Mechanistic studies of oxygen reduction and evolution reactions on Ni3S2 surfaces

Developing highly efficient and nonprecious electrocatalysts for oxygen-involving energy conversion reactions is crucial for the development of clean and sustainable energy technologies. Herein, the intrinsic relationship between the atomic structure and the catalytic activity of Ni3S2 was investigated based on density functional theory. It was found that the Ni3S2 (100) surface exhibits promising bifunctional catalytic activity towards the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). The ORR catalytic activity of Ni3S2 (100) can be enhanced by the doping of Cu, and the OER catalytic activity of Ni3S2 (100) can be improved by the doping of Se. Furthermore, a descriptor derived from the electron affinity was developed, which correlate Ni3S2 microstructures with their catalytic activities. This study provides a systematic understanding to the intrinsic activity of transition metal sulfides, paving the way to the rational design and development of advanced electrocatalysts for renewable energy technology.