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

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.