Key points are not available for this paper at this time.
We present a theoretical investigation of van der Waals heterostructures composed of out-of-plane doped X@g-C₃N₄ monolayers (X = S, 0. 1em{0ex}Se) coupled with WTe₂, TcTe₂, AlP₃, or InP₃ for efficient overall water splitting via a direct Z-scheme mechanism. First-principles calculations reveal that WTe₂/X@g-C₃N₄ and TcTe₂/X@g-C₃N₄ exhibit high solar-to-hydrogen (STH) efficiencies, reaching up to 25. 88%. However, thermodynamic analysis indicates that both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) remain energetically unfavorable. In contrast, AlP₃/X@g-C₃N₄ and InP₃/X@g-C₃N₄ heterostructures demonstrate more balanced photocatalytic behavior, achieving STH efficiencies of up to 31. 95%, while the HER can be driven spontaneously. Moreover, cocatalysts are necessary for driving the OER, needing external energies of 0. 94 and 1. 79 eV for InP₃/X@g-C₃N₄ heterostructures. Furthermore, nonadiabatic molecular dynamics simulations reveal rapid interfacial electron-hole recombination in the TcTe₂/X@g-C₃N₄ heterostructure, suggesting enhanced charge separation and transport pathways in the Z-scheme configuration. This study highlights the potential of heterostructure engineering combined with out-of-plane doping as a versatile strategy to optimize g-C₃N₄-based photocatalysts, and identifies InP₃/X@g-C₃N₄ as promising candidates for high-efficiency solar-driven water splitting.
Shi et al. (Mon,) studied this question.