Bromine Ion-Intercalated Layered Bi₂WO₆ as an Efficient Catalyst for Advanced Oxidation Processes in Tetracycline...

The visible-light-driven photocatalytic degradation of pharmaceutical pollutants in aquatic environments is a promising strategy for addressing water pollution problems. This work highlights the use of bromine-ion-doped layered Aurivillius oxide, Bi₂WO₆, to synergistically optimize the morphology and increase the formation of active sites on the photocatalyst's surface. The layered Bi₂WO₆ nanoplates were synthesized by a facile hydrothermal reaction in which bromine (Br^-) ions were introduced by adding cetyltrimethylammonium bromide (CTAB)/tetrabutylammonium bromide (TBAB)/potassium bromide (KBr). The as-synthesized Bi₂WO₆ nanoplates displayed higher photocatalytic tetracycline degradation activity (~83.5%) than the Bi₂WO₆ microspheres (~48.2%), which were obtained without the addition of Br precursors in the reaction medium. The presence of Br^- was verified experimentally, and the newly formed Bi₂WO₆ developed as nanoplates where the adsorbed Br^- ions restricted the multilayer stacking. Considering the significant morphology change, increased specific surface area, and enhanced photocatalytic performance, using a synthesis approach mediated by Br^- ions to design layered photocatalysts is expected to be a promising system for advancing water remediation.