BiOBr/ZnWO4 heterostructures: An important key player for enhanced photocatalytic degradation of rhodamine B dye and antibiotic ciprofloxacin

Abstract

We report a facile synthesis of p-BiOBr/n-ZnWO4 heterostructures by hydrothermal/precipitation method as an important key player to enhance the photocatalytic degradation of Rhodamine B (RhB) dye and ciprofloxacin antibiotic. The structural and microstructural features confirm that p-BiOBr/n-ZnWO4 heterostructures display a mixed tetragonal/monoclinic phase with the presence of several n-ZnWO4 nanocrystals on the surface of petals of flower-like p-BiOBr microcrystals. X-ray photoluminescence (XPS) analysis of BiOBr exhibits the existence of Bi, O, and Br, whereas BiOBr/ZnWO4-5%, in addition to Bi, O, and Br, consist of signature of Zn and W. UV�Visible spectra of p-BiOBr/n-ZnWO4-5% showed better absorption than p-BiOBr and n-ZnWO4, which displayed an enhanced collection of photons in the heterojunction. An intense photoluminescence emission at room temperature was observed for p-BiOBr microcrystals as compared to p-BiOBr/n-ZnWO4. We observed the best photocatalytic activity for p-BiOBr/n-ZnWO4-2.5% in the degradation of RhB dye at 99.4% in 25 min and CIP antibiotic at 58.2% in 170 min, which is assigned due to high surface area SBET (13 m2/g), pore size, providing active catalytic sites for bonding chemical and surface interaction and bonding chemical between the bromide/oxides. Finally, we have investigated the use of scavengers for isopropanol, benzoquinone, and sodium azide, which proves that the hydroxyl (�OH) and superoxide (O2?) radicals as the foremost reactive oxygen spicies (ROS) in photocatalytic degradation of RhB dye and antibiotic CIP. � 2022 Elsevier Ltd