Integration of morphology and electronic structure modulation on cobalt phosphide nanosheets to boost photocatalytic hydrogen evolution from ammonia borane hydrolysis

The controllable and safe hydrogen storage technologies are widely recognized as the main bottleneck for the accomplishment of sustainable hydrogen energy.Ammonia borane(AB)has regarded as a competitive candidate for chemical hydrogen storage.However,developing efficient yet high-performance catalysts towards hydrogen evolution from AB hydrolysis remains an enormous challenge.Herein,cobalt phosphide nanosheets are synthesized by a facile salt-assisted along with low-temperature phosphidation strategy for simultaneously modulating its morphology and electronic structure,and function as hydrogen evolution photocatalysts.Impressively,the Co_(2)P nanosheets display extraordinary performance with a record high turnover frequency of 44.9 min^(-1),outperforming most of the noble-metal-free catalysts reported to date.This remarkable performance is attributed to its desired nanosheets structure,featuring with high specific surface area,abundant exposed active sites,and short charge diffusion paths.Our findings provide a novel strategy for regulating metal phosphides with desired phase structure and morphology for energy-related applications and beyond.

Engineering of oxygen vacancy and bismuth cluster assisted ultrathin Bi_(12)O_(17)Cl_(2)nanosheets with efficient and selective photoreduction of CO_(2)to CO

The photocatalytic conversion of CO_(2)into solar‐powered fuels is viewed as a forward‐looking strategy to address energy scarcity and global warming.This work demonstrated the selective photoreduction of CO_(2)to CO using ultrathin Bi_(12)O_(17)Cl_(2)nanosheets decorated with hydrothermally synthesized bismuth clusters and oxygen vacancies(OVs).The characterizations revealed that the coexistences of OVs and Bi clusters generated in situ contributed to the high efficiency of CO_(2)–CO conversion(64.3μmol g^(−1)h^(−1))and perfect selectivity.The OVs on the facet(001)of the ultrathin Bi_(12)O_(17)Cl_(2)nanosheets serve as sites for CO_(2)adsorption and activation sites,capturing photoexcited electrons and prolonging light absorption due to defect states.In addition,the Bi‐cluster generated in situ offers the ability to trap holes and the surface plasmonic resonance effect.This study offers great potential for the construction of semiconductor hybrids as multiphotocatalysts,capable of being used for the elimination and conversion of CO_(2)in terms of energy and environment.

The potassium storage performance of carbon nanosheets derived from heavy oils

As by-products of petroleum refining,heavy oils are characterized by a high carbon content,low cost and great variability,making them competitive precursors for the anodes of potassium ion batteries(PIBs).However,the relationship between heavy oil composition and potassium storage performance remains unclear.Using heavy oils containing distinct chemical groups as the carbon source,namely fluid catalytic cracking slurry(FCCS),petroleum asphalt(PA)and deoiled asphalt(DOA),three carbon nanosheets(CNS)were prepared through a molten salt method,and used as the anodes for PIBs.The composition of the heavy oil determines the lamellar thicknesses,sp3-C/sp2-C ratio and defect concentration,thereby affecting the potassium storage performance.The high content of aromatic hydrocarbons and moderate amount of heavy component moieties in FCCS produce carbon nanosheets(CNS-FCCS)that have a smaller layer thickness,larger interlayer spacing(0.372 nm),and increased number of folds than in CNS derived from the other three precursors.These features give it faster charge/ion transfer,more potassium storage sites and better reaction kinetics.CNS-FCCS has a remarkable K^(+)storage capacity(248.7 mAh g^(-1) after 100 cycles at 0.1 A g^(-1)),long cycle lifespan(190.8 mAh g^(-1) after 800 cycles at 1.0 A g^(-1))and excellent rate capability,ranking it among the best materials for this application.This work sheds light on the influence of heavy oil composition on carbon structure and electrochemical performance,and provides guidance for the design and development of advanced heavy oil-derived carbon electrodes for PIBs.

