Herein,we have designed a highly active and robust trifunctional electrocatalyst derived from Prussian blue analogs,where Co_(4)N nanoparticles are encapsulated by Fe embedded in N-doped carbon nanocubes to synthesize...Herein,we have designed a highly active and robust trifunctional electrocatalyst derived from Prussian blue analogs,where Co_(4)N nanoparticles are encapsulated by Fe embedded in N-doped carbon nanocubes to synthesize hierarchically structured Co_(4)N@Fe/N-C for rechargeable zinc-air batteries and overall water-splitting electrolyzers.As confirmed by theoretical and experimental results,the high intrinsic oxygen reduction reaction,oxygen evolution reaction,and hydrogen evolution reaction activities of Co_(4)N@Fe/N-C were attributed to the formation of the heterointerface and the modulated local electronic structure.Moreover,Co_(4)N@Fe/N-C induced improvement in these trifunctional electrocatalytic activities owing to the hierarchical hollow nanocube structure,uniform distribution of Co_(4)N,and conductive encapsulation by Fe/N-C.Thus,the rechargeable zinc-air battery with Co_(4)N@Fe/N-C delivers a high specific capacity of 789.9 mAh g^(-1) and stable voltage profiles over 500 cycles.Furthermore,the overall water electrolyzer with Co_(4)N@Fe/N-C achieved better durability and rate performance than that with the Pt/C and IrO2 catalysts,delivering a high Faradaic efficiency of 96.4%.Along with the great potential of the integrated water electrolyzer powered by a zinc-air battery for practical applications,therefore,the mechanistic understanding and active site identification provide valuable insights into the rational design of advanced multifunctional electrocatalysts for energy storage and conversion.展开更多
Development of high-efficiency non-noble electrocatalysts for oxygen reduction reaction(ORR),oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is urgently needed for high-performance Zn-air batteries a...Development of high-efficiency non-noble electrocatalysts for oxygen reduction reaction(ORR),oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is urgently needed for high-performance Zn-air batteries and overall water splitting.Here,a facile strategy to synthesize novel Co-MOF,O-doped carbon(Co-MOF-T)based on Zn,Co-doped glucosamine and ZIF-8 by pyrolysis at temperature T was demonstrated.The prepared Co-MOF-800 showed a superior oxygen reduction reaction(ORR)activity comparable to that of commercial Pt/C catalyst.In addition,this catalyst shows great potential in the overall water splitting due to the excellent oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)activities.Based on the trifunctional activity,the primary Zn-air batteries using a Co-MOF-800 air electrode achieved a high open-circuit voltage of 1.38 V,a specific capacity of 671.6 mAh g^(-1) Zn,and a prominent peak power density of 144 mW cm^(-2).Also,the rechargeable Zn-air batteries based on CoMOF-800 air electrode could be smoothly run for 510 cycles with a low voltage gap of 0.58 V.Finally,the trifunctional Co-MOF-800 catalyst was applied to boost the electrochemical water splitting,demonstrating its promising potential as a green energy material for practical applications.展开更多
To meet the practical demand of wearable/portable electronics, developing high-efficiency and durable multifunctional catalyst and in-situ assembling catalysts into electrodes with flexible features are urgently neede...To meet the practical demand of wearable/portable electronics, developing high-efficiency and durable multifunctional catalyst and in-situ assembling catalysts into electrodes with flexible features are urgently needed but challenging. Herein, we report a simple route to fabricate bendable multifunctional electrodes by in-situ carbonization of metal ion absorbed polyaniline precursor. Alloy nanoparticles encapsulated in graphite layer are uniformly distributed in the N-doping carbon nanorod skeleton. Profiting from the favorable free-standing structure and the cooperative effect of metallic nanoparticles, graphitic layer and N doped-carbon architecture, the trifunctional electrodes exhibit prominent activities and stability toward HER, OER and ORR. Notably, due to the protection of carbon layer, the electrocatalysts show the reversible catalytic HER/OER properties. The overall water splitting device can continuously work for 12 h under frequent exchanges of cathode and anode. Importantly, the bendable metal air batteries fabricated by self-supported electrode not only displays the outstanding battery performance,achieving a decent peak power density(125 mW cm^(-2)) and exhibiting favorable charge-discharge durability of 22 h, but also holds superb flexible stability. Specially, a lightweight self-driven water splitting unit is demonstrated with stable hydrogen production.展开更多
