Preparation of In2S3 nanosheets decorated KNbO3 nanocubes composite photocatalysts with significantly enhanced activity under visible light irradiation

Abstract

In this work, one kind of novel visible light responsive photocatalysts, In2S3 decorated KNbO3 nanocubes (KNOIS), were successfully synthesized through a facile in-situ growth method. The performance of the obtained nanocomposites was studied by photocatalytic degradation of tetracycline hydrochloride (TC) and Rhodamine B (RhB) under the irradiation of visible light. Results illustrated that the KNOIS nanocomposites had much higher performance than pure In2S3 and KNbO3. The influence of In2S3 amount on the performance of the composites was also studied. Results showed that KNOIS-10 nanocomposite exhibited the best photocatalytic efficiency for TC and RhB degradation. In the degradation of RhB, the apparent rate constant of KNOIS-10 was 0.044 min−1, which was about 22 and 11 times as that of pure KNO (0.0020 min−1) and In2S3 (0.0040 min−1), respectively. The trapping experiments suggested that hydroxyl radicals and holes were two main species for the photocatalytic degradation of RhB by KNOIS. Furthermore, the mechanism on the photocatalytic activity enhancement was proposed relied on the experiments and characterization results. The formed p-n heterojunction enhanced the separation efficiency of photo-induced charges. This work would provide a good example for the preparation of niobate based composite photocatalysts with high photocatalytic activity for environmental remediation.