Thermal Oxidation Synthesis of SnSe/SnO2 Heterostructure Nanocomposites with Photocatalytic Activity under Visible Light

Abstract

SnSe/SnO2 nanocomposite was prepared by the thermal oxidation method. These nanocomposites were annealed at 400 °C in an argon atmosphere to improve their crystallinity. The morphology, structure, and performance of the catalyst were characterized by SEM, XRD, TEM, XPS, UV–vis and EIS. The results show that the surface of SnO2 is successfully grown to the surface of SnSe nanocrystals, forming SnSe/SnO2 core–shell heterostructure. The average thickness of SnSe nanoplates is about 30 nm, the average width is about 50 nm and the length is no more than 2 μm. The photocatalytic activity of SnSe/SnO2 nanocomposite was studied. The photocatalytic performance experiment showed that when the photocatalytic reaction time reached 120 min, the degradation rate of methylene blue (MB) by SnSe/SnO2 nanocomposites photocatalyst reached about 50.7%. The mechanism of photocatalytic degradation of MB by the composite may be that with visible light irradiation, photogenerated electrons migrate from the conduction band (CB) of snse to the CB of SnO2, which reacts with oxygen to produce superoxide radical (). MB is degraded due to the strong oxidation of