Type-II p(SnSe)-n(g-C3N4) heterostructure as a fast visible-light photocatalytic material: Boosted by an efficient interfacial charge transfer of p-n heterojunction

Abstract

Pristine single-crystalline SnSe nanoparticle (NPs) and SnSe/g-C3N4 nanocomposites with a high efficient visible-light photocatalytic performance were synthesized by a co-precipitation method in an ambient condition. X-ray diffraction (XRD) patterns indicated an orthorhombic phase for all samples. In addition, the XRD patterns and transmission electron microscopy (TEM) images showed crystallite and particle sizes of the SnSe NPs were decreased by g-C3N4. Mott-Schottky (MS) results of the products indicate a p-type semiconductor behavior for the pristine SnSe NPs, while, it was observed an n-type semiconductor behavior for the SnSe/g-C3N4 nanocomposites. A synergetic effect on the photocatalytic performance of SnSe NPs was observed by g-C3N4. However, there was an optimum concentration of g-C3N4 (10%) to enhance the photocatalytic performance of the SnSe NPs. The electrical measurement results indicated that p-n heterojunction led to promote efficient interfacial charge transfer between two parts of heterostructure and resulting in increased electron-hole pairs (EHP) lifetime.