The rational design and construction of inexpensive and highly active electrocatalysts for hydrogen evolution reaction(HER)is of great importance for water splitting.Herein,we develop a facile approach for preparation...The rational design and construction of inexpensive and highly active electrocatalysts for hydrogen evolution reaction(HER)is of great importance for water splitting.Herein,we develop a facile approach for preparation of porous carbon-confined Ru-doped Cu nanoparticles(denoted as Ru-Cu@C)by direct pyrolysis of the Ru-exchanged Cu-BTC metal–organic framework.When served as the electrocatalyst for HER,strikingly,the obtained Ru-Cu@C catalyst exhibits an ultralow overpotential(only 20 mV at 10 mA cm^(-2))with a small Tafel slope of 37 m V dec^(-1)in alkaline electrolyte.The excellent performance is comparable or even superior to that of commercial Pt/C catalyst.Density functional theory(DFT)calculations confirm that introducing Ru atoms into Cu nanocrystals can significantly alter the desorption of H_(2) to achieve a close-to-zero hydrogen adsorption energy and thereby boost the HER process.This strategy gives a fresh impetus to explore low-cost and high-performance catalysts for HER in alkaline media.展开更多
The development of non-precious, high-efficient and durable electrocatalysts for H2 evolution in alkaline media is highly desirable. Herein we report NiCoP nanoleaves array vertically grown on Ni foam for H2 evolution...The development of non-precious, high-efficient and durable electrocatalysts for H2 evolution in alkaline media is highly desirable. Herein we report NiCoP nanoleaves array vertically grown on Ni foam for H2 evolution and overall water splitting via simple hydrothermal treatment and phosphorization. The selfsupported NiCoP nanoleaves architecture contributes to more exposed active sites, the smaller contact resistance between catalyst and substrate, faster ion diffusion and electron transfer. As a result, the optimized electrode requires only overpotentials of 98 and 173 mV to achieve current densities of 10 and100 m A cm-2 in 1.0 M KOH,respectively. Besides, used as both anode and cathode simultaneously, the electrode delivers current densities of 100 and 200 m A cm-2 at cell voltages of only 1.8 and 1.87 V, respectively. Moreover, the relatively high efficiency of about 11.4% for solar-driven water splitting further illustrates the application of our catalyst to sustainable development based on green technologies.展开更多
Developing non-noble-metal oxygen evolution reaction(OER) electrocatalysts with high performance is critical to electrocatalytic water splitting. In this work, we fabricated Co Fe-layered double hydroxide(LDH) nanowir...Developing non-noble-metal oxygen evolution reaction(OER) electrocatalysts with high performance is critical to electrocatalytic water splitting. In this work, we fabricated Co Fe-layered double hydroxide(LDH) nanowire arrays on graphite felt(Co Fe-LDH/GF) via a hydrothermal method. The Co Fe-LDH/GF, as a robust integrated 3 D OER anode, exhibits excellent catalytic activity with the need of low overpotential of 252 and 285 mV to drive current densities of 10 and 100 mA/cm^(2) in 1.0 mol/L KOH, respectively. In addition, it also maintains electrochemical durability for at least 24 h. This work would open up avenues for the development of GF like attractive catalyst supports for oxygen evolution applications.展开更多
太阳能驱动水裂解产氢是一种绿色能源技术,用于制备可再生和零碳排放燃料以实现可持续能源生产.近期,氮化碳(g-C_(3)N_(4))同素异形体C_(3)N_(5)的出现克服了g-C_(3)N_(4)的固有缺点,如光生载流子快速复合和可见光吸收差,而导致极低的...太阳能驱动水裂解产氢是一种绿色能源技术,用于制备可再生和零碳排放燃料以实现可持续能源生产.近期,氮化碳(g-C_(3)N_(4))同素异形体C_(3)N_(5)的出现克服了g-C_(3)N_(4)的固有缺点,如光生载流子快速复合和可见光吸收差,而导致极低的光催化效率.本文将硼掺杂剂通过原子替换或间隙掺杂的方式引入到C_(3)N_(5)体系中,并利用密度泛函理论对纯C_(3)N_(5)和硼掺杂C_(3)N_(5)体系进行计算,考察了硼原子对C_(3)N_(5)电子和光学性能的影响以及其催化析氢反应(HER)机理.热力学计算结果表明,硼原子掺杂在C_(3)N_(5)体系中是可行且有利的.在N_(3)位氮原子被硼原子取代(BN_(3)-C_(3)N_(5))后,带隙(0.6 e V)变窄.与纯C_(3)N_(5)相比,硼掺杂剂通过Volmer Tafel和Volmer Heyrovsky机制降低了酸性和碱性介质中HER反应中决定步骤的反应能垒.BN_(3)-C_(3)N_(5)表面的氢吸附吉布斯自由能(0.11 e V)与Pt/C催化剂(-0.09 e V)相当.综上,非金属掺杂碳可提高氮化物的催化性能,对未来该方向研究提供一定借鉴.展开更多