The development of single electrode with multifunctional purposes for electrochemical devices remains a symbolic challenge in recent technology.This work explores interfacially-rich transition metal nitride hybrid tha...The development of single electrode with multifunctional purposes for electrochemical devices remains a symbolic challenge in recent technology.This work explores interfacially-rich transition metal nitride hybrid that consist of nickel nitride and vanadium oxynitride(VO_(0.26)N_(0.52))on robust carbon fiber(denoted CF/Ni_(3)N/VON)as trifunctional electrode for hydrogen evolution reaction(HER),oxygen evolution reaction(OER),and sodium ion batteries(SIBs).The as-prepared CF/Ni_(3)N/VON exhibits low HER overpotential of 48 m V@10 m A cm^(-2),OER overpotential of 287 m V@10 m A cm^(-2),and sodium-ion anode storage reversible capacity of 555 m A h g^(-1)@0.2 C.Theoretical analyses reveal that the Ni_(3)N effectively facilitates hydrogen desorption for HER,increases the electrical conductivity for OER,and promotes the Na-ion storage intercalation process,while the VON substantially elevates the water dissociation kinetics for HER,accelerates the adsorption of OH*intermediate for OER and enhances the Na-ion surface adsorption storage process.Owing to the excellent HER and OER performances of the CF/Ni_(3)N/VON electrode,an overall water splitting device denoted as CF/Ni_(3)N/VON//CF/Ni_(3)N/VON was not only assembled showing an operating voltage of 1.63 V at current density of 10 m A cm^(-2)but was also successfully self-powered by the assembled CF/Ni_(3)N/VON//CF/Na_(3)V_(2)(PO_(4))_(3) flexible sodium ion battery.This work will contribute to the development of efficient and cost-effective flexible integrated electrochemical energy devices.展开更多
Hydrolytic polymerization of 8 - caprolactam is carried out by the use of trimesinic acid as molecular weight controlling agent, and polyamide 6 with three branched chains is obtained. The initial concentrations of re...Hydrolytic polymerization of 8 - caprolactam is carried out by the use of trimesinic acid as molecular weight controlling agent, and polyamide 6 with three branched chains is obtained. The initial concentrations of regulators almost have no effect on the conversion of caprolactam , while relative viscosity of the polymer is affected by the concentrations. DSC investigation shows that DSC curve changes from single peak for regular polyamide 6 to one peak with one shoulder or one small peak for polyamide 6 with three branched chains and the melting point decreases with the increase of the amount of trimesinic acid. In addition, the concentration of trimesinic acid being the same, DSC curves change from almost sharp single peak to double peak with increasing reaction time.展开更多
The development of robust and efficient trifunctional catalysts showing excellent oxygen evolution reaction(OER), oxygen reduction reaction(ORR) and hydrogen evolution reaction(HER) kinetics has been challenging.Herei...The development of robust and efficient trifunctional catalysts showing excellent oxygen evolution reaction(OER), oxygen reduction reaction(ORR) and hydrogen evolution reaction(HER) kinetics has been challenging.Herein, we prepared a hybrid iron and cobalt-based metal alloy phosphide on a phosphorus and nitrogen co-doped carbon substrate(Fe Co-P/PNC) as a catalyst using a one-step Pregulation method. The catalyst exhibited a positive half-wave potential of 0.86 V versus the reversible hydrogen electrode(RHE) for ORR, and low overpotentials of 350 and 158 m V for OER and HER, respectively, to achieve a current density of10 m A cm^(-2). Density functional theory calculations demonstrated the dominant role of P in both Fe Co phosphide and carbon matrix, which led to the good ORR, OER and HER kinetics. The assembled aqueous and flexible Zn-air batteries with Fe Co-P/PNC as the air cathode displayed excellent peak power densities of 195.1 and 90.8 m W cm^(-2), respectively, as well as outstanding charging-discharging performance, long lifetime, and high flexibility. Moreover, the self-powered overall water-splitting cell exhibited a low working voltage of1.71 V to achieve a current density of 10 m A cm^(-2), confirming its excellent multifunctional OER/ORR/HER activity.展开更多
