Investigation the Synergistic Effect of Adsorption and Photocatalysis for Removal of Dye Pollutants by Hydrogel Supported In2S3 Nanoparticles

Homogenous catalysis which the catalyst operates in the same phase as the reactants is definitely efficient in catalysis processes while it suffers from the impossibility or inconvenience of the catalyst removal from the reaction media. In this research, In2S3 nanoparticles were synthesized by a simple precipitation method and later on immobilized and stabilized in the porous structure as a substrate. The properties of pure hydrogel and In2S3 in hydrogel were characterized by FTIR, DRS, XRD, BET, BJH, FESEM, and EDX. The DRS results confirmed that the stabilization of nanoparticles in hydrogel led to a redshift of the bandgap. The hydrogel with In2S3 indicated a more porous structure in comparison with pure hydrogel. Due to the decrease of bandgap and the increase of specific surface area, In2S3 nanoparticles stabilized in hydrogel removed Rhodamine B (RhB) as a model pollutant very well. The performance of the catalyst in the removal of RhB under dark conditions (adsorption) and visible light irradiation (photocatalysis) was investigated and 77.7% and 95.2% of dye removal percentages were obtained in 120 min under dark and light irradiation, respectively. In conclusion, immobilization In2S3 as a high-efficiency visible light photocatalyst in hydrogel provided a promising heterogeneous and reusable catalyst for water treatment.