Theoretical Understanding of the Structure–Property Relationship of Oxygen-Doped Gallium Selenide as an Efficient Photocatalyst for Oxygen Evolution Reaction

• Published in: Journal of physical chemistry. C Vol. 128; no. 25; pp. 10397 - 10406
• Main Authors: Demissie, Ephrem G., Siu, Chi-Kit
• Format: Journal Article
• Language: English
• Published: American Chemical Society 27-06-2024
• Subjects: C: Chemical and Catalytic Reactivity at Interfaces
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.4c02153

A single-layer of GaSe is widely regarded as one of the most promising photocatalysts for a solar-driven water-splitting reaction. However, its catalytic performance is limited by the high onset potential for the oxygen evolution reaction (OER). Achieving the ideal adsorption strength of each intermediate (HO*, O*, and HOO*) involved in the OER process simultaneously via the surface modification of two-dimensional (2D) materials is a significant challenge. In this study, the effects of partial replacement of Se atoms of GaSe with O atoms on the catalytic activity of the resulting 2D GaSe1–x O x surface toward OER have been systematically examined using density functional theory calculations. Our theoretical results revealed that manipulating the atomic configuration of O dopants largely improves the catalytic activity of GaSe1–x O x . When the O-dopants are separated by a −Ga–Se–Ga– unit, the OER is limited by the strong adsorption of the O* intermediate. On the contrary, when a −Ga– unit is bonded with three O-dopants, this O-saturated Ga atom serves as the best site to initiate the OER and exhibits high catalytic performance with a predicted overpotential of 0.38 V, which is comparable with the values of many state-of-the-art precise-metal-based catalysts.