Rational design of highly efficient,robust and nonprecious electrocatalysts for the oxygen reduction reaction(ORR),oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is highly demanded and challenging.H...Rational design of highly efficient,robust and nonprecious electrocatalysts for the oxygen reduction reaction(ORR),oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is highly demanded and challenging.Here,heterostructural Co_(3O)_(4)@Ni_(2)P arrays with numerous reaction sites,unique interfacial electronic structure and fast charge transfer kinetics are developed as electrocatalysts for rechargeable Zn-air batteries and overall water splitting.Both density functional theory calculation and X-ray absorption fine structure analysis manifest that the synergistic structural and abundant electronic modulations interfaces are formed,thus simultaneously promoting the electrocatalytic kinetics,activities and stabilities.Specifically,it can achieve an ultralow overpotential of 270 m V and 28 m V at 10 m A cm^(-2) for OER and HER,respectively.The water electrolyzer delivers a current density of 10 m A cm^(-2) at 1.563 V;furthermore,rechargeable Zn-air batteries triggered by this heterostructure can achieve excellent cyclic stability of 177 h(2 h per cycle)at 10 m A cm^(-2);both devices are superior to the Pt/C+Ir/C.This work not only designs an efficient trifunctional electrocatalyst but also paves an avenue to understand the heterostructure engineering for catalysts development and disclose the underlying relationship of interfacial electronic structures and catalytic properties.展开更多
Multifunctional catalysts that integrate high efficiency hydrogen evolution reaction(HER), oxygen evolution reaction(OER) and oxygen reduction reaction(ORR) catalytic activity in a single material are attractive for u...Multifunctional catalysts that integrate high efficiency hydrogen evolution reaction(HER), oxygen evolution reaction(OER) and oxygen reduction reaction(ORR) catalytic activity in a single material are attractive for unitized regenerative fuel cells and overall water splitting technologies. As the best-known HER and ORR electrocatalysts, Pt and its alloys have only moderate OER activity. Ruthenium and iridium oxides exhibit the highest OER activities but not as active as Pt for HER and ORR. Here, we proposed a general principle for achieving trifunctional electrocatalysis for three reactions in a single material. Using the newly-synthesized pyrazine-modified graphdiyne(PR-GDY) as an example, we demonstrated that the synergistic effect of the pyridinic nitrogen and anchored transition-metal(TM) single atoms renders highly-efficient HER/OER/ORR trifunctional electrocatalytic activity. For the Ni-doped PR-GDY, the overpotentials for HER, OER and ORR can be respectively as low as -0.05, 0.29 and 0.38 V, which are comparable or even superior to the best-known single-functional and bi-functional precious electrocatalysts.These computational results offer not only a promising trifunctional electrocatalyst but also a strategy for the design of multifunctional electrocatalysts.展开更多
The widespread use of multifunctional metasurfaces has started to revolutionize conventional electromagnetic devices due to their unprecedented capabilities and exceedingly low losses.Specifically,geometric metasurfac...The widespread use of multifunctional metasurfaces has started to revolutionize conventional electromagnetic devices due to their unprecedented capabilities and exceedingly low losses.Specifically,geometric metasurfaces that utilize spatially varied single-celled elements to impart arbitrary phase modulation under circularly polarized(CP)waves have attracted more attention.However,the geometric phase has intrinsically opposite signs for two spins,resulting in locked and mirrored functionalities for the right-handed and left-handed CP beams.Additionally,the demonstrated geometric metasurfaces so far have been limited to operating in either transmission or reflection modes at a single wavelength.Here,we propose a double-layered metasurface composed of complementary elliptical and reversal ring resonator structures to achieve simultaneous and independent control of the reflection and transmission of CP waves at two independent terahertz frequencies,which integrates three functions of reflected beam deflection,reflected Bessel beam generation,and transmitted beam focusing on the whole space.The high efficiency and simple design of our metasurface will open new avenues for integrated terahertz metadevices with advanced functionalities.展开更多
Acute fatty liver of pregnancy (AFLP) is a serious maternal illness occurring in the third trimester of pregnancy with significant perinatal and maternal mortality. Till recently, it has been considered a mysterious i...Acute fatty liver of pregnancy (AFLP) is a serious maternal illness occurring in the third trimester of pregnancy with significant perinatal and maternal mortality. Till recently, it has been considered a mysterious illness. In this editorial, we review the recent advances in understanding the pathogenesis of AFLP and discuss the studies documenting a fetal-maternal interaction with a causative association between carrying a fetus with a defect in mitochondrial fatty acid oxidation and development of AFLP. Further, we discuss the impact of these recent advances on the offspring born to women who develop AFLP, such that screening for a genetic defect can be life saving to the newborn and would allow genetic counseling in subsequent pregnancies. The molecular basis and underlying mechanism for this unique fetal-maternal interaction causing maternal liver disease is discussed.展开更多
