Effect of silver doping on the properties and photocatalytic performance of In2S3 nanoparticles

The effect of Ag doping on the properties and photocatalytic activity of In2S3 nanoparticles (NPs) was investigated. Pure In2S3 and Ag-doped In2S3 NPs were prepared using a conventional chemical solution process. Different Ag concentrations were used to determine the optimal doping concentration. X-ray diffraction (XRD) results indicated that all the prepared NPs had a polycrystalline cubic crystal structure. In addition, the XRD peaks of the Ag-doped In2S3 NPs showed a slight shift to lower 2θ values than those of the pure In2S3 NPs, indicating the successful incorporation of Ag into the In2S3 lattice. The chemical bonding states and composition of the prepared In2S3 NPs were investigated using X-ray photoelectron spectroscopy. The photocatalytic abilities of the pure and Ag-doped In2S3 NPs under visible-light illumination were evaluated systematically and compared for the decomposition of (i) tetracycline (TC), which is widely used as an antibiotic, and (ii) methylene blue (MB) and rhodamine B (RhB), which are toxic dyes widely used in textile factories. Waste from the production of TC, MB, and RhB has a detrimental impact on the environment and on human health. Overall, the Ag-doped In2S3 NPs exhibited better performance than pure In2S3 NPs for the photocatalytic degradation of TC with higher removal efficiencies. For the Ag: In2S3(2) sample with ∼ 1.4 at.% of Ag, the degradation of TC, MB, and RhB after 3 h was 76.4%, 96.1% and 99.5%, respectively. Furthermore, the Ag-doped In2S3 NPs showed improved hydrogen production via photoelectrochemical water splitting compared to pure In2S3 NPs.