Visible light induced photocatalytic degradation of rhodamine B by magnetic bentonite

The photocatalytic activity of magnetic bentonite, Fe₃O₄ nanoparticles decorated Al-pillared bentonite (Fe₃O₄/Al-B), for the degradation of rhodamine B (RhB) in the presence of H₂O₂ under visible light (VL) was evaluated. The effects of different reaction parameters such as catalyst dose, dye concentration and externally added H₂O₂ were also investigated. The magnetic bentonite showed good photocatalytic activity, magnetic separability and stability for repeated use. More than 95% of 40 mg/L RhB was converted within 3 h under VL with a catalyst dose of 0.5 g/L. Suitable mechanisms have been proposed to account for the photocatalytic activities in the presence and absence of H₂O₂. The efficiency of H₂O₂ in VL process was much higher than that of the dark process. Results obtained in the current study may be useful to develop a suitable photocatalyst for photocatalytic remediation of different water contaminants including organic dyes.