Multifunctional non-precious catalysts for hydrogen/oxygen evolution reaction(HER/OER) and oxygen reduction reaction(ORR) constitute the bottleneck in the applications in electrochemical overall water splitting(OWS) a...Multifunctional non-precious catalysts for hydrogen/oxygen evolution reaction(HER/OER) and oxygen reduction reaction(ORR) constitute the bottleneck in the applications in electrochemical overall water splitting(OWS) and Zn-air batteries. Herein, a trifunctional electrocatalyst of urchin-like Al,P-codoped Co3O4 microspheres supported on Ni foam(denoted as AP-CONPs/NF) was fabricated via a hydrothermal process and subsequent low-temperature annealing and phosphorization, exhibiting enhanced OER, HER and ORR activities compared with single-doped and undoped samples. Their surface self-organized microstructure and excellent "superaerophobic" feature make a high bubble repellency, which boost diffusion of reactants and electrolyte-electrode intimate contact. The codoping of Al and P elements into Co3O4 betters right the balance among surface chemical state, the increased oxygen vacancies and the promoted charge transfer. Encouraged by these synergistic advantages, the AP-CONPs/NF was further employed as excellent bifunctional electrodes for the OWS(low cell voltage of 1.57 V at 10 mA cm-2) and as air cathode for rechargeable Zn-air batteries(high power density of 89.1 mW cm-2), which demonstrates a great feasibility for practical applications.展开更多
Due to the growing demand for clean and renewable hydrogen fuel,there has been a surge of interest in electrocatalytic water-splitting devices driven by renewable energy sources.However,the feasibility of self-driven ...Due to the growing demand for clean and renewable hydrogen fuel,there has been a surge of interest in electrocatalytic water-splitting devices driven by renewable energy sources.However,the feasibility of self-driven water splitting is limited by inefficient connections between functional modules,lack of highly active and stable electrocatalysts,and intermittent and unpredictable renewable energy supply.Herein,we construct a dualmodulated three-dimensional(3D)NiCo_(2)O_(4)@NiCo_(2)S_(4)(denoted as NCONCS)heterostructure deposited on nickel foam as a multifunctional electrode for electrocatalytic water splitting driven by photovoltaic-powered supercapacitors.Due to a stable 3D architecture configuration,abundant active sites,efficient charge transfer,and tuned interface properties,the NCONCS delivers a high specific capacity and rate performance for supercapacitors.A twoelectrode electrolyzer assembled with the NCONCS as both the anode and the cathode only requires a low cell voltage of 1.47 V to achieve a current density of 10 mA cm^(−2) in alkaline electrolyte,which outperforms the state-of-the-art bifunctional electrocatalysts.Theoretical calculations suggest that the generated heterointerfaces in NCONCS improve the surface binding capability of reaction intermediates while regulating the local electronic structures,which thus accelerates the reaction kinetics of water electrolysis.As a proof of concept,an integrated configuration comprising a two-electrode electrolyzer driven by two series-connected supercapacitors charged by a solar cell delivers a high product yield with superior durability.展开更多
Low discharge capacity and poor cycle stability are the major obstacles hindering the operation of Li-O_(2)batteries with highenergy-density.These obstacles are mainly caused by the cathode passivation behaviours and ...Low discharge capacity and poor cycle stability are the major obstacles hindering the operation of Li-O_(2)batteries with highenergy-density.These obstacles are mainly caused by the cathode passivation behaviours and the accumulation of by-products.Promoting the discharge process in solution and accelerating the decomposition of discharge products and by-products are able to alleviate above problems to some extent.Herein,chiral salen-Co(Ⅱ)complex,(1R,2R)-(-)-N,N-bis(3,5-di-t-butylsalicylidene)-1,2-cyclohexanediaminocobalt(Ⅱ)(Co(Ⅱ))as a multi-functional redox mediator was introduced into electrolyte to induce solution phase formation of Li_(2)O_(2)and catalyze the oxidation of Li_(2)O_(2)and main by-products Li_(2)CO3.Due to the Co(Ⅱ)has the solvation effect towards Li+,it can drive solution phase formation of Li_(2)O_(2),to prevent electrode from passivation and then increase the discharge capacity with a high Li_(2)O_(2)yield of 96.09%.Furthermore,the Co(Ⅱ)possesses suitable redox couple potentials,and it does so while simultaneously boosting the oxidization of Li_(2)O_(2)and the decomposition of Li_(2)CO3,reducing charge overpotential,and promoting cycle lifespan.Thereby,a cell with Co(Ⅱ)achieved a long cycling stability at low charge plateau(3.66 V)over 252 cycles with a specific capacity of 500 mAh·gcarbon^(−1).展开更多
