Hydrogen evolution reaction(HER) is a prospective method to generate pure hydrogen. The development of superior electrocatalysts based on earth-abundant materials, plays a critical role in the future.CoSe_2, one of th...Hydrogen evolution reaction(HER) is a prospective method to generate pure hydrogen. The development of superior electrocatalysts based on earth-abundant materials, plays a critical role in the future.CoSe_2, one of the earth-abundant electrocatalysts, has been proved to be a promising catalyst for hydrogen generation. In our work, flower-like CoSe_2 nanorods with high quality are successfully synthesized through a facile ethylenediaminetetraacetic acid ligand(EDTA)-assisted hydrothermal process. The flower-like CoSe_2 nanorods show the brilliant electrochemical HER performance with 100 mA cm^(-2) at overpotential of 273 m V, a small Tafel slope of 35 mV dec^(-1) and strong durability in acid solution. The sparkly HER catalytic activity of CoSe_2 can be ascribed to its particular structure with large surface area and abundant active sites. Therefore, this work offers an outstanding candidate for improving hydrogen production capabilities by water electrolysis.展开更多
Sodium-ion batteries are receiving more and more attention due to their low cost and abundant sodium storage capacity,and are considered to be a promising alternative to lithium-ion batteries.A large number of studies...Sodium-ion batteries are receiving more and more attention due to their low cost and abundant sodium storage capacity,and are considered to be a promising alternative to lithium-ion batteries.A large number of studies have shown that constructing heterostructures are considered an effective strategy to solve the hysteresis problem of electronic and ion dynamics in sodiumion battery anode materials.Herein,a nickel-cobalt bimetallic coordination polymer(NiCoCP)was synthesized using a coprecipitation method,and a CoSe_(2)@NiSe_(2) cross-stacked structure was obtained through high-temperature carbonization and selenization processes.CoSe_(2)@NiSe_(2) has a unique heterostructure and carbon film,which synergistically increases a large number of adsorption sites and alleviates the diffusion energy barrier,thereby improving the rapid diffusion kinetics of Na^(+)ions.It has superior rate performance and long-lasting cycle life.For sodium-ion batteries(SIBs),the specific capacity of CoSe_(2)@NiSe_(2) is around 460 mA h g^(-1) after 400 cycles at 1.0 A g^(-1).For potassium-ion batteries(PIBs),CoSe_(2)@NiSe_(2) also exhibits excellent cycling stability,maintaining a specific capacity of 160 mA h g^(-1) after 700 cycles at 1.0 A g^(-1).This study provides a new way to prepare metal selenide heterostructure as the promising anode material for SIBs.展开更多
The highly reversible insertion/extraction of large-radius K^+into electrode materials remains a tough goal,especially for con version-type materials.Herein,we design a current collector-integrated electrode(N-CoSe/Co...The highly reversible insertion/extraction of large-radius K^+into electrode materials remains a tough goal,especially for con version-type materials.Herein,we design a current collector-integrated electrode(N-CoSe/CoSe_(2)-C@Cu) as an advanced anode for potassium-ion battery(PIBs).The conductive CoSe/CoSe_(2) heterojunction with rich Se vacancy defects,conductive sp^2 N-doped carbon layer,and the elastic copper foil matrix can greatly accelerate the electron transfer and enhance the structural stability.Consequently,the well-designed N-CoSe/CoSe_(2)-C@Cu current collector-integrated electrode displays enhanced potassium storage performance with regard to a high capacity(325.1 mAh·g^(-1) at 0.1 A·g^(-1) after 200cycles),an exceptional rate capability(223.5 mAh·g^(-1) at2000 mA·g^(-1)),and an extraordinary long-term cycle stability(a capacity fading of only 0.019% per cycle over1200 cycles at 2000 mA·g^(-1)).Impressively,ex situ scanning electron microscopy(SEM) characterizations prove that the elastic structure of copper foil is merged into the cleverly designed N-CoSe/CoSe_(2)-C@Cu heterostructure,which buffers the deformation of structure and volume and greatly promotes the cycle life during the potassium/depotassium process.展开更多
