insights

Ta_(3)N_(5)/CdS core–shell S-scheme heterojunction nanofibers are fabricated by in situ growing CdS nanodots on Ta_(3)N_(5) nanofib-ers via a simple wet-chemical method.These Ta_(3)N_(5)/CdS nanofibers not only affords superior photocatalytic tetracycline degradation and mineralization performance,but also cause an efficient photocatalytic Cr(VI)reduction performance.The creation of favorable core–shell fiber-shaped S-scheme hetero-structure with tightly contacted interface and the maximum interface contact area promises the effective photo-carrier disintegration and the optimal photo-redox capacity synchronously,thus leading to the preeminent photo-redox ability.Some critical environmental factors on the photo-behavior of Ta_(3)N_(5)/CdS are also evaluated in view of the complexity of the authentic aquatic environment.The degradation products of tetracycline were confirmed by HPLC–MS analyses.Furthermore,the effective decline in eco-toxicity of TC intermediates is confirmed by QSAR calculation.This work provides cutting-edge guidelines for the design of high-performance Ta_(3)N_(5)-based S-scheme heterojunction nanofibers for environment restoration.

Novel BiOBr/Bi2S3 high-low junction prepared by molten salt method for boosting photocatalytic degradation and H_(2)O_(2)production

The molten salt method focuses on improving the crystallinity of synthetic materials and avoiding the high energy consumption of traditional synthesis processes.In this work,a novel BiOBr/Bi_(2)S_(3)high-low junction with large contact area was constructed by the molten salt method combined with the ion exchange strategy.Its unique energy band structure and new charge transfer mechanism realize the rapid migration of photogenerated charges between different components.Specifically,Bi_(2)S_(3)was grown on BiOBr in situ by a high-temperature molten salt reaction.Due to the deep valence band position of BiOBr and the narrow band gap of Bi_(2)S_(3),an intrinsic internal electric field and band bending are produced at the interface,forming a high-low junction photocatalyst with an intimate interface.In addition,the BiOBr/Bi_(2)S_(3)composite maintains a high oxidation potential and produces high and robust photocatalytic oxidation activity.In the molten state,the close binding of BiOBr and Bi_(2)S_(3)can be promoted through the ion-exchange strategy,resulting in excellent photocatalytic degradation rates of bisphenol A and tetracycline and in-situ generation of H_(2)O_(2).Finally,the mechanism of carriers separation and transfer in BiOBr/Bi_(2)S_(3)high-low junction is also discussed.Density functional theory(DFT)results found that the improvement of O_(2)adsorption ability would promote the occurrence of oxygen reduction reaction(ORR),and make positive contributions to the enhanced H_(2)O_(2)production activity.This study will provide a new perspective for broadening the spectral response range of Bi-based photocatalytic materials and preparing high-low junction photocatalysts with dense interface by the molten salt method.

Morphological characteristics and DNA barcoding of Pampus echinogaster(Basilewsky, 1855)

The morphological similarities of Pampus fishes have led to considerable confusion in species-level identification,and no accurate information on neotype or DNA barcoding of Pampus echinogaster is available. Two hundred and seven specimens of P. echinogaster were collected from the coastal waters of Dandong, Dongying, Qingdao,Nantong, Zhoushan, Wenzhou, Changle, Taiwan, and Wakayama(Japan), from June 2010 to April 2013. The diagnostic characteristics of P. echinogaster are as follows: dorsal fin VIII-XI-43–51, anal fin V-VIII-43–49, pectoral fin 22–27, caudal fin 19–22, pelvic fin absent; first gill rakers sparse, slender(pointed), 3–4+12–16=15–20; vertebrae39–41; transverse occipital canal on top of head moderately small, wavy ridges not reaching upper origin of pectoral fin; ventral branch of lateral line canal spare, shorter than dorsal branch of lateral line canal. By combining congener sequences of the cytochrome oxidase I(COI) gene from Gen Bank, two absolute groups were detected among all specimens, which further indicated that two valid species were present based on genetic differences in amino acid sequences and the distance between the groups. The sequences of Group 1 can be regarded as DNA barcoding of P. echinogaster. The correct morphological redescription and DNA barcoding of P.echinogaster are presented here to provide a guarantee for efficient and accurate studies, a theoretical basis for classification, and enable appropriate fishery management and conservation strategies for the genus Pampus in the future.

Remarkably Enhanced Photodegradation of Organic Pollutants by NH_(2)-UiO-66/ZnO Composite under Visible-Light Irradiation

