Optimizing Surface State Electrons of Topological Semi‐Metal by Atomic Doping for Enhanced Hydrogen Evolution Reaction
Meixia Su, Yuhao Zhang, Guo Liu, Haiqing Jiang, Yuan Lin, Yan Ding, Qingfeng Wu, Wei Wei, Xinge Wang, Tianyu Wu, Kun Tao, Changcheng Chen, Erqing Xie, Zhenxing Zhang
Abstract
Abstract Topological materials carrying topological surface states (TSSs) have extraordinary carrier mobility and robustness, which provide a new platform for searching for efficient hydrogen evolution reaction (HER) electrocatalysts. However, the majority of these TSSs originate from the sp band of topological quantum catalysts rather than the d band. Here, based on the density functional theory calculation, it is reported a topological semimetal Pd 3 Sn carrying TSSs mainly derived from d orbital and proposed that optimizing surface state electrons of Pd 3 Sn by introduction heteroatoms (Ni) can promote hybridization between hydrogen atoms and electrons, thereby reducing the Gibbs free energy ( ΔG H ) of adsorbed hydrogen and improving its HER performance. Moreover, this is well verified by electrocatalytic experiment results, the Ni‐doped Pd 3 Sn (Ni 0.1 Pd 2.9 Sn) show much lower overpotential (−29 mV vs RHE) and Tafel slope (17 mV dec −1 ) than Pd 3 Sn (−39 mV vs RHE, 25 mV dec −1 ) at a current density of 10 mA cm −2 . Significantly, the Ni 0.1 Pd 2.9 Sn nanoparticles exhibit excellent stability for HER. The electrocatalytic activity of Ni 0.1 Pd 2.9 Sn nanoparticles is superior to that of commercial Pt. This work provides an accurate guide for manipulating surface state electrons to improve the HER performance of catalysts.