Li-S battery has attracted great attention due to its high specific capacity and energy density.However,the serious polysulfides shuttle effect,low conductivity of sulfur and discharge product of lithium sulfide limit...Li-S battery has attracted great attention due to its high specific capacity and energy density.However,the serious polysulfides shuttle effect,low conductivity of sulfur and discharge product of lithium sulfide limit their application in commercial energy storage system.To solve the above problems,this work designs and constructs C@CoSe_(2) nano wire material as sulfur host for realizing high-performance Li-S battery.By combing the high conductivity,strong chemisorption,promising catalytic capacity and unique nanowire array structure,the C@CoSe_(2)/S electrode demonstrates a high specific capacity of 1264 mAh·g^(-1) with a low capacity decay of 0.051%per cycle at 0.2 C over 200 cycles.As expected,the battery delivers outstanding capacity retention over 1000 cycles at5 C and the decay is as low as≈0.026% per cycle.Moreover,even at higher sulfur loading of 5.1 mg·cm^(-2),the battery could still remain a stable areal capacity of 5.02 mAh·cm^(-2) at 0.2 C. More importantly,the experimental data and theoretical calculation results reveal that the internal mechanism of the improved electrochemical performance is the catalytic activation of CoSe_(2) on poly sulfides.展开更多
Hetero-structure induced high performance catalyst for oxygen evolution reaction(OER)in the water splitting reaction has received increased attention.Herein,we demonstrated a novel catalyst system of NiSe_(2)-CoSe_(2)...Hetero-structure induced high performance catalyst for oxygen evolution reaction(OER)in the water splitting reaction has received increased attention.Herein,we demonstrated a novel catalyst system of NiSe_(2)-CoSe_(2)consisting of nanorods and nanoparticles for the efficient OER in the alkaline electrolyte.This catalyst system can be easily fabricated via a low-temperature selenization of the solvothermal synthesized NiCo(OH)x precursor and the unique morphology of hybrid nanorods and nanoparticles was found by the electron microscopy analysis.The high valence state of the metal species was indicated by X-ray photoelectron spectroscopy study and a strong electronic effect was found in the NiSe_(2)-CoSe_(2)catalyst system compared to their counterparts.As a result,NiSe_(2)-CoSe_(2)exhibited high catalytic performance with a low overpotential of 250 mV to reach 10 mA·cm^(-2)for OER in the alkaline solution.Furthermore,high catalytic stability and catalytic kinetics were also observed.The superior performance can be attributed to the high valence states of Ni and Co and their strong synergetic coupling effect between the nanorods and nanoparticles,which could accelerate the charge transfer and offer abundant electrocatalytic active sites.The current work offers an efficient hetero-structure catalyst system for OER,and the results are helpful for the catalysis understanding.展开更多
Developing robust and efficient non-noble electrocatalysts for the hydrogen evolution reaction(HER)is paramount for sustainably producing hydrogen fuel from electrochemical water splitting.Engineering morphology and c...Developing robust and efficient non-noble electrocatalysts for the hydrogen evolution reaction(HER)is paramount for sustainably producing hydrogen fuel from electrochemical water splitting.Engineering morphology and chemical composition are significant for fabricating electrocatalysts with superior activity and durability.Herein,novel Ni-doped CoSe_(2)composites are prepared by a facile one-step hydrothermal method.The optimized 1T-phase Co_(0.75)Ni_(0.25)Se_(2)shows excellent HER performance,exhibiting overpotential of as low as 172 mV at 10 mA·cm^(–2) and a small Tafel slope of 32.4 mV·dec^(–1) in 0.5 mol·L^(-1) H_(2)SO_(4)solution,approaching that of com-mercial Pt/C electrocatalyst(30.7 mV·dec^(–1)).Furthermore,the electrocatalyst possesses superior long-term stability under acidic condition.Physicochemical measurements indicate that the homogeneous nanoparticles morphology,the unique electronic structure,and the 1T-phase are responsible for its superior HER performance.This work comes up with a promising strategy in synthesizing other earth-abundant and low-cost catalysts for industrial applications.展开更多
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
Cobalt selenide(CoSe_(2))has become a promising anode material for sodium-ion batteries(SIBs)due to its stable chemical properties,environmental friendliness,and high theoretical capacity.However,the undesirable rate ...Cobalt selenide(CoSe_(2))has become a promising anode material for sodium-ion batteries(SIBs)due to its stable chemical properties,environmental friendliness,and high theoretical capacity.However,the undesirable rate capacity and cycle stability of the anode materials largely limit its applications for SIBs due to the relatively low electronic conductivity and huge volume change during the Na+insertion/extraction.In this study,electrostatic spinning combined with a wet chemical method is employed to synthesize coral-like composite material(CNF@c-CoSe_(2)/C),which is composed of CoSe_(2)/carbon nanosheet arrays(CoSe_(2)/C)and carbon nanofibers(CNFs).CoSe_(2)/C nanoflakes derived from metal-organic