Manipulating electronic regulation of nickel sulfide for boosting water oxidation
Xiang Ding, Luyu Liu, Mingquan Liu, Hongli Liu, Jun Xiang, Jianling Dong, Yamei Zhang, Nan Jiang, Yin Yin, Fuzhan Song
Abstract
The development of non-precious metal oxygen evolution reaction (OER) electrocatalysts is of critical for industrial-scale hydrogen production, but remains challenging. In this work, we report a novel Bi-doped nickel sulfide (Bi–Ni 3 S 2 ). The incorporation of Bi dopant not only induces the oxidation of d-orbital electrons of Ni, but also decreases the electron population in e-orbitals, thereby optimizing the electronic reconfiguration of Ni 3 S 2 . In-situ Raman spectroscopy further reveals that Bi dopant could manipulate local electronic micro-environment of Ni sites in Ni 3 S 2 -based electrocatalysts through orbital hybridization, thereby promoting the formation of high valent hydroxyl oxides. The optimized Bi–Ni 3 S 2 catalyst exhibits superior catalytic performance, achieving a current density of 10 and 500 mA cm −2 at an overpotential of only 256 and 328 mV in 1.0 M KOH. Importantly, an assembled electrolyzer merely requires 2.08 V to deliver an industrial-grade current density of 1000 A cm −2 while maintaining stable operation for over 200 h.