Synthesis of CaIn2S4/TiO2 heterostructures for enhanced UV–visible light photocatalytic activity

Semiconductor heterostructures are regarded as an efficient way to improve the photocatalytic activity. Herein, novel Z-scheme CaIn2S4 (CIS)/TiO2 heterostructures photocatalysts were synthesized by a simple two-step hydrothermal approach. Compared with single phase nanostructures of TiO2 and CIS, the CIS/TiO2-0.05 g nanocomposites exhibited efficient and stable photocatalytic activity, with 97% of methyl orange (MO) decomposed within 30 min under UV–visible light irradiation. In addition to increased broad light absorption, the outstanding photocatalytic performance is mainly attributed to intimate contact and matched energy band positions between CIS and TiO2, which efficiently produce more active electrons and holes, reduce the photogenerated electron-hole recombination, and boost photoinduced charge carrier transfer. The possible Z-scheme mechanism for the photocatalytic reaction in the system was reasonably proposed. This work would arouse an increasing interest in designing more Z-scheme heterojunction photocatalysts with high efficiency for the application of photodegradation.