A lithium-sulfur(Li-S)system is an important candidate for future lithium-ion system due to its low cost and high specific theoretical capacity(1675 m Ah/g,2600 Wh/kg),which is greatly hindered by the poor conductivit...A lithium-sulfur(Li-S)system is an important candidate for future lithium-ion system due to its low cost and high specific theoretical capacity(1675 m Ah/g,2600 Wh/kg),which is greatly hindered by the poor conductivity of sulfur,large volume change and dissolution of lithium polysulfides.Two-dimensional(2D)materials with monolayers or few-layers usually have peculiar structures and physical/chemical properties,which can resolve the critical issues in Li-S batteries.Especially,the metal-based 2D nanomaterials,including ferrum,cobalt or other metal-based composites with various anions,can provide high conductivity,large surface area and abundant reaction sites for restraining the diffusion for lithium polysulfides.In this mini-review,we will present an overview of recent developments on metal-based 2D nanomaterials with various anions as the electrode materials for Li-S batteries.Since the main bottleneck for the Li-S system is the shuttle of polysulfides,emphasis is placed on the structure and components,physical/chemical interaction and interaction mechanisms of the 2D materials.Finally,the challenges and prospects of metal-based 2D nanomaterials for Li-S batteries are discussed and proposed.展开更多
Transition metal hydroxides/oxyhydroxides have recently emerged as highly active electrocatalysts for oxygen evolution reaction in alkaline water electrolysis,while have not yet been widely investigated for hydrogen e...Transition metal hydroxides/oxyhydroxides have recently emerged as highly active electrocatalysts for oxygen evolution reaction in alkaline water electrolysis,while have not yet been widely investigated for hydrogen evolution electrocatalysts owing to their unfavorable H*-adsorption,making it difficult to construct an overall-water-splitting cell for hydrogen production.In this work,we proposed a straightforward and effective approach to develop an efficient in-plane heterostructured CoOOH/Co(OH)_(2) catalyst via in-situ electrochemical dehydrogenation method,in which the dehydrogenated–CoOOH and Co(OH)_(2) at the surface synergistically boost the hydrogen evolution reaction(HER)kinetics in base as confirmed by high-resolution transmission electron microscope,synchrotron X-ray absorption spectroscopy,and electron energy loss spectroscopy.Due to the in-situ dehydrogenation of ultrathin Co(OH)_(2) nanosheets,the catalytic activity of the CoOOH/Co(OH)_(2) heterostructures is progressively improved,which exhibit outstanding hydrogen-evolving activity in base requiring a low overpotential of 132 m V to afford 10 m A/cm^(2)with very fast reaction kinetics after 60 h dehydrogenation.The gradually improved catalytic performance for the CoOOH/Co(OH)2is probably due to the enhanced H*-adsorption induced by the synergistic effect of heterostructures and better conductivity of Co OOH relative to electrically insulating Co(OH)_(2).This work will open the opportunity for a new family of transition metal hydroxides/oxyhydroxides as active HER catalysts,and also highlight the importance of using in situ techniques to construct precious metal-free efficient catalysts for alkaline hydrogen evolution.展开更多
The design of high-efficiency non-noble and earth-abundant electrocatalysts for hydrogen evolution reaction(HER)is highly paramount for water splitting and renewable energy systems.Molybdenum disulfide(MoS_(2))with ab...The design of high-efficiency non-noble and earth-abundant electrocatalysts for hydrogen evolution reaction(HER)is highly paramount for water splitting and renewable energy systems.Molybdenum disulfide(MoS_(2))with abundant edge sites can be utilized as a promising alternative,but its catalytic activity is greatly related to the pH values,especially in an alkaline environment due to the extremely high energy barriers for water adsorption and dissociation steps.Here we report an exceptionally efficient and stable electrocatalyst to improve the sluggish HER process of layered MoS_(2)particles in different pH electrolytes,especially in base.The electrocatalyst is constructed by in situ growing selenium-doped MoS_(2)(Se-MoS_(2))nanoparticles on three-dimensional cobalt nickel diselenide(mCo_(0.2)Ni_(0.8)Se_(2))nanostructured arrays.Due to the large number of active edge sites of Se-MoS_(2)particles exposed at the surface,robust electrical conductivity and large surface area of mCo_(0.2)Ni_(0.8)Se_(2)support,and strong interfacial interactions between Se-MoS_(2)and mCo_(0.2)Ni_(0.8)Se_(2),this hybrid catalyst shows very outstanding catalytic HER properties featured by low overpotentials of 30 and 122 mV at 10 and 100 mA/cm^(2)with good operational stability in base,respectively,which outperforms most of inexpensive catalysts consisting of layered MoS_(2),transition metal selenides and sulfides,and it performs as well as noble Pt catalysts.Meanwhile,this electrocatalyst is also very active in neutral and acidic electrolytes,requiring low overpotentials of 93 and 94 mV at 10 mA/cm^(2),respectively,demonstrating its superb pH universality as a HER electrocatalyst with excellent catalytic durability.This study provides a straightforward strategy to construct an efficient non-noble electrocatalyst for driving the HER kinetics in different electrolytes.展开更多