An effective strategy was proposed to control the formation of the interfacial bonding between Ru and molybdenum oxide support to stabilize the Ru atoms with the aim to enhance the hydrogen evolution reaction(HER)acti...An effective strategy was proposed to control the formation of the interfacial bonding between Ru and molybdenum oxide support to stabilize the Ru atoms with the aim to enhance the hydrogen evolution reaction(HER)activity of the resultant catalysts in alkaline medium.The different interfacial chemical bonds,including Ru–O,Ru–O–Mo,and mixed Ru–Mo/Ru–O–Mo,were prepared using an induced activation strategy by controlling the composition of reducing agents in the calcination process.And the regulation mechanism of the interfacial chemical bonds in molybdenum oxide supported Ru catalysts for optimizing HER activity was investigated by density functional theory(DFT)and experimental studies.We found that a controlled interfacial chemical Ru–O–Mo bonding in Ru-MoO_(2)/C manifests a 12-fold activity increase in catalyzing the hydrogen evolution reaction relative to the conventional metal/metal oxide catalyst(Ru-O-MoO_(2)/C).In a bifunctional effect,the interfacial chemical Ru-O-Mo sites promoted the dissociation of water and the production of hydrogen intermediates that were then adsorbed on the nearby Ru surfaces and recombined into molecular hydrogen.As compared,the nearby Ru surfaces in Ru–Mo bonding have weak adsorption capacity for the generation of these hydrogen intermediates,resulting in a 5-fold increase HER activity for Ru-Mo-MoO_(2)/C catalyst compared with Ru-O-MoO_(2)/C.展开更多
Non-noble metals such as Fe and Ni have comparable electrocatalytic activity and stability to that of Ir and Ru in an oxygen evolution reaction (OER). In this study, we synthesized carbon nanofibers with embedded FeNi...Non-noble metals such as Fe and Ni have comparable electrocatalytic activity and stability to that of Ir and Ru in an oxygen evolution reaction (OER). In this study, we synthesized carbon nanofibers with embedded FeNi composites (FeNi-CNFs) as OER electrocatalysts by a facile route comprising electrospinning and the pyrolysis of a mixture of metal precursors and a polymer solution. FeNi-CNFs demonstrated catalytic activity and stability that were better than that of 20 wt% Ir on Vulcan carbon black in oxidizing water to produce oxygen in an alkaline media. Physicochemical and electrochemical characterization revealed that Fe and Ni had synergistic roles that enhanced OER activity by the uniform formation and widening of pores in the carbon structure, while the CNF matrix also contributed to the increased stability of the catalyst.展开更多
基金the National Key R&D Program of China(2018YFB0605700)the National Natural Science Foundation of China(51778570,51879230,21725101,21871244,21521001,and 21703145)+1 种基金China Postdoctoral Science Foundation(2019TQ0298,2019M660151)Fujian Institute of Innovation(CAS)。
文摘The rational design and construction of inexpensive and highly active electrocatalysts for hydrogen evolution reaction(HER)is of great importance for water splitting.Herein,we develop a facile approach for preparation of porous carbon-confined Ru-doped Cu nanoparticles(denoted as Ru-Cu@C)by direct pyrolysis of the Ru-exchanged Cu-BTC metal–organic framework.When served as the electrocatalyst for HER,strikingly,the obtained Ru-Cu@C catalyst exhibits an ultralow overpotential(only 20 mV at 10 mA cm^(-2))with a small Tafel slope of 37 m V dec^(-1)in alkaline electrolyte.The excellent performance is comparable or even superior to that of commercial Pt/C catalyst.Density functional theory(DFT)calculations confirm that introducing Ru atoms into Cu nanocrystals can significantly alter the desorption of H_(2) to achieve a close-to-zero hydrogen adsorption energy and thereby boost the HER process.This strategy gives a fresh impetus to explore low-cost and high-performance catalysts for HER in alkaline media.
基金the financial support from the Changsha Science and Technology Plan(kq1801065)Hunan Provincial Science and Technology Plan Project(No.2017TP1001)+1 种基金state Key Laboratory Fundthe postdoctoral research funding plan in Central South University(Grant No.140050022)。
文摘The development of non-precious, high-efficient and durable electrocatalysts for H2 evolution in alkaline media is highly desirable. Herein we report NiCoP nanoleaves array vertically grown on Ni foam for H2 evolution and overall water splitting via simple hydrothermal treatment and phosphorization. The selfsupported NiCoP nanoleaves architecture contributes to more exposed active sites, the smaller contact resistance between catalyst and substrate, faster ion diffusion and electron transfer. As a result, the optimized electrode requires only overpotentials of 98 and 173 mV to achieve current densities of 10 and100 m A cm-2 in 1.0 M KOH,respectively. Besides, used as both anode and cathode simultaneously, the electrode delivers current densities of 100 and 200 m A cm-2 at cell voltages of only 1.8 and 1.87 V, respectively. Moreover, the relatively high efficiency of about 11.4% for solar-driven water splitting further illustrates the application of our catalyst to sustainable development based on green technologies.
