As anode materials for high-performance sodium-ion batteries and potassium-ion batteries,bimetallic selenides have attracted great concern due to their relatively high electrical conductivity and electrochemical activ...As anode materials for high-performance sodium-ion batteries and potassium-ion batteries,bimetallic selenides have attracted great concern due to their relatively high electrical conductivity and electrochemical activity.However,the formidable challenge in the reaction process is the large volume change,leading to the structural collapse of material,and eventually the decline in electrochemical performance.Herein,a composite of hierarchical CoSe_(2)–MoSe_(2) tubes anchored on reduced graphene oxide nanosheets(CoSe_(2)–MoSe_(2)/rGO)is designed by an in situ hydrothermal selenization treatment.Benefiting from the synergistic effects between CoSe_(2) and MoSe_(2),unique hierarchical structure,and effective reduced graphene oxide coating,the CoSe_(2)–MoSe_(2)/rGO exhibited improved reaction kinetics and structural stability,and thus good electrochemical properties.A combination mechanism of intercalation and conversion of CoSe_(2)–MoSe_(2)/rGO by forming NaxCoSe_(2) and Mo_(15)Se_(19) as intermediate states is put forward on the basis of in situ and ex situ XRD analyses.展开更多
Electrolytic water splitting,as a promising route to hydrogen(H_(2))production,is still confronted with the sluggish anodic oxygen evolution reaction(OER)and its less value-added O2 production.Herein,we report a bifun...Electrolytic water splitting,as a promising route to hydrogen(H_(2))production,is still confronted with the sluggish anodic oxygen evolution reaction(OER)and its less value-added O2 production.Herein,we report a bifunctional electrode fabricated by in situ growth of Mn-doped CoSe_(2)nanonetworks on carbon fiber cloth(Mn-CoSe_(2)/CFC),which shows attractive electrocatalytic properties toward glycerol oxidation reaction(GOR)in alkali and hydrogen evolution reaction(HER)in acid.A flow alkali/acid hybrid electrolytic cell(fA/A-hEC)was then developed by coupling anodic GOR with cathodic HER with the Mn-CoSe_(2)/CFC bifunctional electrode.Such fA/A-hEC enables a rather low voltage of 0.54 V to achieve 10 mA cm^(-2),and maintain long-term electrolysis stability over 300-h operation at 100 mA cm^(-2)with Faraday efficiencies of over 99%for H_(2)and 90%for formate production.The designed bifunctional electrode in such innovative fA/A-hEC device provides insightful guidance for coupling energy-efficient hydrogen production with biomass upgradation.展开更多
Electrocatalytic oxygen reduction(ORR)via the 2e−pathway to form H_(2)O_(2) in acidic medium has attracted extensive attention.However,the low activity,insufficient selectivity and high cost of catalysts have been the...Electrocatalytic oxygen reduction(ORR)via the 2e−pathway to form H_(2)O_(2) in acidic medium has attracted extensive attention.However,the low activity,insufficient selectivity and high cost of catalysts have been the bottlenecks.Herein,CoSe_(2) with abundant Se deficiency was synthesized by a simple hydrothermal method,and the addition of NaBH4-induced CoSe_(2) phase transition from orthorhombic to cubic phase with more Se deficiency.The cubic phase CoSe_(2) with abundant Se deficiency can effectively regulate the surface electronic structure with suitable binding energies of*OOH and*O,which shows high activity,selectivity and long-term stability for acidic ORR to H_(2)O_(2).The onset potential is as low as 0.73 V vs.reversible hydrogen electrode(RHE),the H_(2)O_(2) selectivity is 84%(0 V vs.RHE),and the average electron transfer number is about 2.3.Furthermore,the H_(2)O_(2) yield measured using a flow cell is as high as 115.92 mmol·gcat.^(−1)·h^(−1) and the Faradaic efficiency is 70%at 0 V vs.RHE,which presents high potential in electrocatalytic acidic ORR to H_(2)O_(2) and organic pollutant degradation using the electron-Fenton process.展开更多
