Dicarboxylic acids as soft templates for the sol-gel synthesis of mesoporous nano TiO2 with enhanced photocatalytic activity

Abstract

We have synthesized TiO2 nanoparticles by sol-gel method utilizing different dicarboxylic acid modifiers viz. oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, malic acid and tartaric acid and compared their properties. The synthesized particles were characterized by Fourier transform infra red spectroscopy (FTIR), ultraviolet diffuse reflectance spectroscopy (UV-DRS), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive X-ray (EDX) and Brunauer-Emmett-Teller (BET) surface area measurement. The results indicate that the phase purity of the particles depend on the nature of precursor dicarboxylic acid. The synthesized samples were compared with Degussa P25 for photocatalytic activity by direct sunlight degradation of methylene blue. Samples prepared from malonic and glutaric acid precursors were found to show better photocatalytic activity than the P25 and were found to have maximum mesoporosity, smaller size and exclusive anatase phase.