Photocatalytic removal of crystal violet by C–MIL–53(Fe)@BiOI heterojunction: Process modeling and optimization

Abstract

A facile synthesize protocol was utilized to prepare C–MIL–53(Fe)@BiOI photocatalyst with exceptional performance under 5-watt visible light irradiation. The prepared material was characterized for physio-chemical and optical properties. The EDX and N2 adsorption–desorption analysis revealed the heterojunction surface contained ∼ 71.48 % bismuth by weight, and a BET surface area of 12.96 m2/g. Box-Behnken design (BBD) was applied for the experimental study to optimize the process of crystal violet (CV) removal by low-powered LED irradiation. BBD also provided essential information on the effect of independent parameters i.e., pH, photocatalyst dose, CV concentration, reaction time, their interactions, and dye removal prediction under determined operating conditions. Screening tests indicated a significant improvement in catalytic performance for C–MIL–53(Fe)@BiOI composite compared to parent materials, MIL–53(Fe), and C–MIL–53(Fe). Maximum removal of 96.8 % was achieved for CV degradation at pH = 4, photocatalyst dosage = 0.55 g/L, CV concentration = 10 mg/L, and irradiation time = 38 min. Mechanistic study nominated OH. radicals as the most active species participate in CV degradation. C–MIL–53(Fe)@BiOI represents a viable material owing to the promising removal performance against cationic dye under low-energy irradiation.