Titanium Dioxide Supported on Different Porous Materials as Photocatalyst for the Degradation of Methyl Green in Wastewaters

Abstract

TiO2 nanoparticles were immobilized on two porous materials used as catalyst supports, namely, activated carbon (AC) and natural clay (NC), through an impregnation process using TiO2 (P25) as precursor. The so-prepared composite materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transition electron microscopy (TEM), and nitrogen physisorption, that is, Brunauer-Emmett-Teller (BET) surface area determination. SEM and TEM observation evidenced that TiO2 was deposited on AC and NC surface. XRD results confirmed that TiO2 existed in a mixture of anatase and rutile phases. The specific surface area of photocatalysts decreased drastically in comparison with the original materials. The photocatalytic activity of these materials was assayed in the oxidation of Methyl Green (MG) dye in aqueous medium under UV irradiation. TiO2/AC exhibited higher photocatalytic oxidation activity than TiO2 at neutral pH. Total mineralization of MG was confirmed by means of COD analysis, pointing to these materials as an efficient, cost-effective, and environment friendly alternative for water treatment.