Flame-assisted ultrafast synthesis of functionalized carbon nanosheets for high-performance sodium storage

The unique structural features of hard carbon(HC)make it a promising anode candidate for sodium-ion batteries(SIB).However,traditional methods of preparing HC require special equipment,long reaction times,and large energy consumption,resulting in low throughputs and efficiency.In our contribution,a novel synthesis method is proposed,involving the formation of HC nanosheets(NS-CNs)within minutes by creating an anoxic environment through flame combustion and further introducing sulfur and nitrogen sources to achieve heteroatom doping.The effect of heterogeneous element doping on the microstructure of HC is quantitatively analyzed by high-resolution transmission electron microscopy and image processing technology.Combined with density functional theory calculation,it is verified that the functionalized HC exhibits stronger Na^(+)adsorption ability,electron gain ability,and Na^(+) migration ability.As a result,NS-CNs as SIB anodes provide an ultrahigh reversible capacity of 542.7mAh g^(-1) at 0.1Ag^(-1),and excellent rate performance with a reversible capacity of 236.4mAh g^(-1) at 2Ag^(-1) after 1200 cycles.Furthermore,full cell assembled with NS-CNs as the can present 230mAh g^(-1) at 0.5Ag^(-1) after 150 cycles.Finally,in/ex situ techniques confirm that the excellent sodium storage properties of NS-CNs are due to the construction of abundant active sites based on the novel synthesis method for realizing the reversible adsorption of Na^(+).This work provides a novel strategy to develop novel carbons and gives deep insights for the further investigation of facile preparation methods to develop high-performance carbon anodes for alkali-ion batteries.

Modified electronic structure and enhanced hydroxyl adsorption make quaternary Pt-based nanosheets efficient anode electrocatalysts for formic acid-/alcohol-air fuel cells

Surface/interface engineering of a multimetallic nanostructure with diverse electrocatalytic properties for direct liquid fuel cells is desirable yet challenging.Herein,using visible light,a class of quaternary Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)ultrathin nanosheets is fabricated and used as high-performance anode electrocatalysts for formic acid-/alcohol-air fuel cells.The modified electronic structure of Pt,enhanced hydroxyl adsorption,and abundant exterior defects afford Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C high intrinsic anodic electrocatalytic activity to boost the power densities of direct formic acid-/methanol-/ethanol-/ethylene glycol-/glycerol-air fuel cells,and the corresponding peak power density of Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C is respectively 129.7,142.3,105.4,124.3,and 128.0 mW cm^(-2),considerably outperforming Pt/C.Operando in situ Fourier transform infrared reflection spectroscopy reveals that formic acid oxidation on Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C occurs via a CO_(2)-free direct pathway.Density functional theory calculations show that the presence of Ag,Bi,and Te in Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)suppresses CO^(*)formation while optimizing dehydrogenation steps and synergistic effect and modified Pt effectively enhance H_(2)O dissociation to improve electrocatalytic performance.This synthesis strategy can be extended to 43 other types of ultrathin multimetallic nanosheets(from ternary to octonary nanosheets),and efficiently capture precious metals(i.e.,Pd,Pt,Rh,Ru,Au,and Ag)from different water sources.

Boosting the catalytic activity toward oxygen reduction via a heterostructure of porous iron oxide-decorated 2D NiO/NG nanosheets

As a noble metal substitute,two-dimensional(2D)hierarchical nano-frame structures have attracted great interest as candidate catalysts due to their remarkable advantages-high intrinsic activity,high electron mobility,and straightforward surface functionalization.Therefore,they may replace Pt-based catalysts in oxygen reduction reaction(ORR)applications.Herein,a simple method is developed to design hierarchical nano-frame structures assembled via 2D NiO and N-doped graphene(NG)nanosheets.This procedure can yield nanostructures that satisfy the criteria correlated with improved electrocatalytic performance,such as large surface area,numerous undercoordinated atoms,and high defect densities.Further,porous NG nanosheet architectures,featuring NiO nanosheets densely coordinated with accessible holey Fe_(2)O_(3) moieties,can enhance mesoporosity and balance hydrophilicity.Such improvements can facilitate charge transport and expose formerly inaccessible reaction sites,maximizing active site density utilization.Density functional theory(DFT)calculations reveal favored O_(2) adsorption and dissociation on Fe_(2)O_(3) hybrid structures when supported by 2D NiO and NG nanomaterials,given 2D materials donated charge to Fe_(2)O_(3) active sites.Our systematic studies reveal that synergistic contributions are responsible for enriching the catalytic activity of Fe_(2)O_(3)@NiO/NG in alkaline media-encompassing internal voids and pores,unique hierarchical support structures,and concentrated N-dopant and bimetallic atomic interactions.Ultimately,this work expands the toolbox for designing and synthesizing highly efficient 2D/2D shelled functional nanomaterials with transition metals,endeavoring to benefit energy conversion and related ORR applications.

