Development of a Ni-Doped VAl<sub>3</sub> Topological Semimetal with a Significantly Enhanced HER Catalytic Performance
Xiangpeng Kong, Tao Jiang, Jiaojiao Gao, Xianbiao Shi, Jian Shao, Yunhuan Yuan, Hua‐Jun Qiu, Weiwei Zhao
Abstract
Topological materials with robust topological surface states appear to be well-suited as electrochemical catalysts. However, few studies have been published on the development of non-noble metal topological catalysts, most likely because the topological properties tend to be attributed to the s and p orbital electrons, while transition-metal catalysis mainly involves d orbital electrons. Herein, we proposed a topological semimetallic (TSM) compound, VAl3, with a surface state consisting mainly of d orbital electrons, as an electrocatalyst for the hydrogen evolution reaction (HER). Density functional theory (DFT) calculations showed that the surface state electrons enhanced the adsorption of H atoms. Moreover, the transfer of surface state electrons between the surface and adsorbed H atoms was optimized through nickel doping. We experimentally prepared single-crystals VAl3 and V0.75Ni0.25Al3 alloys. Electrochemical analysis showed that not only did V0.75Ni0.25Al3 outperform VAl3 but also it was among the best non-noble metal topological HER electrocatalysts currently available.