Gas-phase photo-oxidation of organic compounds over nanosized TiO_2 photocatalysts by various preparations

摘要

Gas-phase photocatalytic oxidatio of hexane over nanosized TiO_2 catalysts with different specific surface area, particle size and crystal phase at ambient temperature was studied and compared with Degussa P25. The photo-oxidation products are CO_2 and H_2O, and the activity is dominantly dependent on the surface area of the catalysts, although the faster electron-hole recombination in smaller TiO_2 particles experts to a certain extent a negative effect on the photocatalytic process. No significant difference in the activity has been observed between pure anatase and rutile catalysts with comparable specific surface area of the catalysts, although the faster electron-hole recombination in smaller TiO_2 particles exerts to a certain extent a negative effect on the photocatalytic process. No significant difference in the activity has been observed between pure anatase and rutile catalysts with comparable specific surface area and particle size. Sulfatio of anatase TiO_2 catalysts improves their activity and stability efficiently. The complete oxidation of methanol and benzene to CO_2 and H_2O can also be achieved on the sulfated nanosized anatase photocatalysts successfully, and the catalysts are rather stable after reaching the steady state.