Synthesis of sodium dodecyl sulfate modified BiOBr/magnetic bentonite photocatalyst with Three-dimensional parterre like structure for the enhanced photodegradation of tetracycline and ciprofloxacin

Antibiotic contamination poses serious ecological and human health threats. To control these impacts, an economical and novel three-dimensional (3D) heterogeneous sodium dodecyl sulfate (SDS) modified BiOBr/magnetic bentonite (SDS/BiOBr-MB) with enhanced photocatalytic activity against tetracycline (TC) and ciprofloxacin (CIP) was fabricated via constructing flower-like BiOBr blossomed in the layered MB via a facile and mild approach. Compared with bare BiOBr, BiOBr-MB and SDS/BiOBr-MB catalyst owing to the introduction of magnetic Fe3O4/bentonite (MB) and parterre like structure, exhibited enhanced photocatalytic degradation activity of TC (85%) and CIP (95%). pH 6–8 favored higher photodegradation of TC and CIP using SDS/BiOBr-MB as compared to acidic or alkaline conditions. SDS/BiOBr-MB remained highly stabile and active for five consecutive reuses. The enhanced photocatalytic performance of SDS/BiOBr-MB was attributed to the presence of SDS, the n-n heterojunction between BiOBr and Fe3O4, and the introduction of bentonite which constructed a platform dispersing the growth of BiOBr. Through the function of SDS, BiOBr with the micro-flower shape having good adsorption ability and dispersing effect was self-assembled from nano-sheet-shaped BiOBr under hydrothermal conditions. The n-n heterojunction between BiOBr and Fe3O4 enhanced the separation and transfer efficiency of photo-generated electron-hole pairs of SDS/BiOBr-MB. The permanent negative charge on the surface of bentonite exhibited the ability to capture photo-generated holes and thus reduced the combination of photo-generated carriers. This study could provide valuable reference for the fabrication of new ternary visible-light responsive catalysts for the photodegradation of antibiotics and other organic pollutants.