Mesoporous Silica-supported WO3 as an efficient visible light photocatalyst for VOC removal

Volatile organic compounds (VOCs) pose a significant threat to indoor air quality (IAQ) and represent a serious risk to human health. Among available remediation strategies, visible-light-driven photocatalytic oxidation (PCO) emerges as a promising and environmentally benign technology for degrading VOCs, particularly at the low concentrations typical of indoor environments. Consequently, developing cost-effective, high-activity visible-light-responsive photocatalysts is paramount. In this study, WO 3 nanoclusters were supported on a mesoporous silica (m-silica) substrate to enhance gas-phase photocatalytic decomposition under visible light. The m-silica effectively acted as an active site enhancer by increasing surface area and suppressing electron-hole pair recombination. m-silica/WO 3 nanocomposites with varying loadings were synthesized via in-situ sol-gel and wet impregnation methods. Characterization by N 2 sorption confirmed the mesoporous structure, while XRD revealed crystalline monoclinic tungsten trioxide phases. TEM analysis demonstrated a uniform distribution of WO 3 within the m-silica matrix. Diffuse Reflectance Spectroscopy (DRS) confirmed the visible light activation capabilities of the composites. Among the evaluated compositions, the catalyst containing 70 wt.% WO 3 exhibited superior performance, achieving 97.3% toluene degradation within 4 hours under white LED illumination. Notably, in-situ synthesized samples outperformed those prepared via a wet impregnation method. The impact of platinum doping on the optimal catalyst was also investigated. Finally, the best-performing sample was coated onto a ceramic foam scaffold (CFSs), enabling stable, reusable, and efficient toluene degradation over multiple cycles.