Fabrication of carbon quantum dots/TiO2/Fe2O3 composites and enhancement of photocatalytic activity under visible light

Carbon quantum dots/TiO 2 /Fe 2 O 3 photocatalytic composite was prepared through multi-step hydrothermal method. The CQDs/TiO 2 /Fe 2 O 3 composite showed enhanced photocatalytic performance for methylene blue dye photodegration when compared with TiO 2 /Fe 2 O 3 and pure TiO 2 under the visible light irradiation. The mechanism of the improved photocatalytic activity over CQDs/TiO 2 /Fe 2 O 3 were also investigated. The CQDs can better capture and transfer photogenerated electrons through the Ti-O-C and Fe-O-C bonds. What's more, CQDs can improve the utilization of photogenerated electrons and the electrons in CQDs are captured by O 2 to produce •O 2 - radicals and the role of •O 2 - radicals in the photocatalytic process is significantly improved.