Promising two dimensional XSe2/SnS (X= Pt, Zr, Hf) vdW heterostructures for overall water splitting with higher carrier mobilities

Abstract

The transition metal dichalcogenides (TMDs) are considered as promising candidates for their striking performance in optoelectronic properties. We have designed the novel heterostructures XSe2/SnS using XSe2 (X = Pt, Zr, Hf) TMDs. The stabilities of structural, mechanical, dynamical, and thermal are calculated by formation energies, elastic constants, phonon dispersions and AIMD simulations respectively. The hybrid functional (HSE06) is used to calculate the electronic band structures and optical absorption. The DFT scheme (BGC based) indicates that XSe2/SnS vdWHs are viable photocatalyst for overall water splitting over a broad spectrum of light. The absorption spectra exhibit that these photocatalysts have absorption started from visible to the UV region of light in the order of 105. XSe2/SnS heterostructures display high carrier mobilities of order 104. The Gibbs free energies exhibit that PtSe2/SnS heterostructure has spontaneous, whereas other heterostructures need some external energies for overall water splitting. Finally, the corrected STH efficiency of PtSe2/SnS, ZrSe2/SnS and HfSe2/SnS vdW heterostructures are 12.54%, 28.15%, 21.03% respectively. This study depicts that XSe2/SnS (X = Pt, Zr, Hf) heterostructures are feasible candidates for overall water splitting over a broad range of light spectrum.