frameworks(MOFs)with high surface area and the porous structure can inhibit the pulverization and amorphization of CoSe_(2) during charge and discharge processes,thus significantly keeping the stability of the microstructure.CNF can limit the overgrowth of nanosheets and serve as a conductive skeleton.Compared to two-dimensional CoSe_(2)/C nanoflakes and pure CoSe_(2) nanoparticles,the composite can expose more active sites and effectively accelerate the diffusion of Na+,which displays enhanced rate capability(266.5 mAh·g^(-1) at 5.0 A·g^(-1))and cycling stability(268.3 mAh·g^(-1) after 100 cycles at 1.0 A·g^(-1)).Moreover,the rational preparation strategy for metal selenide-based heterostructure material presents a new way for high-performance SIB s.展开更多
Water electrolysis is considered to be an effective and promising technology to make high-purity H_(2),however,the relationship between anion species and catalytic performance of electrocatalysts is still not complete...Water electrolysis is considered to be an effective and promising technology to make high-purity H_(2),however,the relationship between anion species and catalytic performance of electrocatalysts is still not completely clear.Herein,we report an anion engineering strategy to tune electrocatalytic water oxidation activity for Co-based materials.Novel hierarchical Co-based oxide/selenide/phosphide(Co-A,A = O,Se,P)hexagrams have been chosen as model materials.Electrochemical results and theoretical calculations reveal that the electron configuration,the electrical conductivity,and the oxidation potential of Co element in Co-A hexagrams could be moderated by the substitution of P atoms,which leads to the superior OER performance.Particularly,Co-P hexagram displays a low overpotential(η = 269 mV) at j = 10 mA/cm^(2) for the oxygen evolution reaction(OER) compared to Co-O hexagram(η = 399 m V) and Co-Se hexagram(η = 347 mV).This work is of great importance in understanding coordination atoms(O,Se and P)induced electrocatalytic properties of hierarchical Co-based materials.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 21675131, 21273174)the Municipal Science Foundation of Chongqing City (No. CSTC2015jcyjB50001)
文摘Hydrogen evolution reaction(HER) is a prospective method to generate pure hydrogen. The development of superior electrocatalysts based on earth-abundant materials, plays a critical role in the future.CoSe_2, one of the earth-abundant electrocatalysts, has been proved to be a promising catalyst for hydrogen generation. In our work, flower-like CoSe_2 nanorods with high quality are successfully synthesized through a facile ethylenediaminetetraacetic acid ligand(EDTA)-assisted hydrothermal process. The flower-like CoSe_2 nanorods show the brilliant electrochemical HER performance with 100 mA cm^(-2) at overpotential of 273 m V, a small Tafel slope of 35 mV dec^(-1) and strong durability in acid solution. The sparkly HER catalytic activity of CoSe_2 can be ascribed to its particular structure with large surface area and abundant active sites. Therefore, this work offers an outstanding candidate for improving hydrogen production capabilities by water electrolysis.
基金supported by the National Natural Science Foundation of China(52472194,52101243)the Natural Science Foundation of Guangdong Province,China(2023A1515012619,2025A1515012571,2025A1515010345)the Science and Technology Planning Project of Guangzhou(202201010565).
文摘Sodium-ion batteries are receiving more and more attention due to their low cost and abundant sodium storage capacity,and are considered to be a promising alternative to lithium-ion batteries.A large number of studies have shown that constructing heterostructures are considered an effective strategy to solve the hysteresis problem of electronic and ion dynamics in sodiumion battery anode materials.Herein,a nickel-cobalt bimetallic coordination polymer(NiCoCP)was synthesized using a coprecipitation method,and a CoSe_(2)@NiSe_(2) cross-stacked structure was obtained through high-temperature carbonization and selenization processes.CoSe_(2)@NiSe_(2) has a unique heterostructure and carbon film,which synergistically increases a large number of adsorption sites and alleviates the diffusion energy barrier,thereby improving the rapid diffusion kinetics of Na^(+)ions.It has superior rate performance and long-lasting cycle life.For sodium-ion batteries(SIBs),the specific capacity of CoSe_(2)@NiSe_(2) is around 460 mA h g^(-1) after 400 cycles at 1.0 A g^(-1).For potassium-ion batteries(PIBs),CoSe_(2)@NiSe_(2) also exhibits excellent cycling stability,maintaining a specific capacity of 160 mA h g^(-1) after 700 cycles at 1.0 A g^(-1).This study provides a new way to prepare metal selenide heterostructure as the promising anode material for SIBs.