Room Temperature Synthesis of Vertically Aligned Amorphous Ultrathin NiCo-LDH Nanosheets Bifunctional Flexible Supercapacitor Electrodes

Developing a simple scalable method to fabricate electrodes with high capacity and wide voltage range is desired for the real use of electrochemical supercapacitors.Herein,we synthesized amorphous NiCo-LDH nanosheets vertically aligned on activated carbon cloth substrate,which was in situ transformed from Co-metal-organic framework materials nano-columns by a simple ion exchange process at room temperature.Due to the amorphous and vertically aligned ultrathin structure of NiCo-LDH,the NiCo-LDH/activated carbon cloth composites present high areal capacities of 3770 and 1480 mF cm^(-2)as cathode and anode at 2 mA cm^(-2),and 79.5%and 80%capacity have been preserved at 50 mA cm^(-2).In the meantime,they all showed excellent cycling performance with negligible change after>10000 cycles.By fabricating them into an asymmetric supercapacitor,the device achieves high energy densities(5.61 mWh cm^(-2)and 0.352 mW cm^(-3)).This work provides an innovative strategy for simplifying the design of supercapacitors as well as providing a new understanding of improving the rate capabilities/cycling stability of NiCo-LDH materials.

Ultraviolet Photodetector based on Sr_(2)Nb_(3)O_(10) Perovskite Nanosheets

Liquid-phase exfoliation was employed to synthesize Sr_(2)Nb_(3)O_(10) perovskite nanosheets with thicknesses down to 1.76 nm.Transmission electron microscopy(TEM),atomic force microscope(AFM),X-ray photoelectron spectrometer(XPS),and other characterization techniques were used to evaluate the atomic structure and chemical composition of the exfoliated nanosheets.A UV photodetector based on individual Sr_(2)Nb_(3)O_(10) nanosheets was prepared to demonstrate the application of an ultraviolet(UV) photodetector.The UV photodetector exhibited outstanding photocurrent and responsivity with a responsivity of 3×10^(5) A·W^(-1) at 5 V bias under 280 nm illumination,a photocurrent of 60 nA,and an on/off ratio of 3×10^(2).

Strongly Coupled Ag/Sn-SnO_(2)Nanosheets Toward CO_(2)Electroreduction to Pure HCOOH Solutions at Ampere‑Level Current

Electrocatalytic reduction of CO_(2) converts intermittent renewable electricity into value-added liquid products with an enticing prospect,but its practical application is hampered due to the lack of high-performance electrocatalysts.Herein,we elaborately design and develop strongly coupled nanosheets composed of Ag nanoparticles and Sn-SnO_(2) grains,designated as Ag/Sn-SnO_(2) nanosheets(NSs),which possess optimized electronic structure,high electrical conductivity,and more accessible sites.As a result,such a catalyst exhibits unprecedented catalytic performance toward CO_(2)-to-formate conversion with near-unity faradaic efficiency(≥90%),ultrahigh partial current density(2,000 mA cm^(−2)),and superior long-term stability(200 mA cm^(−2),200 h),surpassing the reported catalysts of CO_(2) electroreduction to formate.Additionally,in situ attenuated total reflection-infrared spectra combined with theoretical calculations revealed that electron-enriched Sn sites on Ag/Sn-SnO_(2)NSs not only promote the formation of*OCHO and alleviate the energy barriers of*OCHO to*HCOOH,but also impede the desorption of H*.Notably,the Ag/Sn-SnO_(2)NSs as the cathode in a membrane electrode assembly with porous solid electrolyte layer reactor can continuously produce~0.12 M pure HCOOH solution at 100 mA cm^(−2)over 200 h.This work may inspire further development of advanced electrocatalysts and innovative device systems for promoting practical application of producing liquid fuels from CO_(2).