基金National Research Foundation of Korea,Grant/Award Numbers:NRF-2020R1A3B2079803,2021R1A2C2007804。
文摘Herein,we have designed a highly active and robust trifunctional electrocatalyst derived from Prussian blue analogs,where Co_(4)N nanoparticles are encapsulated by Fe embedded in N-doped carbon nanocubes to synthesize hierarchically structured Co_(4)N@Fe/N-C for rechargeable zinc-air batteries and overall water-splitting electrolyzers.As confirmed by theoretical and experimental results,the high intrinsic oxygen reduction reaction,oxygen evolution reaction,and hydrogen evolution reaction activities of Co_(4)N@Fe/N-C were attributed to the formation of the heterointerface and the modulated local electronic structure.Moreover,Co_(4)N@Fe/N-C induced improvement in these trifunctional electrocatalytic activities owing to the hierarchical hollow nanocube structure,uniform distribution of Co_(4)N,and conductive encapsulation by Fe/N-C.Thus,the rechargeable zinc-air battery with Co_(4)N@Fe/N-C delivers a high specific capacity of 789.9 mAh g^(-1) and stable voltage profiles over 500 cycles.Furthermore,the overall water electrolyzer with Co_(4)N@Fe/N-C achieved better durability and rate performance than that with the Pt/C and IrO2 catalysts,delivering a high Faradaic efficiency of 96.4%.Along with the great potential of the integrated water electrolyzer powered by a zinc-air battery for practical applications,therefore,the mechanistic understanding and active site identification provide valuable insights into the rational design of advanced multifunctional electrocatalysts for energy storage and conversion.
基金funded by grants from the Natural Science Foundation of China(21771101)supported by Jiangsu Cyan Engineering of Higher Education+2 种基金Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Jiangsu Joint Laboratory of Atmospheric Pollution ControlJiangsu Engineering Technology Research Center of Environmental Cleaning Materials。
文摘Development of high-efficiency non-noble electrocatalysts for oxygen reduction reaction(ORR),oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is urgently needed for high-performance Zn-air batteries and overall water splitting.Here,a facile strategy to synthesize novel Co-MOF,O-doped carbon(Co-MOF-T)based on Zn,Co-doped glucosamine and ZIF-8 by pyrolysis at temperature T was demonstrated.The prepared Co-MOF-800 showed a superior oxygen reduction reaction(ORR)activity comparable to that of commercial Pt/C catalyst.In addition,this catalyst shows great potential in the overall water splitting due to the excellent oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)activities.Based on the trifunctional activity,the primary Zn-air batteries using a Co-MOF-800 air electrode achieved a high open-circuit voltage of 1.38 V,a specific capacity of 671.6 mAh g^(-1) Zn,and a prominent peak power density of 144 mW cm^(-2).Also,the rechargeable Zn-air batteries based on CoMOF-800 air electrode could be smoothly run for 510 cycles with a low voltage gap of 0.58 V.Finally,the trifunctional Co-MOF-800 catalyst was applied to boost the electrochemical water splitting,demonstrating its promising potential as a green energy material for practical applications.
基金financially supported by the National Natural Science Foundation of China (Grants Nos. 51972349, U1801255 and 91963210)。
文摘To meet the practical demand of wearable/portable electronics, developing high-efficiency and durable multifunctional catalyst and in-situ assembling catalysts into electrodes with flexible features are urgently needed but challenging. Herein, we report a simple route to fabricate bendable multifunctional electrodes by in-situ carbonization of metal ion absorbed polyaniline precursor. Alloy nanoparticles encapsulated in graphite layer are uniformly distributed in the N-doping carbon nanorod skeleton. Profiting from the favorable free-standing structure and the cooperative effect of metallic nanoparticles, graphitic layer and N doped-carbon architecture, the trifunctional electrodes exhibit prominent activities and stability toward HER, OER and ORR. Notably, due to the protection of carbon layer, the electrocatalysts show the reversible catalytic HER/OER properties. The overall water splitting device can continuously work for 12 h under frequent exchanges of cathode and anode. Importantly, the bendable metal air batteries fabricated by self-supported electrode not only displays the outstanding battery performance,achieving a decent peak power density(125 mW cm^(-2)) and exhibiting favorable charge-discharge durability of 22 h, but also holds superb flexible stability. Specially, a lightweight self-driven water splitting unit is demonstrated with stable hydrogen production.
