BiOCl/BiOI composit photocatalysts - investigation of their efficiency using UV and visible led light sources

Due to its unique layered structure, bismuth oxyhalide (BiOX, where X=F, Cl, Br, I) has potential applications as a photocatalytic material in clean energy utilization and environmental purification. In this work, BiOI, BiOCl, and their composites with various BiOI:BiOCl molar ratios were synthesized and characterized for their heterogeneous photocatalytic applications. The methyl orange was used as a model pollutant and UV and visible LED light sources were applied. Adsorption measurements and photocatalytic tests proved that, the BiOI/BiOCl composite, which contains 80% BiOI and 20% BiOCl, showed the best activity. The composite catalyst showed good activity under visible light and was particularly better than pure BiOI and BiOCl under UV radiation. The transformation mechanism of methyl orange is initiated by direct charge transfer processes, via photosensitization