TiO2 / SiO2 composite films immobilized on foam nickel substrate for the photocatalytic degradation of gaseous acetaldehyde

Abstract

The photocatalyst anatase titanium dioxide (TiO 2) films were immobilized via sol-gel technique on foam nickel modified with SiO 2 films as transition layer (indicated as TiO 2 / SiO 2 films). The structural properties of TiO 2 / SiO 2 composite films were characterized using TG-DSC, XRD, FE-SEM, and BET. The photocatalytic activities of immobilized TiO 2 / SiO 2 films were tested through photocatalytic degradation reactions of gaseous acetaldehyde under ultraviolet (UV) light irradiation. The substrate modification with transition layer of SiO 2 films 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 100ppmv) on TiO 2 / SiO 2 photocatalysts reached 100 after 100minutes of irradiation. The photocatalytic activity of TiO 2 / SiO 2 films reduced about 15 after 9 consecutive runs, which was more stable than that of TiO 2 films, and was completely recovered after heating at 300 °C for 1hour.