基金supported by the Hunan Provincial Natural Science Foundation (2021JJ30087)the Science and Technology Innovation Program of Hunan Province (2022WZ1012)the Fundamental Research Funds for the Central Universities and Guangxi Key Laboratory of Information Materials&Guilin University of Electronic Technology,China (211011K)。
文摘The development of single electrode with multifunctional purposes for electrochemical devices remains a symbolic challenge in recent technology.This work explores interfacially-rich transition metal nitride hybrid that consist of nickel nitride and vanadium oxynitride(VO_(0.26)N_(0.52))on robust carbon fiber(denoted CF/Ni_(3)N/VON)as trifunctional electrode for hydrogen evolution reaction(HER),oxygen evolution reaction(OER),and sodium ion batteries(SIBs).The as-prepared CF/Ni_(3)N/VON exhibits low HER overpotential of 48 m V@10 m A cm^(-2),OER overpotential of 287 m V@10 m A cm^(-2),and sodium-ion anode storage reversible capacity of 555 m A h g^(-1)@0.2 C.Theoretical analyses reveal that the Ni_(3)N effectively facilitates hydrogen desorption for HER,increases the electrical conductivity for OER,and promotes the Na-ion storage intercalation process,while the VON substantially elevates the water dissociation kinetics for HER,accelerates the adsorption of OH*intermediate for OER and enhances the Na-ion surface adsorption storage process.Owing to the excellent HER and OER performances of the CF/Ni_(3)N/VON electrode,an overall water splitting device denoted as CF/Ni_(3)N/VON//CF/Ni_(3)N/VON was not only assembled showing an operating voltage of 1.63 V at current density of 10 m A cm^(-2)but was also successfully self-powered by the assembled CF/Ni_(3)N/VON//CF/Na_(3)V_(2)(PO_(4))_(3) flexible sodium ion battery.This work will contribute to the development of efficient and cost-effective flexible integrated electrochemical energy devices.
文摘Hydrolytic polymerization of 8 - caprolactam is carried out by the use of trimesinic acid as molecular weight controlling agent, and polyamide 6 with three branched chains is obtained. The initial concentrations of regulators almost have no effect on the conversion of caprolactam , while relative viscosity of the polymer is affected by the concentrations. DSC investigation shows that DSC curve changes from single peak for regular polyamide 6 to one peak with one shoulder or one small peak for polyamide 6 with three branched chains and the melting point decreases with the increase of the amount of trimesinic acid. In addition, the concentration of trimesinic acid being the same, DSC curves change from almost sharp single peak to double peak with increasing reaction time.
基金financially supported by the National Natural Science Foundation of China (22075211, 62005173 and 21601136)Tianjin Science Fund for Distinguished Young Scholars (19JCJQJC61800)+1 种基金the Research Fund of State Key Laboratory for Marine Corrosion and Protection of Luoyang Ship Material Research Institute (LSMRI) under the contract No. KF190411the Science and Technology Development Fund of Tianjin Education Commission for Higher Education (2018KJ126)。
文摘The development of robust and efficient trifunctional catalysts showing excellent oxygen evolution reaction(OER), oxygen reduction reaction(ORR) and hydrogen evolution reaction(HER) kinetics has been challenging.Herein, we prepared a hybrid iron and cobalt-based metal alloy phosphide on a phosphorus and nitrogen co-doped carbon substrate(Fe Co-P/PNC) as a catalyst using a one-step Pregulation method. The catalyst exhibited a positive half-wave potential of 0.86 V versus the reversible hydrogen electrode(RHE) for ORR, and low overpotentials of 350 and 158 m V for OER and HER, respectively, to achieve a current density of10 m A cm^(-2). Density functional theory calculations demonstrated the dominant role of P in both Fe Co phosphide and carbon matrix, which led to the good ORR, OER and HER kinetics. The assembled aqueous and flexible Zn-air batteries with Fe Co-P/PNC as the air cathode displayed excellent peak power densities of 195.1 and 90.8 m W cm^(-2), respectively, as well as outstanding charging-discharging performance, long lifetime, and high flexibility. Moreover, the self-powered overall water-splitting cell exhibited a low working voltage of1.71 V to achieve a current density of 10 m A cm^(-2), confirming its excellent multifunctional OER/ORR/HER activity.