Plasma-assisted synthesis of porous bismuth nanosheets for electrocatalytic CO_(2)-to-formate reduction

The electrochemical carbon dioxide reduction(eCO_(2)RR)to formate,driven by clean energy,is a promising approach for producing renewable chemicals and high-value fuels.Despite its potential,further development faces challenges due to limitations in electrocatalytic activity and durability,especially for nonnoble metal-based catalysts.Here,naturally abundant bismuth-based nanosheets that can effectively drive CO_(2)-to-formate electrocatalytic reduction are prepared using the plasma-activated Bi_(2)Se_(3) followed by a reduction process.Thus-obtained plasma-activated Bi nanosheets(P-BiNS)feature ultrathin structures and high surface areas.Such nanostructures ensure the P-BiNS with outstanding eCO_(2)RR catalytic performance,highlighted by the current density of over 80 mA cm^(-2) and a formate Faradic efficiency of>90%.Furthermore,P-BiNS catalysts demonstrate excellent durability and stability without deactivation following over 50h of operation.The selectivity for formate production is also studied by density functional theory(DFT)calculations,validating the importance and efficacy of the stabilization of intermediates(^(*)OCHO)on the P-BiNS surfaces.This study provides a facile plasma-assisted approach for developing high-performance and low-cost electrocatalysts.

High-throughput calculation-based rational design of Fe-doped MoS_(2) nanosheets for electrocatalytic p H-universal overall water splitting

Electrocatalytic water splitting is crucial for H2generation via hydrogen evolution reaction(HER)but subject to the sluggish dynamics of oxygen evolution reaction(OER).In this work,single Fe atomdoped MoS_(2)nanosheets(SFe-DMNs)were prepared based on the high-throughput density functional theory(DFT)calculation screening.Due to the synergistic effect between Fe atom and MoS_(2)and optimized intermediate binding energy,the SFe-DMNs could deliver outstanding activity for both HER and OER.When assembled into a two-electrode electrolytic cell,the SFe-DMNs could achieve the current density of 50 mA cm^(-2)at a low cell voltage of 1.55 V under neutral condition.These results not only confirmed the effectiveness of high-throughput screening,but also revealed the excellent activity and thus the potential applications in fuel cells of SFe-DMNs.

Heterointerface engineering of rhombic Rh nanosheets confined on MXene for efficient methanol oxidation

Although metallic rhodium(Rh)is regarded as a promising platinum-alternative anode catalyst of direct methanol fuel cell(DMFC),the conventional"particle-to-face"contact model between Rh and matrix largely limits the overall electrocatalytic performance due to their insufficient cooperative effects.Herein,we report a controllable and robust heterointerface engineering strategy for the bottom-up fabrication of rhombic Rh nanosheets in situ confined on Ti_3C_(2)T_x MXene nanolamellas(Rh NS/MXene)via a convenient stereoassembly process.This unique design concept gives the resulting 2D/2D Rh NS/MXene heterostructure intriguing textural features,including large accessible surface areas,strong"face-toface"interfacial interactions,homogeneous Rh nanosheet distribution,ameliorative electronic structure,and high electronic conductivity.As a consequence,the as-prepared Rh NS/MXene nanoarchitectures exhibit exceptional electrocatalytic methanol oxidation properties in terms of a large electrochemically active surface area of 126.2 m~2 g_(Rh)~(-1),a high mass activity of 1056.9 mA mg_(Rh)-~1,and a long service life,which significantly outperform those of conventional particle-shaped Rh catalysts supported by carbon black,carbon nanotubes,reduced graphene oxide,and MXene matrixes as well as the commercial Pt nanoparticle/carbon black and Pd nanoparticle/carbon black catalysts with the same noble metal loading amount.Density functional theory calculations further demonstrate that the direct electronic interaction at the well-contacted 2D/2D heterointerfaces effectively enhances the adsorption energy of Rh nanosheets and induces a left shift of the d-band center,thereby making the Rh NS/MXene configuration suffer less from CO poisoning.This work highlights the importance of rational heterointerface design in the construction of advanced noble metal/MXene electrocatalysts,which may provide new avenues for developing the next-generation DMFC devices.

