Photocatalytic degradation and photocatalytic hydrogen production of rambutan-like structure In₂S₃/CaIn₂S₄ composites

In2S3/ CaIn2S4 composites were synthesized by a programmed temperature hydrothermal method. The crystal structure, morphology, and surface physicochemical properties of In2S3/ CaIn2S4 composites were tested by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, UV-Visible diffuse reflectance spectroscopy, and N-2 adsorption-desorption measurements. The results show that In2S3/ CaIn2S4 composite contains mixed phases of tetragonal phase CaIn2S4 and cubic phase In2S3, and has the rambutan-like structure with a favor optical absorption in visible region. Using methyl orange as the degradation object, the photocatalytic degradation experiments were carried out under ultraviolet light, visible light, and simulated sunlight. The results show that In2S3/ CaIn2S4 composite with the molar ratio of 1:10 possesses the best photocatalyst activity. Meanwhile, the composite presents the certain extensiveness in the degradation of organic pollutants with different structures, it also has a certain photocatalytic hydrogen ability, and its photocatalytic hydrogen production activity is much higher than that of commercially available P25. In addition, based on the trapping experiments, a possible photocatalytic mechanism of In2S3/ CaIn2S4 was proposed.