Investigation of the efficiency of BiOI/BiOCl composite photocatalysts using UV, cool and warm white LED light sources - Photon efficiency, toxicity, reusability, matrix effect, and energy consumption

BiOI, BiOCl, and their composites (BiOI:BiOCl) with molar ratios from 95:5 to 5:95 were synthesized tested in the transformation of methyl orange (MO) sulfamethoxypyridazine (SMP) antibiotic, using three various LED light sources: UV LEDs (398 nm), cool warm white (400–700 nm). The 80:20 BiOI:BiOCl photocatalyst showed best adsorption capacity for MO enhanced activity compared BiOI BiOCl. apparent quantum yield (?app) SMP was slightly lower than 398 nm radiation. effect methanol 1,4-benzoquinone proved that is initiated mainly via direct charge transfer, resulting demethylation SO2 extrusion SMP. change photocatalytic efficiency followed during cycles. After first one, rates decreased, but there no significant difference between second third decreased most probably caused by intermediates, whose continuous accumulation observed Ecotoxicity measurements confirmed toxic substances leached catalyst, both results intermediates. Using source, energy requirement removal about half value determined TiO2 a mercury vapor lamp. some components wastewater (Cl?, HCO3? humic acids), pH, two matrices on composite photocatalysts' stability also investigated.