Composite polymer electrolyte reinforced by graphitic carbon nitride nanosheets for room-temperature all-solid-state lithium batteries

By virtue of the flexibility and safety, polyethylene oxide(PEO) based electrolytes are regarded as an appealing candidate for all-solid-state lithium batteries. However, their application is limited by the poor ionic conductivity at room temperature, narrow electrochemical stability window and uncontrolled growth of lithium dendrite. To alleviate these problems, we introduce the ultrathin graphitic carbon nitride nanosheets(GCN) as advanced nanofillers into PEO based electrolytes(GCN-CPE). Benefiting from the high surface area and abundant surface N-active sites of GCN, the GCN-CPE displays decreased crystallinity and enhanced ionic conductivity. Meanwhile, Fourier transform infrared and chronoamperometry studies indicate that GCN can facilitate Li+migration in the composite electrolyte. Additionally, the GCN-CPE displays an extended electrochemical window compared with PEO based electrolytes. As a result, Li symmetric battery assembled with GCN-CPE shows a stable Li plating/stripping cycling performance, and the all-solid-state Li/LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622) batteries using GCN-CPE exhibit satisfactory cyclability and rate capability in a voltage range of 3-4.2 V at 30 ℃.

The enhancement of performance and imbibition effect of slickwater-based fracturing fluid by using MoS_(2)nanosheets

Slickwater-based fracturing fluid has recently garnered significant attention as the major fluid for volumetric fracturing;however,lots of challenges and limitations such as low viscosity,poor salt tolerance,and possible formation damage hinder the application of the conventional simple slickwater-based fracturing fluid.In addition,nanomaterials have proven to be potential solutions or improvements to a number of challenges associated with the slickwater.In this paper,molybdenum disulfide(MoS_(2))nanosheets were chemically synthesized by hydrothermal method and applied to improve the performance of conventional slickwater-based fracturing fluid.Firstly,the microstructure characteristics and crystal type of the MoS_(2)nanosheets were analyzed by SEM,EDS,TEM,XPS,and Raman spectroscopy techniques.Then,a series of evaluation experiments were carried out to compare the performance of MoS_(2)nanosheet-modified slickwater with the conventional slickwater,including rheology,drag reduction,and sand suspension.Finally,the enhanced imbibition capacity and potential mechanism of the nanosheet-modified slickwater were systematically investigated.The results showed that the self-synthesized MoS_(2)nanosheets displayed a distinct ultrathin flake-like morphology and a lateral size in the range of tens of nanometers.In the nano-composites,each MoS_(2)nanosheet plays the role of cross-linking point,so as to make the spatial structure of the entire system more compact.Moreover,nanosheet-modified slickwater demonstrates more excellent properties in rheology,drag reduction,and sand suspension.The nanosheet-modified slickwater has a higher apparent viscosity after shearing 120 min under 90℃ and 170 s^(−1).The maximum drag reduction rate achieved 76.3%at 20℃,and the sand settling time of proppants with different mesh in the nano-composites was prolonged.Spontaneous imbibition experiments showed that the gel-breaking fluid of nanosheet-modified slickwater exhibited excellent capability of oil-detaching,and increase the oil recovery to∼35.43%.By observing and analyzing the interfacial behavior of MoS_(2)nanosheets under stimulated reservoir conditions,it was found that the presence of an interfacial tension gradient and the formation of a climbing film may play an essential role in the spontaneous imbibition mechanism.This work innovatively uses two-dimensional MoS_(2)nanosheets to modify regular slickwater and confirms the feasibility of flake-like nanomaterials to improve the performance of slickwater.The study also reveals the underlying mechanism of enhanced imbibition efficiency of the nano-composites.

Co-Ru alloy nanoparticles decorated onto two-dimensional nitrogen doped carbon nanosheets towards hydrogen/oxygen evolution reaction and oxygen reduction reaction

