Zheng Xiuzhang, Sun Aowei, Qiu Yanling, Wang Zixuan, Xu Jiangtao, Liu Jingquan
College of Materials Science and Engineering, Institute for Graphene Applied Technology Innovation, Qingdao University, Qingdao 266071, China.
College of Materials Science and Engineering, Institute for Graphene Applied Technology Innovation, Qingdao University, Qingdao 266071, China.
J Colloid Interface Sci. 2023 Nov 15;650(Pt B):1966-1973. doi: 10.1016/j.jcis.2023.07.131. Epub 2023 Jul 22.
Adjusting the electronic structure and intrinsic activity of the active site of the catalyst based on atomic implantation is the crucial to realizing efficient electrochemical water splitting in alkaline media. Thus, we introduce vanadium (V) atoms with abundant vacant d orbitals as dopants into nickel selenides (NiSe), which has abundant variable valence states, and successfully synthesise three-dimensional bi-functional catalysts self-supported on Ni foam (NF). The electron structure characterisation reveals that, compared with the pure NiSe phase, the oxidation states of Ni cations and electron concentration at the Se site in V-NiSe increase due to the V doping. These changes are accompanied by changes in the electronic structure and active sites in V-NiSe. The as-generated V-NiSe nanorods exhibit an optimised electronic structure, high number of active sites and highly rough nanorod array structure with large electrochemically active surface area and in situ growth characteristics of conductive NF. Thus, the as-generated V-NiSe nanorods catalysts exhibit excellent bi-functional catalytic activity, with 50 mA⋅cm at an overpotential of 270.2 and 251.2 mV for oxygen evolution reactions (OER) and hydrogen evolution reactions (HER), respectively, in KOH (1 M). Water electrolysis using V-NiSe as both the anode and cathode requires a cell voltage of 1.76 V to drive 50 mA⋅cm, continuously operating for 80 h. This study provides a systematic understanding of the design of transition-metal catalysts using heteroatomic doping to control their electronic structure and catalytic activity.
基于原子注入调节催化剂活性位点的电子结构和本征活性是在碱性介质中实现高效电化学水分解的关键。因此，我们将具有丰富空d轨道的钒（V）原子作为掺杂剂引入具有丰富可变价态的硒化镍（NiSe）中，并成功合成了自支撑在泡沫镍（NF）上的三维双功能催化剂。电子结构表征表明，与纯NiSe相相比，由于V掺杂，V-NiSe中Ni阳离子的氧化态和Se位点的电子浓度增加。这些变化伴随着V-NiSe中电子结构和活性位点的变化。生成的V-NiSe纳米棒表现出优化的电子结构、大量的活性位点以及具有大电化学活性表面积和导电NF原位生长特性的高度粗糙的纳米棒阵列结构。因此，生成的V-NiSe纳米棒催化剂表现出优异的双功能催化活性，在1 M KOH中，析氧反应（OER）和析氢反应（HER）的过电位分别为270.2和251.2 mV时，电流密度为50 mA·cm²。使用V-NiSe作为阳极和阴极的水电解需要1.76 V的电池电压来驱动50 mA·cm²，连续运行80小时。这项研究为利用杂原子掺杂控制过渡金属催化剂的电子结构和催化活性的设计提供了系统的理解。