基金supported by the National Natural Science Foundation of China (No.22072015)。
文摘Developing non-noble-metal oxygen evolution reaction(OER) electrocatalysts with high performance is critical to electrocatalytic water splitting. In this work, we fabricated Co Fe-layered double hydroxide(LDH) nanowire arrays on graphite felt(Co Fe-LDH/GF) via a hydrothermal method. The Co Fe-LDH/GF, as a robust integrated 3 D OER anode, exhibits excellent catalytic activity with the need of low overpotential of 252 and 285 mV to drive current densities of 10 and 100 mA/cm^(2) in 1.0 mol/L KOH, respectively. In addition, it also maintains electrochemical durability for at least 24 h. This work would open up avenues for the development of GF like attractive catalyst supports for oxygen evolution applications.
文摘太阳能驱动水裂解产氢是一种绿色能源技术,用于制备可再生和零碳排放燃料以实现可持续能源生产.近期,氮化碳(g-C_(3)N_(4))同素异形体C_(3)N_(5)的出现克服了g-C_(3)N_(4)的固有缺点,如光生载流子快速复合和可见光吸收差,而导致极低的光催化效率.本文将硼掺杂剂通过原子替换或间隙掺杂的方式引入到C_(3)N_(5)体系中,并利用密度泛函理论对纯C_(3)N_(5)和硼掺杂C_(3)N_(5)体系进行计算,考察了硼原子对C_(3)N_(5)电子和光学性能的影响以及其催化析氢反应(HER)机理.热力学计算结果表明,硼原子掺杂在C_(3)N_(5)体系中是可行且有利的.在N_(3)位氮原子被硼原子取代(BN_(3)-C_(3)N_(5))后,带隙(0.6 e V)变窄.与纯C_(3)N_(5)相比,硼掺杂剂通过Volmer Tafel和Volmer Heyrovsky机制降低了酸性和碱性介质中HER反应中决定步骤的反应能垒.BN_(3)-C_(3)N_(5)表面的氢吸附吉布斯自由能(0.11 e V)与Pt/C催化剂(-0.09 e V)相当.综上,非金属掺杂碳可提高氮化物的催化性能,对未来该方向研究提供一定借鉴.
基金supports by the National Natural Science Foundation of China(No.21978126).
文摘An effective strategy was proposed to control the formation of the interfacial bonding between Ru and molybdenum oxide support to stabilize the Ru atoms with the aim to enhance the hydrogen evolution reaction(HER)activity of the resultant catalysts in alkaline medium.The different interfacial chemical bonds,including Ru–O,Ru–O–Mo,and mixed Ru–Mo/Ru–O–Mo,were prepared using an induced activation strategy by controlling the composition of reducing agents in the calcination process.And the regulation mechanism of the interfacial chemical bonds in molybdenum oxide supported Ru catalysts for optimizing HER activity was investigated by density functional theory(DFT)and experimental studies.We found that a controlled interfacial chemical Ru–O–Mo bonding in Ru-MoO_(2)/C manifests a 12-fold activity increase in catalyzing the hydrogen evolution reaction relative to the conventional metal/metal oxide catalyst(Ru-O-MoO_(2)/C).In a bifunctional effect,the interfacial chemical Ru-O-Mo sites promoted the dissociation of water and the production of hydrogen intermediates that were then adsorbed on the nearby Ru surfaces and recombined into molecular hydrogen.As compared,the nearby Ru surfaces in Ru–Mo bonding have weak adsorption capacity for the generation of these hydrogen intermediates,resulting in a 5-fold increase HER activity for Ru-Mo-MoO_(2)/C catalyst compared with Ru-O-MoO_(2)/C.
文摘Non-noble metals such as Fe and Ni have comparable electrocatalytic activity and stability to that of Ir and Ru in an oxygen evolution reaction (OER). In this study, we synthesized carbon nanofibers with embedded FeNi composites (FeNi-CNFs) as OER electrocatalysts by a facile route comprising electrospinning and the pyrolysis of a mixture of metal precursors and a polymer solution. FeNi-CNFs demonstrated catalytic activity and stability that were better than that of 20 wt% Ir on Vulcan carbon black in oxidizing water to produce oxygen in an alkaline media. Physicochemical and electrochemical characterization revealed that Fe and Ni had synergistic roles that enhanced OER activity by the uniform formation and widening of pores in the carbon structure, while the CNF matrix also contributed to the increased stability of the catalyst.