基金financially supported by the National Natural Science Foundation of China (No.52371131)Beijing Nova Program (No.Z211100002121082)+2 种基金the Interdisciplinary Research Project for Young Teachers of University of Science and Technology Beijing (No.FRF-IDRY-21-013)the Project of State Key Laboratory of Explosion Science and Technology (No.QNKT23-05)Xiaomi Young Scholar Program。
文摘The highly reversible insertion/extraction of large-radius K^+into electrode materials remains a tough goal,especially for con version-type materials.Herein,we design a current collector-integrated electrode(N-CoSe/CoSe_(2)-C@Cu) as an advanced anode for potassium-ion battery(PIBs).The conductive CoSe/CoSe_(2) heterojunction with rich Se vacancy defects,conductive sp^2 N-doped carbon layer,and the elastic copper foil matrix can greatly accelerate the electron transfer and enhance the structural stability.Consequently,the well-designed N-CoSe/CoSe_(2)-C@Cu current collector-integrated electrode displays enhanced potassium storage performance with regard to a high capacity(325.1 mAh·g^(-1) at 0.1 A·g^(-1) after 200cycles),an exceptional rate capability(223.5 mAh·g^(-1) at2000 mA·g^(-1)),and an extraordinary long-term cycle stability(a capacity fading of only 0.019% per cycle over1200 cycles at 2000 mA·g^(-1)).Impressively,ex situ scanning electron microscopy(SEM) characterizations prove that the elastic structure of copper foil is merged into the cleverly designed N-CoSe/CoSe_(2)-C@Cu heterostructure,which buffers the deformation of structure and volume and greatly promotes the cycle life during the potassium/depotassium process.
基金financially supported by the Natural Science Foundation of Heilongjiang Province(No.LH2020B008)the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.2019DX13)+1 种基金China Postdoctoral Science Foundation(Nos.2016M600253 and 2017T100246)the Post-doctoral Foundation of Heilongjiang Province(No.LBH-Z16060)。
文摘Li-S battery has attracted great attention due to its high specific capacity and energy density.However,the serious polysulfides shuttle effect,low conductivity of sulfur and discharge product of lithium sulfide limit their application in commercial energy storage system.To solve the above problems,this work designs and constructs C@CoSe_(2) nano wire material as sulfur host for realizing high-performance Li-S battery.By combing the high conductivity,strong chemisorption,promising catalytic capacity and unique nanowire array structure,the C@CoSe_(2)/S electrode demonstrates a high specific capacity of 1264 mAh·g^(-1) with a low capacity decay of 0.051%per cycle at 0.2 C over 200 cycles.As expected,the battery delivers outstanding capacity retention over 1000 cycles at5 C and the decay is as low as≈0.026% per cycle.Moreover,even at higher sulfur loading of 5.1 mg·cm^(-2),the battery could still remain a stable areal capacity of 5.02 mAh·cm^(-2) at 0.2 C. More importantly,the experimental data and theoretical calculation results reveal that the internal mechanism of the improved electrochemical performance is the catalytic activation of CoSe_(2) on poly sulfides.
基金The work is supported by the National Natural Science Foundation of China(21972124)the Priority Academic Program Development of Jiangsu Higher Education Institution.the support of the Six Talent Peaks Project of Jiangsu Province(XCL-070-2018)。
文摘Hetero-structure induced high performance catalyst for oxygen evolution reaction(OER)in the water splitting reaction has received increased attention.Herein,we demonstrated a novel catalyst system of NiSe_(2)-CoSe_(2)consisting of nanorods and nanoparticles for the efficient OER in the alkaline electrolyte.This catalyst system can be easily fabricated via a low-temperature selenization of the solvothermal synthesized NiCo(OH)x precursor and the unique morphology of hybrid nanorods and nanoparticles was found by the electron microscopy analysis.The high valence state of the metal species was indicated by X-ray photoelectron spectroscopy study and a strong electronic effect was found in the NiSe_(2)-CoSe_(2)catalyst system compared to their counterparts.As a result,NiSe_(2)-CoSe_(2)exhibited high catalytic performance with a low overpotential of 250 mV to reach 10 mA·cm^(-2)for OER in the alkaline solution.Furthermore,high catalytic stability and catalytic kinetics were also observed.The superior performance can be attributed to the high valence states of Ni and Co and their strong synergetic coupling effect between the nanorods and nanoparticles,which could accelerate the charge transfer and offer abundant electrocatalytic active sites.The current work offers an efficient hetero-structure catalyst system for OER,and the results are helpful for the catalysis understanding.
