In this study, a novel TiO2-CuS heterojunction nanocomposite was prepared from TiO2 anatase nanoparticles and CuS nanoflakes through hydrothermal method and used, for the first time, as a visible-light photocatalyst for decomposition of agricultural insecticide Nitenpyram. Crystallinity, shape, and size of particles, and optical properties of the prepared nanocomposite were investigated using FESEM, XRD, Mott-Schottky, photoluminescence (PL), and UV-Visible spectroscopy analyses. The results indicated that the TiO2-CuS heterojunction nanocomposite was successfully prepared and compared to the pure CuS and TiO2 semiconductors, it exhibited a better photocatalytic performance mainly due to the improvement in optical properties (increasing the ability of visible-light absorbance) and reduction of the photoinduced electron and hole recombination rate. According to the Mott-Schottky analysis and radical scavenger tests, superoxide radical was detected as the major oxidizing agent involved in photocatalytic degradation of Nitenpyram, and a type II charge transfer pathway was suggested to improve the photocatalytic activity.
