Hydrogen production from photocatalytic water splitting in the InP/SnS2 heterojunction: First-principles calculations

In the present era, the environmental issues and resource shortages caused by energy development have become increasingly severe. To address this problem, the method of preparing hydrogen through photocatalytic water splitting technology has been proposed and has developed rapidly. This study investigates InP/SnS₂ heterojunctions for photocatalytic water splitting using first-principles calculations. The heterojunction has a 1.33 eV bandgap with a Type-II alignment, facilitating effective electron-hole separation. Work function analysis shows electrons transfer from InP to SnS₂, with a total Bader charge transfer of 0.10 $\left(e\right)$. The charge transfer follows a Z-scheme pathway, enhancing photocatalytic activity. The heterojunction meets redox requirements, exhibits an absorption peak at 2.07 × 10⁵ cm⁻¹ within the visible spectrum, and achieves a solar-to‑hydrogen efficiency of 9.83 %. These properties suggest that InP/SnS₂ heterojunctions are promising for future photocatalytic applications.