Green synthesis of α-Fe₂O₃/BiPO₄ composite and its biopolymeric beads for enhanced photocatalytic application

This study reports a green and facile hydrothermal method to synthesis α-Fe₂O₃/BiPO₄ composite and was used for photocatalytic application under visible light irradiation. The synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis diffuse reflectance spectrum (UV–Vis DRS), Fourier transform infrared (FT-IR) spectrum, X-ray photoelectron spectroscopy (XPS), Brunauer–Emmet–Teller (BET) analysis and Photoluminescence (PL), which confirmed the formation of the composite. XRD analysis indicated that all the prepared samples present in pure hexagonal structure without Fe₂O₃ phases. The photocatalytic studies on methylene blue (MB) and ciprofloxacin (CIP) were evaluated under visible light irradiation and the α-Fe₂O₃/BiPO₄ composite exhibited superior photocatalytic activity compared to the BiPO₄. The results of PL studies substantiated that the enhancement of photocatalytic activity could be mainly attributed to the interaction of α-Fe₂O₃ and BiPO₄ in the composite during photocatalysis which effectively improve electron–hole separation. The recyclability experiment corroborated the stability of α-Fe₂O₃/BiPO₄ composite. Finally, the composite was converted into beads using calcium alginate, a non toxic biopolymer for easy separation of the catalyst from the reaction medium, which also showed equally good results.