Efficient adsorption and photocatalytic degradation of Rhodamine B dye over Bi2O3-bentonite nanocomposites: A kinetic study

•Bi2O3-bentonite nanocomposites synthesized by intercalation method.•Bi2O3-bentonite effectively catalyses the photodegradation of Rh B.•Bi2O3-bentonite is a potentially suitable catalyst for photodegradation of Rh B under visible light irradiation.•Photodegradation of Rh B by Bi2O3-bentonite generates less/non toxic products. Bi2O3-bentonite nanocomposites successfully synthesized by intercalation method, are used for photocatalytic degradation of Rhodamine B (Rh B) under visible light irradiation. Bi2O3-bentonite shows enhanced photocatalytic efficiency than pure Bi2O3 due to intercalation with bentonite. Removal of Rh B is achieved upto 98.5% using 3 gL−1 photocatalyst at pH 3. It is found that increase in light absorption and decrease in electron-hole recombination enhances photocatalytic efficiency. Photocatalytic degradation of Rh B by Bi2O3-bentonite proceeds via advanced oxidative process. The plausible mechanism of photocatalytic degradation Rh B reported by LC-MS shows generation of different degradation products including benzoic acid and benzonium ion.