电解水是绿氢制备最有希望的路线之一,它的颈瓶是阳极析氧反应需要极高的过电位,导致电解水制氢整体能耗高.因此,迫切需要开发廉价、高活性、大电流稳定的非贵金属基多功能催化剂以期降低电解水的制氢能耗,如淡水或含尿素的水.鉴于此,...电解水是绿氢制备最有希望的路线之一,它的颈瓶是阳极析氧反应需要极高的过电位,导致电解水制氢整体能耗高.因此,迫切需要开发廉价、高活性、大电流稳定的非贵金属基多功能催化剂以期降低电解水的制氢能耗,如淡水或含尿素的水.鉴于此,我们合理设计并合成了绣球状的CoP/Ni3FeN异质结,用于碱性析氢、析氧和尿素电催化氧化反应.该催化剂呈现出优异的三功能催化活性和出色的大电流耐久性,在进行析氢、析氧和尿素电氧化反应时,分别需要-0.160、1.538和1.419 V的超低电位就能达到1000 mA cm^(-2)的高电流密度.此外,将该电催化剂作为正极和负极耦合全解水/尿素器件,仅需要1.577/1.668 V的电压就能驱动500 mA cm^(-2).此外,结合原位拉曼光谱、测试后的X射线光电子能谱分析与密度泛函理论计算,我们验证了CoP/Ni3FeN异质结催化剂可以极大地促进析氧和尿素氧化反应中的活性物种金属羟基氧化物的形成,同时降低析氢反应中的水吸附和活性氢中间体的吸附能垒,从而协同促进高效的析氢、析氧和尿素电催化氧化性能.这项工作为开发多功能电催化剂用于低电压电化学制氢提供了一条有效途径.展开更多
基金supported by National Natural Science Foundation of China(No.52172197)the Joint Funds of the National Natural Science Foundation of China(No.U1865207)+5 种基金Science and Technology Innovation Platform(No.2018RS3070)Hundred Youth Talents Programs of Hunan ProvincePhD Start-up Foundation of Hengyang Normal University(No.19QD10)Scientific Research Fund of Hunan Provincial Education Department(No.20A062)the support from Hunan joint international laboratory of advanced materials and technology for clean energy(No.2020CB1007)the Science and Technology Innovation Program of Hunan Province(No.2016TP1020)。
文摘A lithium-sulfur(Li-S)system is an important candidate for future lithium-ion system due to its low cost and high specific theoretical capacity(1675 m Ah/g,2600 Wh/kg),which is greatly hindered by the poor conductivity of sulfur,large volume change and dissolution of lithium polysulfides.Two-dimensional(2D)materials with monolayers or few-layers usually have peculiar structures and physical/chemical properties,which can resolve the critical issues in Li-S batteries.Especially,the metal-based 2D nanomaterials,including ferrum,cobalt or other metal-based composites with various anions,can provide high conductivity,large surface area and abundant reaction sites for restraining the diffusion for lithium polysulfides.In this mini-review,we will present an overview of recent developments on metal-based 2D nanomaterials with various anions as the electrode materials for Li-S batteries.Since the main bottleneck for the Li-S system is the shuttle of polysulfides,emphasis is placed on the structure and components,physical/chemical interaction and interaction mechanisms of the 2D materials.Finally,the challenges and prospects of metal-based 2D nanomaterials for Li-S batteries are discussed and proposed.
基金mainly funded by National Science Foundation of China(Nos.12074116 and 52172197)the Youth 1000 Talent Program of China,Undergraduate Scientific Research Innovation Project of China(No.202110542037)+3 种基金Science and Technology Innovation Platform(No.2019RS1032)Major Program of Natural Science Foundation of Hunan Province of Hunan Province,and Hunan Normal University(Nos.2021133,21CSZ004 and 21CSZ029)the support from Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy(No.2020CB1007)the support from Science and Technology Innovation Program of Hunan Province(No.2021RC2075)。
文摘Transition metal hydroxides/oxyhydroxides have recently emerged as highly active electrocatalysts for oxygen evolution reaction in alkaline water electrolysis,while have not yet been widely investigated for hydrogen evolution electrocatalysts owing to their unfavorable H*-adsorption,making it difficult to construct an overall-water-splitting cell for hydrogen production.In this work,we proposed a straightforward and effective approach to develop an efficient in-plane heterostructured CoOOH/Co(OH)_(2) catalyst via in-situ electrochemical dehydrogenation method,in which the dehydrogenated–CoOOH and Co(OH)_(2) at the surface synergistically boost the hydrogen evolution reaction(HER)kinetics in base as confirmed by high-resolution transmission electron microscope,synchrotron X-ray absorption spectroscopy,and electron energy loss spectroscopy.Due to the in-situ dehydrogenation of ultrathin Co(OH)_(2) nanosheets,the catalytic activity of the CoOOH/Co(OH)_(2) heterostructures is progressively improved,which exhibit outstanding hydrogen-evolving activity in base requiring a low overpotential of 132 m V to afford 10 m A/cm^(2)with very fast reaction kinetics after 60 h dehydrogenation.The gradually improved catalytic performance for the CoOOH/Co(OH)2is probably due to the enhanced H*-adsorption induced by the synergistic effect of heterostructures and better conductivity of Co OOH relative to electrically insulating Co(OH)_(2).This work will open the opportunity for a new family of transition metal hydroxides/oxyhydroxides as active HER catalysts,and also highlight the importance of using in situ techniques to construct precious metal-free efficient catalysts for alkaline hydrogen evolution.
