Insight into electronic structure and photocatalytic character of GaSe/MoS2 heterostructure by first-principles investigation.

The electronic structure and photocatalytic properties of two-dimensional GaSe/MoS 2 heterostructure are systematically studied by first-principles calculation. It is found that it could be used as a potential visible light catalyst to decompose water into H 2 and O 2. The lattice mismatch rate is 3.55%, and the binding energy was −0.446 eV, indicating that it has a stable configuration. An indirect band gap of 2.255 eV with hybrid HSE06 functional is observed, which falls into a wide range of visible light absorption. It exhibits II-type band alignment and this can promote the spatial separation of photogenerated carriers. In addition, the band edge spans the redox potential of water, indicating that heterostructure can produce hydrogen by photocatalytic decomposition H 2 O. The electrons transfer from GaSe to MoS 2 layer, while the holes do the opposite, thus improving the photocatalytic efficiency. Therefore, GaSe/MoS 2 heterostructure has broad application prospects in photocatalysis. • The GaSe/MoS 2 heterostructure is a very promising photocatalyst. • Work function of a material plays a momentous role in the band alignments. • The density of state can show the mechanism behind the orbital reconfiguration. • Semiconductor photocatalysis is considered as an ideal way to convert solar energy into chemical energy. [ABSTRACT FROM AUTHOR]