Exploration of two-dimensional XPY3 (X = Zn, Cd; YS, Se) for photocatalytic water splitting

Two-dimensional (2D) materials are attracting much attention as emerging photocatalytic water splitting candidates in green and clean energy applications. In this work, we designed four 2D materials, ZnPS3, ZnPSe3, CdPS3 and CdPSe3, which possess high stability, moderate band-gaps (2.24–3.29 eV), and anisotropic carrier mobilities of 192.26 ─ 676.04 cm2/Vs. Besides, they also have suitable band edges of REDOX at PH = 0, which can simultaneously drive photocatalytic water splitting to produce H2 and O2, and show acceptable free energy for hydrogen evolution reaction (HER) of 0.89–1.20 eV. Moreover, monolayer ZnPSe3 and CdPSe3 can deliver strong absorption coefficients (∼105 cm−1) from visible to ultraviolet light. As a result, they have excellent solar-to-hydrogen efficiency of 18.39% and 19.70%, suggesting they are promising photocatalytic candidates for overall water splitting.