基金the National Natural Science Foundation of China(Nos.22179014 and 21603019)the Fundamental Research Funds for the Central Universities(No.2021CDJQY-051)+1 种基金the Key Program for International Science and Technology Cooperation Projects of Ministry of Science and Technology of China(No.2016YFE0125900)the Hundred Talents Program of Chongqing University。
文摘Rational design of highly efficient,robust and nonprecious electrocatalysts for the oxygen reduction reaction(ORR),oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is highly demanded and challenging.Here,heterostructural Co_(3O)_(4)@Ni_(2)P arrays with numerous reaction sites,unique interfacial electronic structure and fast charge transfer kinetics are developed as electrocatalysts for rechargeable Zn-air batteries and overall water splitting.Both density functional theory calculation and X-ray absorption fine structure analysis manifest that the synergistic structural and abundant electronic modulations interfaces are formed,thus simultaneously promoting the electrocatalytic kinetics,activities and stabilities.Specifically,it can achieve an ultralow overpotential of 270 m V and 28 m V at 10 m A cm^(-2) for OER and HER,respectively.The water electrolyzer delivers a current density of 10 m A cm^(-2) at 1.563 V;furthermore,rechargeable Zn-air batteries triggered by this heterostructure can achieve excellent cyclic stability of 177 h(2 h per cycle)at 10 m A cm^(-2);both devices are superior to the Pt/C+Ir/C.This work not only designs an efficient trifunctional electrocatalyst but also paves an avenue to understand the heterostructure engineering for catalysts development and disclose the underlying relationship of interfacial electronic structures and catalytic properties.
基金supported by the Basic Research Project of Natural Science Foundation of Shandong Province(ZR2018ZB0751)the National Natural Science Foundation of China(11774201)the Taishan Scholar Program of Shandong Province。
文摘Multifunctional catalysts that integrate high efficiency hydrogen evolution reaction(HER), oxygen evolution reaction(OER) and oxygen reduction reaction(ORR) catalytic activity in a single material are attractive for unitized regenerative fuel cells and overall water splitting technologies. As the best-known HER and ORR electrocatalysts, Pt and its alloys have only moderate OER activity. Ruthenium and iridium oxides exhibit the highest OER activities but not as active as Pt for HER and ORR. Here, we proposed a general principle for achieving trifunctional electrocatalysis for three reactions in a single material. Using the newly-synthesized pyrazine-modified graphdiyne(PR-GDY) as an example, we demonstrated that the synergistic effect of the pyridinic nitrogen and anchored transition-metal(TM) single atoms renders highly-efficient HER/OER/ORR trifunctional electrocatalytic activity. For the Ni-doped PR-GDY, the overpotentials for HER, OER and ORR can be respectively as low as -0.05, 0.29 and 0.38 V, which are comparable or even superior to the best-known single-functional and bi-functional precious electrocatalysts.These computational results offer not only a promising trifunctional electrocatalyst but also a strategy for the design of multifunctional electrocatalysts.
基金supported by the Villum Fonden(No.37372)Independent Research Fund Denmark(No.1134-00010B)+1 种基金NaturalScienceFoundationofZhejiangProvince(No.LY19A040004)Natural Science Foundation of Ningbo(No.2021J073)。
文摘The widespread use of multifunctional metasurfaces has started to revolutionize conventional electromagnetic devices due to their unprecedented capabilities and exceedingly low losses.Specifically,geometric metasurfaces that utilize spatially varied single-celled elements to impart arbitrary phase modulation under circularly polarized(CP)waves have attracted more attention.However,the geometric phase has intrinsically opposite signs for two spins,resulting in locked and mirrored functionalities for the right-handed and left-handed CP beams.Additionally,the demonstrated geometric metasurfaces so far have been limited to operating in either transmission or reflection modes at a single wavelength.Here,we propose a double-layered metasurface composed of complementary elliptical and reversal ring resonator structures to achieve simultaneous and independent control of the reflection and transmission of CP waves at two independent terahertz frequencies,which integrates three functions of reflected beam deflection,reflected Bessel beam generation,and transmitted beam focusing on the whole space.The high efficiency and simple design of our metasurface will open new avenues for integrated terahertz metadevices with advanced functionalities.
文摘Acute fatty liver of pregnancy (AFLP) is a serious maternal illness occurring in the third trimester of pregnancy with significant perinatal and maternal mortality. Till recently, it has been considered a mysterious illness. In this editorial, we review the recent advances in understanding the pathogenesis of AFLP and discuss the studies documenting a fetal-maternal interaction with a causative association between carrying a fetus with a defect in mitochondrial fatty acid oxidation and development of AFLP. Further, we discuss the impact of these recent advances on the offspring born to women who develop AFLP, such that screening for a genetic defect can be life saving to the newborn and would allow genetic counseling in subsequent pregnancies. The molecular basis and underlying mechanism for this unique fetal-maternal interaction causing maternal liver disease is discussed.
