CoN/NiMoN异质结的构建及其碱性析氢性能研究

Construction and Alkaline Hydrogen Evolution Performance of CoN/NiMoN Heterostructure

目前,世界各国都在积极发展新型清洁能源。电解水制氢是一种新的清洁能源技术,具有广阔的应用前景。为了降低能源消耗,提高电解水技术的实用性,人们一直在探索高性能的电催化剂。结合水热法与电沉积法,利用氨气热处理法,设计出一种新颖的CoN/NiMoN异质结电催化剂,成功实现了非晶态纳米绒毛状CoN在NiMoN纳米棒上的负载。研究发现,NiMoN的电子结构在与CoN结合后发生了转变,Ni原子的电子向Mo、N转移从而使NiMoN表面活性位点的电子结构得到有效调控。此外,构筑CoN/NiMoN异质结的构筑增大了催化剂电化学活性面积及其催化位点的本征活性,从而进一步提升了催化性能。与原始的NiMoN、NiMoO_(4)相比,负载CoN后的NiMoN表现出较强的析氢反应(HER)性能,在-0.5Vvs.RHE电势下的电流密度分别为原来的1.58倍和4.66倍,并且只需要48mV、226mV的过电位就可以达到10mA·cm^(-2)、100mA·cm^(-2)的电流密度,其催化性能足以媲美相应的贵金属催化剂。

At present,countries all over the world are actively developing new clean energy sources.Hydrogen production through electrolysis of water is a sustainable clean energy technology with broad application prospects.In order to reduce energy consumption and improve the practicality of electrolysis technology,researchers have made great efforts to explore high-performance electrocatalysts.A novel CoN/NiMoN heterostructure electrocatalyst was designed by combining hydrothermal and electrodeposition methods,combined with ammonia heat treatment approach.Amorphous nanofibrous CoN was successfully loaded onto NiMoN nanorods.It is found that the electronic structure of NiMoN was changed after combining with CoN.The electrons transferred from Ni to Mo and N,which effectively regulated the electronic structure of the active sites on the surface of NiMoN.Furthermore,the formation of the CoN/NiMoN heterostructure increased the electrochemical active surface area and intrinsic activity of the catalytic sites,thereby further enhancing the catalytic performance.Compared with pristine NiMoN and NiMoO_(4),the CoN-loaded NiMoN exhibited significantly improved hydrogen evolution reaction(HER)performance,with current densities at−0.5 V vs.RHE to be increased by 1.58 times and 4.66 times,respectively.The overpotentials at current densities of 10 and 100 mA·cm^(−2)were only 48 and 226 mV,respectively.The catalytic performance of CoN/NiMoN is comparable with that of the commonly used noble metal catalysts.