Sepiolite-TiO2 nanocomposites were synthesized by conventional calcination process and microwave hydrothermal (M-H) treatment and were tested and compared for their photocatalytic activity. XRD analysis indicated that nanocomposites after calcination at 500 °C or M-H treatment for 40 min at about 200 °C appear to be the optimal conditions, which assured the amorphous TiO2 to crystalline anatase phase transition. The deposition of the TiO2 on the surface of sepiolite by M-H treatment yielded small dispersed nanoparticles at all treatment times used in this study. However, TiO2 particle size increased with increasing calcination temperature, which was confirmed by SEM and TEM. N2-adsorption-desorption isotherms indicated that calcination process reduced the specific surface areas of the nanocomposites while the M-H treatment led to a higher surface area with better photocatalytic performance for the degradation of Orange G. The intact structure of sepiolite and the homogeneous dispersion of the TiO2 nanocrystals on sepiolite surfaces led to enhanced photocatalytic activity in M-H treated samples.
All Science Journal Classification (ASJC) codes
- Geochemistry and Petrology