Thorny hydrangea-like SnIn4S8/Mn0.3Cd0.7S as novel type-II heterojunction photocatalyst to enhance the efficient degradation of imidacloprid

The construction of type-II heterojunction structure is considered to be an effective method to enhance the separation of electron-hole pairs in photocatalysts. A series of SnIn4S8/Mn0.3Cd0.7S (SIS/MCS) heterostructure photocatalysts were prepared by an in-situ growth method. The synthesized photocatalysts were tested and analyzed via various testing techniques, and their photodegradation efficiencies of imidacloprid were evaluated. Compared with the pure SIS, the SIS/MCS-10 showed increased photocatalytic degradation performance by a nearly 4.3-fold and 10.9-fold compared with pure SIS and MCS, respectively, mainly because the formation of type-II junction, inhibiting the recombination of electron-hole pairs and effectively improving the photocatalytic degradation rate. The excellent stability of the SIS/MCS-10 composite was proved by four-run cycle experiments. Moreover, the influences of interfering anions and water matrices on the photoactivity of the SIS/MCS were studied. This work provides useful guidance on the design and preparation of type-II heterojunction photocatalysts for imidacloprid degradation.