基金the National Natural Science Foundation of China(21421001,21573115,21875118)the Natural Science Foundation of Tianjin(17JCYBJC17100,19JCZDJC37700)。
文摘Multifunctional non-precious catalysts for hydrogen/oxygen evolution reaction(HER/OER) and oxygen reduction reaction(ORR) constitute the bottleneck in the applications in electrochemical overall water splitting(OWS) and Zn-air batteries. Herein, a trifunctional electrocatalyst of urchin-like Al,P-codoped Co3O4 microspheres supported on Ni foam(denoted as AP-CONPs/NF) was fabricated via a hydrothermal process and subsequent low-temperature annealing and phosphorization, exhibiting enhanced OER, HER and ORR activities compared with single-doped and undoped samples. Their surface self-organized microstructure and excellent "superaerophobic" feature make a high bubble repellency, which boost diffusion of reactants and electrolyte-electrode intimate contact. The codoping of Al and P elements into Co3O4 betters right the balance among surface chemical state, the increased oxygen vacancies and the promoted charge transfer. Encouraged by these synergistic advantages, the AP-CONPs/NF was further employed as excellent bifunctional electrodes for the OWS(low cell voltage of 1.57 V at 10 mA cm-2) and as air cathode for rechargeable Zn-air batteries(high power density of 89.1 mW cm-2), which demonstrates a great feasibility for practical applications.
文摘Due to the growing demand for clean and renewable hydrogen fuel,there has been a surge of interest in electrocatalytic water-splitting devices driven by renewable energy sources.However,the feasibility of self-driven water splitting is limited by inefficient connections between functional modules,lack of highly active and stable electrocatalysts,and intermittent and unpredictable renewable energy supply.Herein,we construct a dualmodulated three-dimensional(3D)NiCo_(2)O_(4)@NiCo_(2)S_(4)(denoted as NCONCS)heterostructure deposited on nickel foam as a multifunctional electrode for electrocatalytic water splitting driven by photovoltaic-powered supercapacitors.Due to a stable 3D architecture configuration,abundant active sites,efficient charge transfer,and tuned interface properties,the NCONCS delivers a high specific capacity and rate performance for supercapacitors.A twoelectrode electrolyzer assembled with the NCONCS as both the anode and the cathode only requires a low cell voltage of 1.47 V to achieve a current density of 10 mA cm^(−2) in alkaline electrolyte,which outperforms the state-of-the-art bifunctional electrocatalysts.Theoretical calculations suggest that the generated heterointerfaces in NCONCS improve the surface binding capability of reaction intermediates while regulating the local electronic structures,which thus accelerates the reaction kinetics of water electrolysis.As a proof of concept,an integrated configuration comprising a two-electrode electrolyzer driven by two series-connected supercapacitors charged by a solar cell delivers a high product yield with superior durability.
基金the National Key Research and Development Program of China(No.2017YFA0206703)the National Natural Science Foundation of China(No.22075270)+2 种基金the National Natural Science Foundation of China(No.21903019)the Top Young Talents Program in University of Hebei Province(No.BJ2020014)the numerical calculations in this paper have been done on the supercomputing system in the Supercomputing Center of University of Science and Technology of China.
文摘Low discharge capacity and poor cycle stability are the major obstacles hindering the operation of Li-O_(2)batteries with highenergy-density.These obstacles are mainly caused by the cathode passivation behaviours and the accumulation of by-products.Promoting the discharge process in solution and accelerating the decomposition of discharge products and by-products are able to alleviate above problems to some extent.Herein,chiral salen-Co(Ⅱ)complex,(1R,2R)-(-)-N,N-bis(3,5-di-t-butylsalicylidene)-1,2-cyclohexanediaminocobalt(Ⅱ)(Co(Ⅱ))as a multi-functional redox mediator was introduced into electrolyte to induce solution phase formation of Li_(2)O_(2)and catalyze the oxidation of Li_(2)O_(2)and main by-products Li_(2)CO3.Due to the Co(Ⅱ)has the solvation effect towards Li+,it can drive solution phase formation of Li_(2)O_(2),to prevent electrode from passivation and then increase the discharge capacity with a high Li_(2)O_(2)yield of 96.09%.Furthermore,the Co(Ⅱ)possesses suitable redox couple potentials,and it does so while simultaneously boosting the oxidization of Li_(2)O_(2)and the decomposition of Li_(2)CO3,reducing charge overpotential,and promoting cycle lifespan.Thereby,a cell with Co(Ⅱ)achieved a long cycling stability at low charge plateau(3.66 V)over 252 cycles with a specific capacity of 500 mAh·gcarbon^(−1).