Constructing heterostructure is considered as an effective strategy to address the sluggish electronic and ionic kinetics of anode materials for sodium ion batteries(SIBs).However,realizing the orientated growth and u...Constructing heterostructure is considered as an effective strategy to address the sluggish electronic and ionic kinetics of anode materials for sodium ion batteries(SIBs).However,realizing the orientated growth and uniform distribution of the heterostructure is still a great challenge.Herein,the regulated novel CoSe_(2)/NiSe_(2)heterostructure confined in N-doped carbon nanofibers(CoSe_(2)/NiSe_(2)@N-C)are prepared by using Co/Ni-ZIF template,in which,the CoSe_(2)/NiSe_(2)heterostructures realize uniform distribution on a micro level.Benefiting from the unique heterostructure and N-doped carbon nanofibers,the CoSe_(2)/NiSe_(2)@N-C deliveries superior rate capability and durable cycle lifespan with a reversible capacity of 400.5 mA h g^(-1)after 5000 cycles at 2 A g^(-1).The Na-ion full battery with CoSe_(2)/NiSe_(2)@N-C anode and layered oxide cathode displays a remarkable energy density of 563 W h kg^(-1)with 241.1 W kg^(-1)at 0.1 A g^(-1).The theoretical calculations disclose that the periodic and directional built-in electric-field along with the heterointerfaces of CoSe_(2)/NiSe_(2)@N-C can accelerate electrochemical reaction kinetics.The in(ex)situ experimental measurements reveal the reversible conversion reaction and stable structure of CoSe_(2)/NiSe_(2)@N-C during Na+insertion/extraction.The study highlights the potential ability of precisely controlled heterostructure to stimulate the electrochemical performances of advanced anode for SIBs.展开更多
具有高理论容量和高能量密度的锂硫电池被认为是最具前景的储能器件,但其实用化进程受到了多硫化物穿梭效应和氧化还原动力学缓慢等问题的影响.本文将CoSe_(2)纳米颗粒修饰的碳纳米纤维/碳纳米管(CoSe_(2)@CNF/CNT)自支撑膜作为高性能...具有高理论容量和高能量密度的锂硫电池被认为是最具前景的储能器件,但其实用化进程受到了多硫化物穿梭效应和氧化还原动力学缓慢等问题的影响.本文将CoSe_(2)纳米颗粒修饰的碳纳米纤维/碳纳米管(CoSe_(2)@CNF/CNT)自支撑膜作为高性能锂硫电池硫宿主电极.其中,由氮掺杂多孔碳和CNF/CNT组成的导电碳网络能够促进电荷传输,并缓解硫在循环过程中的体积膨胀.CoSe_(2)纳米颗粒兼具化学吸附位点和电催化剂的功能,通过化学吸附锚定多硫化物并加速其氧化还原转换,从而抑制穿梭效应和提高性能.因此CoSe_(2)@CNF/CNT-S电极具有优异的电化学性能,1 C下能提供1098.8 mA h g^(−1)的放电比容量,循环500圈中每圈容量衰减率低至0.06%.这项工作为高能量密度锂硫电池的开发提供了一种新方案.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.21701144)。
文摘As anode materials for high-performance sodium-ion batteries and potassium-ion batteries,bimetallic selenides have attracted great concern due to their relatively high electrical conductivity and electrochemical activity.However,the formidable challenge in the reaction process is the large volume change,leading to the structural collapse of material,and eventually the decline in electrochemical performance.Herein,a composite of hierarchical CoSe_(2)–MoSe_(2) tubes anchored on reduced graphene oxide nanosheets(CoSe_(2)–MoSe_(2)/rGO)is designed by an in situ hydrothermal selenization treatment.Benefiting from the synergistic effects between CoSe_(2) and MoSe_(2),unique hierarchical structure,and effective reduced graphene oxide coating,the CoSe_(2)–MoSe_(2)/rGO exhibited improved reaction kinetics and structural stability,and thus good electrochemical properties.A combination mechanism of intercalation and conversion of CoSe_(2)–MoSe_(2)/rGO by forming NaxCoSe_(2) and Mo_(15)Se_(19) as intermediate states is put forward on the basis of in situ and ex situ XRD analyses.
基金supported by the National Natural Science Foundation of China(Project No.21875253)the CAS Commonwealth Scientific and Industrial Research Organization(CSIRO)Joint Research Projects(121835KYSB20200039)+3 种基金the Scientific Research and Equipment Development Project of CAS(YJKYYQ20190007)Fujian Natural Science Foundation(2021J01210293)the Fujian Science and Technology Pilot Project(Project No.2020H0039)the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(Grant.YLUDNL Fund 2021011)。
文摘Electrolytic water splitting,as a promising route to hydrogen(H_(2))production,is still confronted with the sluggish anodic oxygen evolution reaction(OER)and its less value-added O2 production.Herein,we report a bifunctional electrode fabricated by in situ growth of Mn-doped CoSe_(2)nanonetworks on carbon fiber cloth(Mn-CoSe_(2)/CFC),which shows attractive electrocatalytic properties toward glycerol oxidation reaction(GOR)in alkali and hydrogen evolution reaction(HER)in acid.A flow alkali/acid hybrid electrolytic cell(fA/A-hEC)was then developed by coupling anodic GOR with cathodic HER with the Mn-CoSe_(2)/CFC bifunctional electrode.Such fA/A-hEC enables a rather low voltage of 0.54 V to achieve 10 mA cm^(-2),and maintain long-term electrolysis stability over 300-h operation at 100 mA cm^(-2)with Faraday efficiencies of over 99%for H_(2)and 90%for formate production.The designed bifunctional electrode in such innovative fA/A-hEC device provides insightful guidance for coupling energy-efficient hydrogen production with biomass upgradation.