Constructing highly-efficient electrocatalysts toward hydrogen evolution reaction(HER)/oxygen evolution reaction(OER)/oxygen reduction reaction(ORR)with excellent stability is quite important for the development of renewable energy-related applications.Herein,Co-Ru based compounds supported on nitrogen doped two-dimensional(2D)carbon nanosheets(NCN)are developed via one step pyrolysis procedure(Co-Ru/NCN)for HER/ORR and following low-temperature oxidation process(Co-Ru@RuO_(x)/NCN)for OER.The specific 2D morphology guarantees abundant active sites exposure.Furthermore,the synergistic effects arising from the interaction between Co and Ru are crucial in enhancing the catalytic performance.Thus,the resulting Co-Ru/NCN shows remarkable electrocatalytic performance for HER(70 mV at 10 mA cm^(-2))in 1 M KOH and ORR(half-wave potential E_(1/2)=0.81 V)in 0.1 M KOH.Especially,the Co-Ru@RuO_(x)/NCN obtained by oxidation exhibits splendid OER performance in both acid(230 mV at 10 mA cm^(-2))and alkaline media(270 mV at 10 mA cm^(-2))coupled with excellent stability.Consequently,the fabricated two-electrode water-splitting device exhibits excellent performance in both acidic and alkaline environments.This research provides a promising avenue for the advancement of multifunctional nanomaterials.

Unraveling the Role of Nitrogen-Doped Carbon Nanowires Incorporated with MnO_(2)Nanosheets as High Performance Cathode for Zinc-Ion Batteries

Manganese-based cathode materials are considered as a promising candidate for rechargeable aqueous zinc-ion batteries(ZIBs).Suffering from poor conductive and limited structure tolerance,various carbon matrix,especially N-doped carbon,were employed to incorporate with MnO_(2)for greatly promoted electrochemical performances.However,the related underlying mechanism is still unknown,which is unfavorable to guide the design of high performance electrode.Herein,by incorporating layered MnO_(2)with N-doped carbon nanowires,a free-standing cathode with hierarchical core-shell structure(denoted as MnO_(2)@NC)is prepared.Benefiting from the N-doped carbon and rational architecture,the MnO_(2)@NC electrode shows an enhanced specific capacity(325 mAh g^(−1)at 0.1 A g^(−1))and rate performance(90 mAh g^(−1)at 2 A g^(−1)),as well as improved cycling stability.Furthermore,the performance improvement mechanism of MnO_(2)incorporated by N-doped carbon is investigated by X-ray photoelectron spectroscopy(XPS),Raman spectrums and density functional theory(DFT)calculation.The N atom elongates the Mn-O bond and reduces the valence of Mn^(4+)ion in MnO_(2)crystal by delocalizing its electron clouds.Thus,the electrostatic repulsion will be weakened when Zn^(2+)/H^(+)insert into the host MnO_(2)lattices,which is profitable to more cation insertion and faster ion transfer kinetics for higher capacity and rate capability.This work elucidates a fundamental understanding of the functions of N-doped carbon in composite materials and shed light on a practical pathway to optimize other electrode materials.

Electrodeposited 3D hierarchical NiFe microflowers assembled from nanosheets robust for the selective electrooxidation of furfuryl alcohol

A robust and green strategy for the selective upgrading of biomass-derived platform chemicals towards highly valuable products is important for the sustainable development.Herein,the efficient electrocatalytic oxidation of biomass-derived furfuryl alcohol(FFA)into furoic acid(FurAc)catalyzed by the electrodeposited non-precious NiFe microflowers was successfully reached under the low temperature and ambient pressure.The 3D hierarchical NiFe microflowers assembled from ultrathin nanosheets were controllably synthesized by the electrodeposition method and uniformly grown on carbon fiber paper(CFP).Electrochemical analysis confirmed that NiFe nanosheets more preferred in the selective oxidation of FFA(FFAOR)than oxygen evolution reaction(OER).The linear sweep voltammetry(LSV)in FFAOR displayed a clear decrease towards lower potential,resulting in 30 mV reduction of overpotential at 20 mA cm^(-2) compared with that of OER.The optimal catalyst Ni_(1)Fe_(2) nanosheets exhibited the highest selectivity of FurAc(94.0%)and 81.4%conversion of FFA within 3 h.Besides,the influence of various reaction parameters on FFAOR was then explored in details.After that,the reaction pathway was investigated and rationally proposed.The outstanding performance for FFAOR can be ascribed to the unique structure of 3D flower-like NiFe nanosheets and oxygen vacancies,resulting in large exposure of active sites,faster electron transfer and enhanced adsorption of reactants.Our findings highlight a facile and convenient mean with a promising green future,which is promising for processing of various biomass-derived platform chemicals into value-added products.