Semiconductor photocatalysis is a novel highly efficient and low-cost method for removing organic pollutants from wastewater.However,the photoreduction performance of semiconductors on organic pollutants is limited due to the weak absorption of visible light caused by its wide band gap and low carrier utilization rate resulting from severe electron-holes recombination.In the present study,flower-like NH_(2)-UiO-66(NU66)/ZnO nanocomposites were prepared using a facile method and exhibited high efficiency under visible light driven photocatalysts.The X-ray diffractometer(XRD),scanning electron microscope(SEM),transmitor electron microscope(TEM),and X-ray photoelectron spectroscopy(XPS)were used to characterize the prepared samples,indicating that NU66/ZnO was successfully synthesized.The photocatalytic activity of the prepared NU66/ZnO nanocomposites was determined by measuring the photodegradation of methylene blue(MB)and malachite green(MG)under visible-light irradiation.The optimal nanocomposite loading of 5%wt NU66 to NU66/ZnO demonstrated the highest photocatalytic activity for the degradation of MB.The photocatalytic activity of a 5%NU66/ZnO composite was approximately 95-fold and 19-fold higher than that of NU66 and ZnO samples,respectively.The enhanced activity of the 5%wt NU66/ZnO nanocomposite was further confirmed through photoelectrochemical analysis.The formation of type II heterojunctions between the counterparts significantly suppressed recombination of the photogenerated charge carriers.Photocatalytic degradation experiments with different quenchers indicated that the effect of superoxide anion radicals(•O_(2)^(−))had a greater effect than the other scavengers.Additionally,the improved photocatalytic mechanism underlying the activity of NU66/ZnO nanocomposites was also explored.These findings establish a basis for development of MOF based heterojunction for photocatalytic organic pollution remediation.

Improving performance of ZnO Schottky photodetector by inserting MXenes modified-layer

The development of low-cost and high-performance ZnO Schottky photodetectors (PDs) has drawn intensive attention,but still a challenge due to their poor conductivity and low light utilization efficiency.Here,we introduce Ti_(3)C_(2)T_(X) into ZnO films to fabricate Schottky UV PDs via facile spin-coated method.The fabricated ZnO/Ti_(3)C_(2)T_(X)/ZnO compound film shows outstanding performance on photocurrent,responsivity,noise equivalent power (NEP),normalized detection rate (D~*),and linear dynamic region (LDR),compared with the original Zn O device.The photocurrent is significantly increased by 466%,and the responsivity is improved by one order of magnitude.In addition,it exhibits relatively low NEP (5.99×10^(-11)W),strong D~*(2.53×10~9 Jones),and high LDR (28 dB).The superior performance is ascribed to the enhanced conductivity and light absorption of ZnO film after introduction of Ti_(3)C_(2)T_(X) modification layer,leading to simultaneously faster electron transfer,lower the radiation recombination of electron and holes on the ZnO/Ti_(3)C_(2)T_(X)/ZnO compound film.This work provides a facile way to develop low-cost and highperformance ZnO Schottky PDs.

Nanocoating of CsgA protein for enhanced cell adhesion and proliferation

Immune rejection, poor biocompatibility and cytotoxicity have seriously stalled the widespread application of biometallic materials. To overcome these problems, biometallic materials with fast and sufficient osseointegration, antibacterial properties and long-term stability have attracted the attention of researchers worldwide. Surface modification is currently used as a general strategy to develop material coatings that will overcome these challenging requirements and achieve the successful performance of implants. In this study, we proposed a substrate surface-modification strategy based on biofilm Csg A proteins that promote rapid cell attachment, proliferation, and stabilization of the cytoskeleton. Csg A-based nano-coating is easy to fabricate and has superior performance, which is expected to expand the application of medical implants.

Emerging Bismuth-Based Step-Scheme Heterojunction Photocatalysts for Energy and Environmental Applications

Photocatalysis has been expected to be a promising advanced oxidation process to endlessly convert exhaustless solar energy into storable,transportable,and usable chemical energy.As a kind of visible light-response semiconductors,Bi-based semiconductors can be developed into step-scheme(S-scheme)heterojunction photocatalysts,consisting of a reductive photocatalyst(RP)and an oxidative photocatalyst(OP)with band edge bending.This review sums up the state-of-the-art progress in Bi-based S-scheme heterojunctions,as well as the in-/ex-situ experiments and theoretical calculations to uncover the unique heterostructure and charge transfer mechanism of Bi-based S-scheme heterojunctions in depth.We can find that Bi-based S-scheme heterojunction photocatalysts have advantages in impeding the recombination of photo-induced electron-hole pairs,expediting the charge transfer,broadening solar energy utilization,and maximizing the potential energy of photo-redox reaction sites.Additionally,the recently published work on the potential applications of Bi-based S-scheme heterojunctions is also summarized,including photocatalytic H_(2) production,CO_(2) reduction with water,pollutant degradation,H_(2)O_(2) production,and N_(2) photofixation for ammonia and urea production by comparing and discussing their photocatalytic efficiency.On the basis of research progress,the immediate challenges and future perspectives of Bi-based S-scheme heterojunction photocatalysts are critically debated.