基金This study was financially supported by the Natural Science Foundation of Shandong(Nos.ZR2022QB236 and ZR2020KB011)the National Natural Science Foundation of China(Nos.21878063 and 22005168)+1 种基金Taishan Scholars Program(No.tsqn201909119)China Postdoctoral Science Foundation(No.2022M722363).
文摘Electrocatalytic oxygen reduction(ORR)via the 2e−pathway to form H_(2)O_(2) in acidic medium has attracted extensive attention.However,the low activity,insufficient selectivity and high cost of catalysts have been the bottlenecks.Herein,CoSe_(2) with abundant Se deficiency was synthesized by a simple hydrothermal method,and the addition of NaBH4-induced CoSe_(2) phase transition from orthorhombic to cubic phase with more Se deficiency.The cubic phase CoSe_(2) with abundant Se deficiency can effectively regulate the surface electronic structure with suitable binding energies of*OOH and*O,which shows high activity,selectivity and long-term stability for acidic ORR to H_(2)O_(2).The onset potential is as low as 0.73 V vs.reversible hydrogen electrode(RHE),the H_(2)O_(2) selectivity is 84%(0 V vs.RHE),and the average electron transfer number is about 2.3.Furthermore,the H_(2)O_(2) yield measured using a flow cell is as high as 115.92 mmol·gcat.^(−1)·h^(−1) and the Faradaic efficiency is 70%at 0 V vs.RHE,which presents high potential in electrocatalytic acidic ORR to H_(2)O_(2) and organic pollutant degradation using the electron-Fenton process.
基金financially supported by the Natural Science Foundation of Shandong Province(ZR2021QB055,ZR2023MB017,ZR2022JQ10)the National Natural Science Foundation of China(21901146,220781792,22274083)。
文摘Constructing heterostructure is considered as an effective strategy to address the sluggish electronic and ionic kinetics of anode materials for sodium ion batteries(SIBs).However,realizing the orientated growth and uniform distribution of the heterostructure is still a great challenge.Herein,the regulated novel CoSe_(2)/NiSe_(2)heterostructure confined in N-doped carbon nanofibers(CoSe_(2)/NiSe_(2)@N-C)are prepared by using Co/Ni-ZIF template,in which,the CoSe_(2)/NiSe_(2)heterostructures realize uniform distribution on a micro level.Benefiting from the unique heterostructure and N-doped carbon nanofibers,the CoSe_(2)/NiSe_(2)@N-C deliveries superior rate capability and durable cycle lifespan with a reversible capacity of 400.5 mA h g^(-1)after 5000 cycles at 2 A g^(-1).The Na-ion full battery with CoSe_(2)/NiSe_(2)@N-C anode and layered oxide cathode displays a remarkable energy density of 563 W h kg^(-1)with 241.1 W kg^(-1)at 0.1 A g^(-1).The theoretical calculations disclose that the periodic and directional built-in electric-field along with the heterointerfaces of CoSe_(2)/NiSe_(2)@N-C can accelerate electrochemical reaction kinetics.The in(ex)situ experimental measurements reveal the reversible conversion reaction and stable structure of CoSe_(2)/NiSe_(2)@N-C during Na+insertion/extraction.The study highlights the potential ability of precisely controlled heterostructure to stimulate the electrochemical performances of advanced anode for SIBs.
基金supported by the National Natural Science Foundation of China(U22A20118)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZR146 and 2021ZZ122)the Award Program for Fujian Minjiang Scholar Professorship.
文摘具有高理论容量和高能量密度的锂硫电池被认为是最具前景的储能器件,但其实用化进程受到了多硫化物穿梭效应和氧化还原动力学缓慢等问题的影响.本文将CoSe_(2)纳米颗粒修饰的碳纳米纤维/碳纳米管(CoSe_(2)@CNF/CNT)自支撑膜作为高性能锂硫电池硫宿主电极.其中,由氮掺杂多孔碳和CNF/CNT组成的导电碳网络能够促进电荷传输,并缓解硫在循环过程中的体积膨胀.CoSe_(2)纳米颗粒兼具化学吸附位点和电催化剂的功能,通过化学吸附锚定多硫化物并加速其氧化还原转换,从而抑制穿梭效应和提高性能.因此CoSe_(2)@CNF/CNT-S电极具有优异的电化学性能,1 C下能提供1098.8 mA h g^(−1)的放电比容量,循环500圈中每圈容量衰减率低至0.06%.这项工作为高能量密度锂硫电池的开发提供了一种新方案.
