Mechanistic studies of oxygen reduction and evolution reactions on Ni3S2 surfaces.

The Ni 3 S 2 (100) surface exhibits promising bifunctional catalytic activity towards ORR and OER. Most important of all, the ORR catalytic activity of Ni 3 S 2 (100) can be enhanced by the doping of Cu, and the OER catalytic activity of Ni 3 S 2 (100) can be improved by the doping of Se. [Display omitted] • Ni 3 S 2 (100) exhibits bifunctional catalytic activity towards ORR and OER. • The ORR catalytic activity of Ni 3 S 2 (100) can be enhanced by the doping of Cu. • The OER catalytic activity of Ni 3 S 2 (100) can be improved by the doping of Se. • A descriptor derived from the electron affinity was developed. 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 Ni 3 S 2 was investigated based on density functional theory. It was found that the Ni 3 S 2 (100) surface exhibits promising bifunctional catalytic activity towards the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). The ORR catalytic activity of Ni 3 S 2 (100) can be enhanced by the doping of Cu, and the OER catalytic activity of Ni 3 S 2 (100) can be improved by the doping of Se. Furthermore, a descriptor derived from the electron affinity was developed, which correlate Ni 3 S 2 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. [ABSTRACT FROM AUTHOR]