Modified sol-gel/hydrothermal method for the synthesis of microsized TiO2 and iron-doped TiO2, its characterization and solar photocatalytic activity for an azo dye degradation

Abstract

TiO2 and iron-doped TiO2 microsized powder is prepared by sol–gel method combined with hydrothermal treatment as an alternative to obtain high specific area under controlled conditions. Synthesis parameters such as temperature of hydrothermal treatment (125 °C–210 °C), calcination temperature (500 °C–900 °C), and calcination time (1 h–9 h) along with operational parameter as solution pH (3, 7 and 9) in the solar photocatalytic reaction are assessed. TiO2 and iron-doped TiO2 micro powders are characterized by XRD studies, FE-SEM, specific area BET and photocatalytic activity by basic orange 2 (BO2) mineralization under solar irradiation. Results showed that ultrafine anatase microspheres are generated by sol-gel/hydrothermal treatment. Iron-doped TiO2, prepared by consecutive steps such as sol-gel/hydrothermal treatment at 200 °C, washed with ethanol, followed by calcination at 600 °C and dried with a rotary evaporator, showed the highest discoloration and mineralization of BO2. Outstanding performance is observed when compared with commercial TiO2 (Hombikat).