Effective photocatalytic degradation of rhodamine B by a novel bentonite-Ag₃PO₄ composite: operational parameters and mechanistic considerations

In this study, Bentonite-Ag₃PO₄ (BAP) material was synthesized via the co-precipitation method, and its photocatalytic activity was evaluated for the degradation of Rhodamine B (RhB) at a concentration of 10 mg/L in a 300 mL solution under simulated UV irradiation. The synthesized material was characterized using various techniques, including X-ray diffraction, Fourier-transform infrared spectrometry, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM–EDS), UV–Vis diffuse reflectance spectroscopy (DRS), and Brunauer–Emmett–Teller (BET) surface area analysis. The photocatalytic activity of BAP at a concentration of 1 g/L exhibited excellent performance, achieving 100% degradation of RhB after 90 minu under simulated UV_{365 nm} irradiation. The charge carrier pathway was investigated using scavengers for photogenerated holes (h⁺), hydroxyl radicals (HO^⋅), and superoxide radicals ( \({\text{O}}_{2}^{\cdot -}\) ${\text{O}}_2^{·-}$ ), such as ethylenediaminetetraacetic acid (EDTA), isopropanol (IPA), and benzoquinone (BQ).