碳量子点/四(4-羧基苯基)卟啉/BiOBr S型异质结用于高效光催化降解抗生素

太阳能光催化处理制药废水是缓解环境问题和能源危机的一种很有前途的方法.然而,提高其处理效率面临众多挑战,如光吸收效率低、光生载流子快速复合和光氧化还原电位低等.本文通过在BiOBr(BOB)微球上沉积碳量子点(CDs)和四(4-羧基苯基)卟啉(TCPP),巧妙地构建了TCPP/CDs/BOB有机/无机三元S型异质结,用于在可见光下有效降解水体中的盐酸四环素(TC).研究发现,由于两者之间的费米能级差异,在形成异质结时触发了电子从TCPP传递到BOB,从而在界面处构建内部电场(IEF).这极大推动了光诱导载流子的有效分离.此外,CDs作为电子收集器进一步提高了S型异质结的载流子分离能力,因此保留了在CDs中聚集更强还原能力的光电子和在BOB价带中更强氧化能力的空穴来参与光催化反应.在这些催化剂中,TCPP/CDs/BOB-2异质结催化剂在40 min内对TC的降解能力高达83.6%.TCPP/CDs/BOB-2的反应速率常数(k)分别约为BOB、CDs/BOB和TCPP/BOB的2.3、1.8和2.0倍.这项工作为探索用于水净化的有机/无机三元S型光催化剂提供了新的视角.

Photoelectrocatalytic hydrogen evolution and synchronous degradation of organic pollutants by pg-C_(3)N_(4)/β-FeOOH S-scheme heterojunction

Crafting photoelectrocatalytic materials with robust oxidation-reduction properties for simultaneous hydrogen evolution and pollutant degradation poses a formidable challenge.In this study,a pg-C_(3)N_(4)/β-FeOOH S-scheme heterostructure with a special energy band structure was developed by anchoring porous pg-C_(3)N_(4)on needle shapedβ-FeOOH.Functioning as a hole extraction layer,needle-leaf-likeβ-FeOOH can facilitate efficient hole migration and enhance charge transport.Remarkably,the optimized 0.2-pg-C_(3)N_(4)/β-FeOOH could degrade 78%of ofloxacin(OFLO)in 90 min.The organic pollutants could absorb a large number of holes,which prompted a greater proportion of photogenerated electrons to actively participate in the hydrogen evolution reaction at the cathode.Consequently,the hydrogen production of 0.2-pg-C_(3)N_(4)/β-FeOOH reached 1452.88μmol cm^(-2)h^(-1),exhibiting a notable increase of 61.81-165.12μmol cm^(-2)h^(-1)compared with that in the absence of pollutants.Experimental and theoretical calculation results underscore that this investigation is grounded in a distinctive electron and hole dual channel transfer mechanism.These findings offer novel insights for the future development of S-scheme heterojunction photoelectrocatalytic materials capable of concurrently degrading pollutants and promoting hydrogen evolution.

Construction of ZnO@CDs@Co_(3)O_(4) sandwich heterostructure with multi-interfacial electron-transfer toward enhanced photocatalytic CO_(2) reduction

Photocatalytic conversion of CO_(2) into small-molecule chemical feedstocks can meet the growing demand for energy and alleviate the global warming. Herein, a p-n ZnO@CDs@Co_(3)O_(4) heterojunction with sandwich structure was constructed by calcination method of self-assembled ZIF-8@CDs@ZIF-67. The ZnO@CDs@Co_(3)O_(4) with well-defined interfacial structure exhibited the significantly enhanced photocatalytic CO_(2) reduction activity, and the optimal catalyst indicated the(CO + CH_(4)) evolution rate of 214.53μmol g^(-1)h^(-1) under simulated solar light, which was superior to ZnO, Co_(3)O_(4) and binary ZnO@Co_(3)O_(4).The internal cavity, exposed active sites, multiple interfaces and constructed p-n heterojunction can facilitate the light harvesting and photoexcited electron transfer. Besides, after introduction of CDs placed in the middle layer between ZnO and Co_(3)O_(4), CDs with excellent photoelectric property further promoted charge separation and migration. This work represents an appealing strategy to construct well-defined photocatalysts for boosting CO_(2) photoreduction.

Rationally designed Ta_(3)N_(5)/BiOCl S-scheme heterojunction with oxygen vacancies for elimination of tetracycline antibiotic and Cr(Ⅵ):Performance,toxicity evaluation and mechanism insight

S-scheme heterojunction photocatalysts have been the“stars”in the field of photocatalysis.Herein,a novel S-scheme heterojunction of Ta_(3)N_(5)/BiOCl with oxygen vacancies(OVs)was fabricated via a facile method.The charge separation and transport mechanism of this Ta_(3)N_(5)/BiOCl S-scheme heterojunction was verified by the analyses of band energy structures,active species,photoelectric behaviors and DFT theoretical calculation.Compared with Ta_(3)N_(5)and BiOCl,the Ta_(3)N_(5)/BiOCl unveils substantially upgraded photocatalytic property under visible light,and the photocatalytic efficiency for removal of tetracycline(TC)and hexavalent chromium(Cr(VI))reaches 89.6%and 91.6%,respectively.The substantial enhancement of the photocatalytic activity is attributed to the synergistic effect of the S-scheme hetero-structure and oxygen vacancies,which improves the visible-light absorption,while promoting the spatial separation of charge carriers with the optimum redox capacity,thereby boosting the production of active species for catalytic reactions.The TC degradation pathway is deduced and the toxicity evolution of TC is appraised using the QSAR method.In a nutshell,this work gives a deep understanding of the photocatalytic mechanism based on Ta_(3)N_(5)/BiOCl as well as presents a newfangled thought for developing highly efficient S-scheme heterojunction photocatalysts for water decontamination.