中文摘要：

采用第一性原理方法研究了层间耦合作用对g-C3N4／SnS2异质结构的电子结构和吸光性质的影响．发现g-C3N4／SnS2是一类典型的范德瓦异质结构，能有效吸收可见光，其价带顶和导带底与水的氧化还原势匹配，且由于电荷转移而导致的界面处极化场有利于光生载流子的分离．这些理论研宄结果表明g-C3N4／SnS2异质结构是一类非常有潜力的光解水催化材料．

英文摘要：

Graphite-like carbon nitride （g-C3N4） based heterostrutures has attracted intensive attention due to their prominent photocatalytic performance. Here, we explore the g-CaN4/SnS2 coupling effect on the electronic structures and optical absorption of the proposed g-CaN4/SnS2 heterostructure through performing extensive hybrid functional calculations. The obtained geometric structure, band structures, band edge positions and optical absorptions clearly reveal that the g-C3N4 monolayer weakly couples to SnS2 sheet, and forms a typical van der Waals heterojunction. The g-C3N4/SnS2 heterostructure can effectively harvest visible light, and its valence band maximum and conduction band minimum locate in energetically favorable positions for both water oxidation and reduction reactions. Remarkably, the charge transfer from the g-C3N4 monolayer to SnS2 sheet leads to the built-in interface polarized electric field, which is desirable for the photogenerated carrier separation. The built-in interface polarized electric field as well as the nice band edge alignment implys that the g-CaN4/SnS2 heterostructure is a promising g-CaN4 based water splitting photocatalyst with good performance.