基金financially supported by the National Natural Science Foundation of China (Nos. 52002254 and 51773049)the National Program for Support of Top-notch Young Professionals, China Aerospace Science and Technology Corporation-Harbin Institute of Technology Joint Center for Technology Innovation Fund (No. HIT15-1A01)+4 种基金Shanghai Academy of Spaceflight Technology Fund (No. SAST2017-126)the Scientific and Technological Cooperation and Development Fund (No. 2017KJHZ002)Sichuan Science and Technology Program (No. 2020YJ0262)Chunhui Plan of Ministry of Education of China, Fundamental Research Funds for the Central Universities, China (No. YJ201893)State Key Laboratory of Advanced Metals and Materials, China (No. 2019-Z03)。
文摘Developing robust and efficient non-noble electrocatalysts for the hydrogen evolution reaction(HER)is paramount for sustainably producing hydrogen fuel from electrochemical water splitting.Engineering morphology and chemical composition are significant for fabricating electrocatalysts with superior activity and durability.Herein,novel Ni-doped CoSe_(2)composites are prepared by a facile one-step hydrothermal method.The optimized 1T-phase Co_(0.75)Ni_(0.25)Se_(2)shows excellent HER performance,exhibiting overpotential of as low as 172 mV at 10 mA·cm^(–2) and a small Tafel slope of 32.4 mV·dec^(–1) in 0.5 mol·L^(-1) H_(2)SO_(4)solution,approaching that of com-mercial Pt/C electrocatalyst(30.7 mV·dec^(–1)).Furthermore,the electrocatalyst possesses superior long-term stability under acidic condition.Physicochemical measurements indicate that the homogeneous nanoparticles morphology,the unique electronic structure,and the 1T-phase are responsible for its superior HER performance.This work comes up with a promising strategy in synthesizing other earth-abundant and low-cost catalysts for industrial applications.
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financially supported by the National Natural Science Foundation of China(Nos.51603092 and 21706103)the Natural Science Foundation of Jiangsu Province(Nos.BK20160537 and BK20170549)China Postdoctoral Science Foundation(No.2019T120393)。
文摘Cobalt selenide(CoSe_(2))has become a promising anode material for sodium-ion batteries(SIBs)due to its stable chemical properties,environmental friendliness,and high theoretical capacity.However,the undesirable rate capacity and cycle stability of the anode materials largely limit its applications for SIBs due to the relatively low electronic conductivity and huge volume change during the Na+insertion/extraction.In this study,electrostatic spinning combined with a wet chemical method is employed to synthesize coral-like composite material(CNF@c-CoSe_(2)/C),which is composed of CoSe_(2)/carbon nanosheet arrays(CoSe_(2)/C)and carbon nanofibers(CNFs).CoSe_(2)/C nanoflakes derived from metal-organic frameworks(MOFs)with high surface area and the porous structure can inhibit the pulverization and amorphization of CoSe_(2) during charge and discharge processes,thus significantly keeping the stability of the microstructure.CNF can limit the overgrowth of nanosheets and serve as a conductive skeleton.Compared to two-dimensional CoSe_(2)/C nanoflakes and pure CoSe_(2) nanoparticles,the composite can expose more active sites and effectively accelerate the diffusion of Na+,which displays enhanced rate capability(266.5 mAh·g^(-1) at 5.0 A·g^(-1))and cycling stability(268.3 mAh·g^(-1) after 100 cycles at 1.0 A·g^(-1)).Moreover,the rational preparation strategy for metal selenide-based heterostructure material presents a new way for high-performance SIB s.
基金support from the National Natural Science Foundation of China (Nos.21808138, 21773146, 21975148 and21601118)Fok Ying-Tong Education Foundation for Outstanding Young Teachers in University+2 种基金China Postdoctoral Science Foundation (No.2019T120877)Fundamental Research Funds for the Central Universities (No.GK202103029)Young Talent Fund ofUniversity Association for Science and Technology in Shaanxi,China (No.20200602)。
文摘Water electrolysis is considered to be an effective and promising technology to make high-purity H_(2),however,the relationship between anion species and catalytic performance of electrocatalysts is still not completely clear.Herein,we report an anion engineering strategy to tune electrocatalytic water oxidation activity for Co-based materials.Novel hierarchical Co-based oxide/selenide/phosphide(Co-A,A = O,Se,P)hexagrams have been chosen as model materials.Electrochemical results and theoretical calculations reveal that the electron configuration,the electrical conductivity,and the oxidation potential of Co element in Co-A hexagrams could be moderated by the substitution of P atoms,which leads to the superior OER performance.Particularly,Co-P hexagram displays a low overpotential(η = 269 mV) at j = 10 mA/cm^(2) for the oxygen evolution reaction(OER) compared to Co-O hexagram(η = 399 m V) and Co-Se hexagram(η = 347 mV).This work is of great importance in understanding coordination atoms(O,Se and P)induced electrocatalytic properties of hierarchical Co-based materials.
