Effective decolorization of congo red in aqueous solution by adsorption and photocatalysis using novel magnetic alginate/γ-Fe2O3/CdS nanocomposite

Magnetic alginate/gamma-Fe2O3/CdS composite photocatalyst (m-alginate/Fe2O3/CdS composite) was synthesized via a simple hydrothermal method, and characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and vibrating sample magnetometer (VSM). The photocatalytic activity of m-alginate/Fe2O3/CdS composite was evaluated via the adsorption-photocatalytic removal of aqueous organic dye, i.e. congo red (CR). The m-alginate/Fe2O3/CdS composite can be easily manipulated and separated by a magnetic field, leading to the convenience and feasibility in the removal of aqueous hazardous dye. In addition, the kinetics of photocatalysis of CR has also been performed and found to follow the pseudo-first-order kinetics. These results suggest that m-alginate/Fe2O3/CdS composite can be used as an effective photocatalyst for the removal of hazardous pollutants such as dyes, and the adsorption-photocatalysis of these organic contaminants in wastewater effluents can solve one of the most important environmental problems in the related industry. This opens new perspectives for the preparation of magnetic photocatalyst based on biopolymers and effective treatment of aqueous hazardous dye.