A theoretical and experimental approach for photocatalytic degradation of caffeic acid using BiOBr microspheres

[Display omitted] •BiOBr microspheres were synthesized via solvothermal and varying the bromide source.•Optimal conditions (pH and catalyst dose) were optimized by design of experiments.•Maximum degradation of caffeic acid was achieved at pH 6.7 and 344 mg L−1 of catalyst.•BiOBr synthesized with ionic liquids showed the highest degradation yields. This study describes theoretical and experimental considerations to optimize the photocatalytic degradation of caffeic acid in water using 3D-BiOBr based materials under visible light irradiation. Three BiOBr materials were synthesized through the solvothermal method using different bromide sources, namely potassium bromide (KBr) and the ionic liquid (IL) 1-butyl-3-methylimidazolium bromide. Morphological and chemical changes were observed in IL based 3D-BiOBr materials. The theoretical optimization of the experimental conditions in heterogeneous photocatalysis tests (pH and dose of catalyst) were simulated using the MODDE 12.0.1 software. A central composite design (CCD) was applied to obtain a response surface to elucidate the optimal conditions. This model predicted that the maximum photocatalytic degradation can be achieved at pH of 6.7 and a photocatalyst dose of 344 mg L−1. The optimal experimental conditions were tested using the three synthesized 3D-BiOBr materials. The results showed that the highest degradation efficiency and mineralization yield were obtained using the BiOBr microspheres synthesized with the IL at 145 °C.