Two-dimensional Pd3(AsSe4)2 as a photocatalyst for the solar-driven oxygen evolution reaction: a first-principles study

The relationship between the structure and properties of materials is the core of material research. Bulk Pd3(PS4)2 materials have been successfully synthesized in the field of three-dimensional materials. After that, various studies on two-dimensional layered materials were conducted. Inspired by these successes, this work used density functional theory based on first principles to explore similar two-dimensional Pd3(AsX4)2, where X is S, Se, or Te belonging to the same group. Our findings demonstrate that the Pd3(AsS4)2 and Pd3(AsSe4)2 monolayers, with HSE06 band gaps of 2.37 and 1.36 eV, respectively, are indirect semiconductors. Additionally, their carrier mobilities [523.23 cm2 s-1 V-1 and 440.6 cm2 s-1 V-1] are also proved to be superior to MoS2 [∼200 cm2 s-1 V-1]. The optical calculations indicate that the Pd3(AsSe4)2 monolayer yields suitable valence band edge positions for the visible-light-driven water splitting reactions. More interestingly, at a low applied voltage of 0.14 V, Pd3(AsSe4)2 exhibits outstanding oxygen evolution reaction performance. In this study, the possible mechanism for the ability of Pd3(AsSe4)2 monolayer to promote photocatalysis and oxygen evolution was explained, which may pave the way for the practical design of further solar-driven high-quality water splitting photocatalysis.