Carbon quantum dot decorated hollow In2S3 microspheres with efficient visible-light-driven photocatalytic activities

Carbon quantum dot (CQDs) decorated hollow In2S3 microspheres were firstly synthesized by a facile hydrothermal method. CQDs with an average size of 5 nm were attached on the surfaces of hollow In2S3 microspheres. The photocatalytic activities of the as-prepared samples were investigated by the photocatalytic degradation of methyl orange under visible light, and the 3 wt% CQDs/In2S3 sample presented the most efficient photocatalytic activity which was almost 3 times the pure In2S3 sample. On the basis of the active species trapping experiment and ESR analysis, holes and superoxide radicals were proved to be the main active species in the photocatalytic degradation process, and a possible reaction mechanism was proposed.