Photocatalytic performance of combustion-synthesized β and γ-Ga2O3 in the degradation of 1,4-dioxane in aqueous solution

Nanostructures of beta and gamma-Ga2O3 were prepared by the solution combustion route using urea as fuel. The synthesized nano photocatalysts were characterized by use of XRD, FT-IR, BET, TEM, TGA-DTA, DRS, and Raman spectroscopy. XRD and TEM investigations confirmed the nanostructures; particle size was in the range 3-5 nm for gamma-Ga2O3 and 40-50 nm for beta-Ga2O3. The specific surface area of gamma-Ga2O3 was 91 m(2) g(-1) and that of beta-Ga2O3 was 24.3 m(2) g(-1). The polymorphs of gallium oxide were used as photocatalysts for decomposition of 1,000 mg/l 1,4-dioxane. More than 90 % of the 1,4-dioxane could be degraded in less than 180 min by use of 10 mg/l photocatalyst + 0.5 ml H2O2. The efficiency of photocatalytic degradation of 1,4-dioxane by the synthesized photocatalysts was compared with that of P-25 TiO2 and followed the order gamma-Ga2O3 a parts per thousand yen beta-Ga2O3 > P-25 TiO2. The degradation was found to follow pseudo first-order kinetics.