Enhanced photocatalytic activity of MoS2 via N + F codoping and strain engineering: A first-principles investigation

Abstract

The inert basal plane severely limited the catalytic activity of MoS2 monolayer. Therefore, activating the catalytic inert basal plane is a great challenge. Here, two strategies, N + F codoping and strain engineering, are proposed to improve the photocatalytic activity of MoS2 monolayer utilizing the first-principles calculation. The Gibbs free energy change (ΔGH = -0.081 eV) for the hydrogen evolution reaction (HER) of N + F codoped MoS2 monolayer indicates the distinctly enhanced HER activity compared with pristine MoS2 monolayer (ΔGH = 2.087 eV). The LUMO and HOMO reveal that MoS2 monolayer with N + F codoping possesses the more catalytic active sites. Additionally, the ratio of the effective mass (2.32) in N + F codoped MoS2 predicts a higher photoexcited carriers separation efficiency than in MoS2 (1.18). The N + F codoped MoS2 owns decent band-edge positions with the compressive strain of 2 %, demonstrating the enhanced photocatalytic properties. This work theoretically proposes N + F codoping and applying strain MoS2 monolayer exhibits promising application potential in the field of photocatalytic overall water splitting. These results expect to provide guidance and reference for the experimental elevating the highly active photocatalytic performance of MoS2 monolayer from the theoretical aspect.