Electronic structure, optical, and photocatalytic properties of SnS, SnSe and their van der Waals heterostructures are investigated by first-principle calculations. Thermal stability confirmed that SnS, SnSe and SnS-SnSe van der Waals heterostructure are thermodynamically stable. The calculated band structure shows that SnS, SnSe and SnS-SnSe van der Waals heterostructure are indirect band nature while the heterostructure are confirmed for type-II band alignment. Bader charge analysis shows that the charges are transfer from SnS layer to SnSe layer. Furthermore, absorption spectra are calculated to understand the optical behavior of these systems, where the lowest energy transitions are lies in visible region. The valence and conduction band edges straddle the standard redox potentials in SnS, SnSe and their van der Waals heterostructures van der Waals heterostructures, making them promising candidates for water splitting in the acidic solution.

通过第一性原理计算研究了SnS，SnSe及其范德华结构的电子结构，光学和光催化性能。热稳定性证实SnS，SnSe和SnS-SnSe van der Waals异质结构是热力学稳定的。计算的能带结构表明，SnS，SnSe和SnS-SnSe范德华异质结构是间接能带性质，而该异质结构可用于II型能带排列。不良电荷分析表明，电荷从SnS层转移到SnSe层。此外，计算吸收光谱以了解这些系统的光学行为，其中最低的能量跃迁位于可见光区域。价带和导带边缘跨越SnS中的标准氧化还原电势，