TiO2/SiO2Composite Films Immobilized on Foam Nickel Substrate for the Photocatalytic Degradation of Gaseous Acetaldehyde

The photocatalyst anatase titanium dioxide (TiO2) films were immobilized via sol-gel technique on foam nickel modified withSiO2films as transition layer (indicated asTiO2/SiO2films). The structural properties ofTiO2/SiO2composite films were characterized using TG-DSC, XRD, FE-SEM, and BET. The photocatalytic activities of immobilizedTiO2/SiO2films were tested through photocatalytic degradation reactions of gaseous acetaldehyde under ultraviolet (UV) light irradiation. The substrate modification with transition layer ofSiO2films improved the specific surface area (SSA) of substrate and the acetaldehyde adsorption on photocatalyst film enormously and resulted in great enhancement of photocatalytic activity and stability. The degradation ratio of gaseous acetaldehyde (concentration of 100 ppmv) onTiO2/SiO2photocatalysts reached 100% after 100 minutes of irradiation. The photocatalytic activity ofTiO2/SiO2films reduced about 15% after 9 consecutive runs, which was more stable than that ofTiO2films, and was completely recovered after heating at300∘C for 1 hour.