Sandwich-like SnO2/MoO3−x prepared by electrostatic self-assembly for high-performance photocatalysis

Sandwich-structured SnO2/MoO3−x has been successfully synthesized through electrostatic self-assembly. The crystal structure, morphology, size and composition of products were investigated by XRD, TEM (HRTEM), XPS and UV–Vis technologies. It was found that SnO2 nanoparticles are embedded between the layers of MoO3−x nanosheets. The investigation of photocatalytic properties indicated that the SnO2/MoO3−x heterostructure possessed excellent photocatalytic ability superior to SnO2 and MoO3 for the degradation of Rhodamine B and methylene blue driven by visible light. The results indicated that SnO2/MoO3−x acts as the trapping centers of photo-induced electrons and holes, which can promote the separation of photo-induced electron–hole pairs and charge migration. Furthermore, the photocatalyst SnO2/MoO3−x showed excellent recoverability as its photocatalytic activity remained even after five cycles.