Preparation of g-C3N4/vermiculite composite with improved visible light photocatalytic activity

Abstract Composites of g-C3N4 and vermiculite (gCNV–X, X = 10, 8, 6, 4, 2) with expanded vermiculite (VE) contents of 15.4%, 18.5%, 23.2%, 31.2%, and 47.6% were synthesized by a wet chemical method and provided confined space due to VE. Nanosheets or nanoparticles of g-C3N4 were homogeneously distributed in the gCNV–X composites. With increasing VE content, the photocatalytic activity of gCNV–X improved first, reached the optimum at a VE content of 18.5% (gCNV-8), and then decreased gradually. Composite gCNV-2, with a high VE content of 47.6%, exhibited a similar photocatalytic performance as pure g-C3N4 (gCN). After photocatalysis for 70 min, composite gCNV-8 had degraded 98.07% of RhB with a reaction rate constant that was approximately three times larger than that of gCN. Furthermore, gCNV-8 showed excellent stability and reusability. The composite g-C3N4/vermiculite exhibited an excellent photocatalytic performance, which was ascribed to the reduced particle size of g-C3N4, close interfacial contact, electrostatic interactions between g-C3N4 and vermiculite, enhanced photocarrier separation efficiency, improved photocurrent and light absorption ability, as well as a narrow band gap.