Highly Selective Electrocatalytic CuEDTA Reduction by MoS_(2) Nanosheets for Efficient Pollutant Removal and Simultaneous Electric Power Output

Electrocatalytic reduction of ethylenediamine tetraacetic acid copper(CuEDTA),a typical refractory heavy metal complexation pollutant,is an environmental benign method that operates at mild condition.Unfortunately,the selective reduction of CuEDTA is still a big challenge in cathodic process.In this work,we report a MoS_(2) nanosheet/graphite felt(GF)cathode,which achieves an average Faraday efficiency of 29.6%and specific removal rate(SRR)of 0.042 mol/cm^(2)/h for CuEDTA at−0.65 V vs SCE(saturated calomel electrode),both of which are much higher than those of the commonly reported electrooxidation technology-based removal systems.Moreover,a proofof-concept CuEDTA/Zn battery with Zn anode and MoS_(2)/GF cathode is demonstrated,which has bifunctions of simultaneous CuEDTA removal and energy output.This is one of the pioneer studies on the electrocatalytic reduction of heavy metal complex and CuEDTA/Zn battery,which brings new insights in developing efficient electrocatalytic reduction system for pollution control and energy output.

Achieving highly selective electrochemical CO_(2) reduction to C_(2)H_(4) on Cu nanosheets

The conversion of CO_(2)into value-added chemicals coupled with the storage of intermittent renewable electricity is attractive.CuO nanosheets with an average size and thickness of~30 and~20 nm have been developed,which are in situ reduced into Cu nanosheets during electrochemical CO_(2)reduction reaction(ECO_(2)RR).The derived Cu nanosheets demonstrate much higher selectivity for C2H4production than commercial CuO derived Cu powder,with an optimum Faradaic efficiency of 56.2%and a partial current density of C_(2)H_(4)as large as 171.0 mA cm^(-2)in a gas diffusion flow cell.The operando attenuated total reflectance-Fourier transform infrared spectra measurements and density functional theory simulations illustrate that the high activity and selectivity of Cu nanosheets originate from the edge sites on Cu nanosheets with a coordinate number around 5(4–6),which facilitates the formation of^(*)CHO rather than^(*)COH intermediate,meanwhile boosting the C-C coupling reaction of^(*)CO and^(*)CHO intermediates,which are the critical steps for C_(2)H_(4)formation.

Thermal decomposition effect of MgCo_(2)O_(4)nanosheets on ammonium perchlorate-based energetic molecular perovskites

Energetic molecular perovskites have attracted widespread attention in the fields of energy materials due to their high detonation performance.In this work,we reported the effect of MgCo_(2)O_(4) nanosheets on the thermal decomposition of ammonium perchlorate(NH_(4)ClO_(4),AP)-based energetic molecular perovskites(AP-based energetic molecular perovskites).The morphology and structure of the MgCo_(2)O_(4) nanosheets were characterized.And their catalytic effect on the thermal decomposition of AP-based energetic molecular perovskites(H_2pz)[NH_(4)(ClO_(4))_(3)](PAP-4),(H_2dabco)[NH_(4)(ClO_(4))_(3)](DAP-4),(H_2mpz)[NH_(4)(ClO_(4))_(3)](PAP-M_(4)),and (H_2hpz)[NH_(4)(ClO_(4))_(3)](PAP-H_(4)) was analyzed.The results showed that MgCo_(2)O_(4) nanosheets had excellent intrinsically catalytic performance towards enhancing the thermal decomposition of AP-based energetic molecular perovskites.After adding MgCo_(2)O_(4) nanosheets,the thermal decomposition peak temperatures of PAP-4,DAP-4,PAP-M_(4),and PAP-H_(4) had been reduced by35.7℃,48.4℃,37.9℃,and 43.6℃,respectively.And the activation energy(Ea)of the thermal decomposition of AP-based energetic molecular perovskites had been reduced,the Eaof PAP-H_(4) decreased by 46.4 kJ/mol at most among them.The catalytic mechanism of MgCo_(2)O_(4) nanosheets for AP-based energetic molecular perovskites is analyzed.This work provides a reference for the future application of AP-based energetic molecular perovskites.