Synthesis of TiO2/SBA-15 photocatalyst for the azo dye decolorization through the polyol method

The nano-sized TiO2 powder and immobilized TiO2/SBA-15 photocatalysts were synthesized via a polyol method with an attempt to increase the quantitative effect by reducing the particle size and avoid the aggregation by immobilizing on hydrophilic SBA-15 support. The effect of reduction temperature on the TiO2 crystalline size was investigated. The X-ray diffraction (XRD) and Field-emission scanning electron microscopy (FE-SEM) results showed that the crystallite size of the TiO2 particles is in the nano-regime and indicated that depended on the nucleation and growth process, different sizes and shapes of monodisperse or polydisperse TiO2 powders are formed. The photocatalytic activities of the samples were evaluated for the decolorization of an ano dye, acid red 1 (AR1) were studied in aqueous solution under UV light irradiation. The effect of different parameters such as catalyst dosage, solution pH, TiO2 loading weight, and different support materials Al2O3 and glass bead on the decolorization efficiency of AR1 were studied. The results indicated that the self-synthesized TiO2 showed comparable decolorization efficiency than commercial P25, and the efficiency can be significantly improved by using SBA-15 as support material due to its hydrophilicity.

► The TiO2 was synthesized via polyol method to increase the quantitative effect.
► By immobilizing the nano-sized TiO2 on hydrophilic SBA-15, the aggregation was avoided.
► The crystalline size and surface charge of TiO2 have influences on AR1 degradation.
► The 2,3-butanedione was adsorbed on the surface of TiO2 during the polyol process.
► The electrophilic at carbon of ketone may attributed to the adsorption of AR1.