Exploration of two-dimensional XPY3 (X = Zn, Cd; Y[dbnd]S, 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, ZnPS 3 , ZnPSe 3 , CdPS 3 and CdPSe 3 , 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 H 2 and O 2 , and show acceptable free energy for hydrogen evolution reaction (HER) of 0.89–1.20 eV. Moreover, monolayer ZnPSe 3 and CdPSe 3 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. • 2D ZnPS 3 , ZnPSe 3 , CdPS 3 and CdZnSe 3 have high stability, as well as low cleavage energies of 0.21–0.25 J/m2. • They are indirect semiconductors with band-gaps of 2.24–3.29 eV, and show mobilities of 192.26–676.04 cm2/Vs at 300 K. • They also have suitable REDOX band-edges, which can drive photocatalytic water splitting to produce H 2 and O 2. • Monolayer ZnPSe 3 and CdPSe 3 have excellent solar-to-hydrogen efficiency of 18.39% and 19.70%. [ABSTRACT FROM AUTHOR]