In situ anion exchange synthesis of In2S3/In(OH)3 heterostructures for efficient photocatalytic degradation of MO under solar light
Fabrication of heterostructure photocatalysts to improve photocatalytic performance is always a hot topic in the photocatalytic field. In this paper, In2S3/In(OH)3 heterostructure photocatalysts were synthesized via a simple combination of an in situ anion exchange reaction and the hydrothermal process. The obtained heterostructures were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectra (UV-vis DRS) and photocurrent experiment. The photocatalytic activity of the as-formed samples was evaluated by the degradation of methyl orange (MO), salicylic acid and 4-chlorophenol aqueous solution under simulated solar light irradiation (200 nm < λ < 800 nm). The results showed that the photocatalytic activities of In2S3/In(OH)3 heterostructures were greatly improved as compared to single phase In(OH)3 and In2S3. The enhancement in their photocatalytic activity could be attributed to the efficient charge transfer in In2S3/In(OH)3 heterostructures, the improved light absorbance capacity and the increased surface area. As compared, In2S3/In(OH)3 displayed higher photocatalytic activity than In2S3/In2O3 at the same In2S3 content. The excellent activity of In2S3/In(OH)3 with respect to In2S3/In2O3 was mainly due to the high concentrations of ˙O2− radicals and the strong oxidation capacity (h+). The current research provides a new insight into the construction of a narrow-band-gap with a wide-band-gap to form heterostructures as promising and efficient photocatalysts for the removal of harmful organic compounds in aqueous solution.