Two-dimensional (2D) van der Waals (vdW) materials have been widely adopted as photocatalysts in water splitting. Based on the first-principles calculations within screened hybrid functional of Heyd-Scuseria-Ernzerhof (HSE), we find that Janus group-III chalcogenide based vdW heterojunction (SeGa₂Te/SeIn₂Se) is a promising visible-light-driven photocatalyst regardless on the stacking configuration. The SeGa₂Te/SeIn₂Se in AA stacking satisfy the requirement for the band gap under both pH = 0 and pH = 7 according to standard water-splitting mechanism. The notable intrinsic electric field (v-EF) in the AB stacking of SeGa₂Te/SeIn₂Se alter the band alignment and enhance the overpotentials of the photogenerated carriers to efficiently drive the redox reaction. In both stacking, the type-II band alignment, suitable direct band gaps, high optical absorbance and high power conversion efficiency promote the photocatalytic efficiency. Furthermore, outstanding photocatalytic ability and efficiency are maintained under both vertical and in-plane strains, guaranteeing the application under natural environment.

二维 (2D) 范德华 (vdW) 材料已被广泛用作水分解中的光催化剂。基于筛选出的 Heyd-Scuseria-Ernzerhof (HSE) 杂化功能中的第一性原理计算，我们发现基于 Janus III 族硫属化物的 vdW 异质结 (SeGa ₂ Te/SeIn ₂ Se) 是一种很有前途的可见光驱动光催化剂无论堆叠配置如何。根据标准的水分解机制，AA堆叠中的SeGa ₂ Te/SeIn ₂ Se满足pH = 0和pH = 7下的带隙要求。SeGa ₂ Te/SeIn ₂ AB 堆叠中显着的本征电场 (v-EF)Se 改变能带排列并增强光生载流子的过电位，以有效地驱动氧化还原反应。在两种堆叠中，II型能带排列、合适的直接带隙、高吸光度和高功率转换效率促进了光催化效率。此外，在垂直和面内应变下均保持出色的光催化能力和效率，保证了在自然环境下的应用。