Effect of TiO2 powder addition on sonochemical destruction of 1,4-dioxane in aqueous systems

Effects of TiO2 powder addition on sonochemical destruction of 1,4-dioxane in water were investigated through comparison of a SiO2 powder that had similar specific surface area. Results show that addition of TiO2 is more effective for decomposition of 1,4-dioxane in water than addition of SiO2. The contribution of photocatalytic destruction through sonoluminescence is not a dominant mechanism for acceleration of sonochemical reactions by adding TiO2. Sonication of TiO2-added water generated thermally excited holes in this case. Moreover, intrinsic oxygen vacancies in TiO2 surface play an important role in achieving high decomposition efficiency by producing cavitation. The addition of reduced TiO2 powder increases both the ultrasonication energy that is consumed in water and the destruction efficiency of 1,4-dioxane.