Fluorinated Mesoporous Anatase TiO2 Microspheres with High Surface and Enhanced Photocatalytic Activity for the Degradation of Methyl Orange

Abstract

Highly crystalline mesoporous TiO₂ microspheres with areas up to 122 m²/g and tunable pore size have been prepared through a combined sol–gel and solvothermal processes. The concentration of NaF exhibits a great effect on the morphology, crystallinity, crystal size and photocatalytic activity of the TiO₂ microspheres. A higher NaF concentration results in an increase in the average crystal size and pore size, whereas whereas it caused a decrease in the specific surface areas. All fluorinated TiO₂ microspheres showed a higher photocatalytic activity than P25 and pure TiO₂ microspheres obtained in the absence of NaF due to the effect of surface fluorination on the photoactivity of TiO₂. The approach described in this study provides a simple method to synthesize the micrometer-sized hierarchical structure of mesoporous TiO₂ microspheres that are ready for practical applications such as environmental pollutants removal and solar cell because these high active materials can be easily separated.