Regulating the Local Spin State and Band Structure in Ni<sub>3</sub>S<sub>2</sub> Nanosheet for Improved Oxygen Evolution Activity
Zongpeng Wang, Shijie Shen, Zhiping Lin, Weiying Tao, Qinghua Zhang, Fanqi Meng, Lin Gu, Wenwu Zhong
Abstract
Abstract The separate modulation of the adsorption of *O and *OOH is challenging in oxygen evolution reaction (OER), which results in a large overpotential and slow kinetics. To balance the adsorption of the two active species, here, a way to regulate the local spin state and band structure simultaneously in Ni 3 S 2 nanosheets is reported. The adequate doping of W heteroatoms causes the electron depletion from the Ni active site, which modulates the spin state of e g electrons, weakening the adsorption of *O. Additionally, the introduction of S vacancies contributes to the upshift of the d band center, which strengthens the adsorption of *OOH. In this manner, the adsorption of Ni 3 S 2 for the active intermediates is optimized, resulting in a considerably improved overpotential of 246 mV at 100 mA cm −2 and a Tafel slope of 66 mV dec −1 . This work provides insights into the exploration of OER catalysts through synergistic modulation of the spin state and the band structure.