A novel V/S co-doped BiOBr catalyst for high-efficiency catalytic reduction of toxic organic and hexavalent chromium pollutants under dark

Organic pollutants in industrial and agricultural wastewater can be dangerous to both human health and the environment. Therefore, it is important to develop methods for continuous catalytic reduction of these pollutants under dark conditions as sunlight has geographical and temporal limitations due to different regions, weather conditions, and Earth's rotation. This could have significant implications for practical wastewater treatment. In this study, we successfully synthesized bimetallic vanadium bismuth oxy-sulfo bromide (labeled as VBiOSBr) catalysts using a simple precipitation method by doping V/S into BiOBr to from (Bi,V)(S,O)Br. The morphology, structure, optical absorption properties, electron-hole recombination rate, and reduction performance of the catalysts were examined in detail. The catalyst displayed a tetragonal phase with an energy band gap and specific surface area of approximately 1.93 eV and 22.1 m2/g, respectively. The 1-VBiOSBr catalyst prepared with n(V): n(Bi): n(KBr): n(C2H5NS) = 1: 1: 1: 1 had the best catalytic activity. Within just 14 min, this catalyst removed 98.7% and 96.96% of 4-NP and Cr6+, respectively. The VBiOSBr catalyst remained stable and efficient even after the seventh run, still achieving a removal rate of 94.7%. The study proposed a possible mechanism for 4-NP and Cr6+ reduction activity. The catalyst's simple manufacturing process and its ability to reduce pollutants under dark conditions make it a promising system for practical application in the continuous removal of organic pollutants. So, the VBiOSBr bimetallic catalyst has great potential as a candidate for wastewater treatment technologies.