基金This project has been partially supported by THE Science and Technology Innovation Platform(Nos.2018RS3070,2019RS1032)Hundred Youth Talents Programs of Hunan Province,and the'XiaoXiang Scholar'Talents Foundation of Hunan Normal Univer-sity in Changsha of P.R.China+2 种基金This project also acknowledges the supports from the Postgraduate Scientific Research Innovation Project of Hunan Province(No.CX20200519)instrumental analy-sis funds provided by Hunan Normal University(20CSY095,20CSY096)the National Science Foundation of China(Nos.11704109,51801059).
文摘The design of high-efficiency non-noble and earth-abundant electrocatalysts for hydrogen evolution reaction(HER)is highly paramount for water splitting and renewable energy systems.Molybdenum disulfide(MoS_(2))with abundant edge sites can be utilized as a promising alternative,but its catalytic activity is greatly related to the pH values,especially in an alkaline environment due to the extremely high energy barriers for water adsorption and dissociation steps.Here we report an exceptionally efficient and stable electrocatalyst to improve the sluggish HER process of layered MoS_(2)particles in different pH electrolytes,especially in base.The electrocatalyst is constructed by in situ growing selenium-doped MoS_(2)(Se-MoS_(2))nanoparticles on three-dimensional cobalt nickel diselenide(mCo_(0.2)Ni_(0.8)Se_(2))nanostructured arrays.Due to the large number of active edge sites of Se-MoS_(2)particles exposed at the surface,robust electrical conductivity and large surface area of mCo_(0.2)Ni_(0.8)Se_(2)support,and strong interfacial interactions between Se-MoS_(2)and mCo_(0.2)Ni_(0.8)Se_(2),this hybrid catalyst shows very outstanding catalytic HER properties featured by low overpotentials of 30 and 122 mV at 10 and 100 mA/cm^(2)with good operational stability in base,respectively,which outperforms most of inexpensive catalysts consisting of layered MoS_(2),transition metal selenides and sulfides,and it performs as well as noble Pt catalysts.Meanwhile,this electrocatalyst is also very active in neutral and acidic electrolytes,requiring low overpotentials of 93 and 94 mV at 10 mA/cm^(2),respectively,demonstrating its superb pH universality as a HER electrocatalyst with excellent catalytic durability.This study provides a straightforward strategy to construct an efficient non-noble electrocatalyst for driving the HER kinetics in different electrolytes.
基金supported by the National Natural Science Foundation of China (52172197 and 22063001)the Youth 1000 Talent Program of China+2 种基金the Major Projects “Takes the lead” of Natural Science Foundation (2021JC0008)the Postgraduate Scientific Research Innovation Project of Hunan Province (QL 20220113)the Interdisciplinary Research Program (2023JC201) of Hunan Normal University in Changsha, China。
文摘电解水是绿氢制备最有希望的路线之一,它的颈瓶是阳极析氧反应需要极高的过电位,导致电解水制氢整体能耗高.因此,迫切需要开发廉价、高活性、大电流稳定的非贵金属基多功能催化剂以期降低电解水的制氢能耗,如淡水或含尿素的水.鉴于此,我们合理设计并合成了绣球状的CoP/Ni3FeN异质结,用于碱性析氢、析氧和尿素电催化氧化反应.该催化剂呈现出优异的三功能催化活性和出色的大电流耐久性,在进行析氢、析氧和尿素电氧化反应时,分别需要-0.160、1.538和1.419 V的超低电位就能达到1000 mA cm^(-2)的高电流密度.此外,将该电催化剂作为正极和负极耦合全解水/尿素器件,仅需要1.577/1.668 V的电压就能驱动500 mA cm^(-2).此外,结合原位拉曼光谱、测试后的X射线光电子能谱分析与密度泛函理论计算,我们验证了CoP/Ni3FeN异质结催化剂可以极大地促进析氧和尿素氧化反应中的活性物种金属羟基氧化物的形成,同时降低析氢反应中的水吸附和活性氢中间体的吸附能垒,从而协同促进高效的析氢、析氧和尿素电催化氧化性能.这项工作为开发多功能电催化剂用于低电压电化学制氢提供了一条有效途径.
