Abstract:
TiO
2/ Fe
2O
3 and TiO
2/ Fe
2O
3/ SiO
2 nanocomposite photocatalysts were prepared with Na
2SiO
3 ·9H
2O , Fe(NO
3 )
3·9H
2O and TiCl
4 as precursors by chemistry coating processes and supercritical fluid drying (SCFD ) methods. Thephotocatalytic activity was evaluated by photocatalytic degradation of phenol as model reaction. Characterizations withXRD , TEM and FTIR show that in addition to anatase type TiO
2 is also formed in the range of the studied doping concentration , and SiO
2 remains amorphous at all samples. It could hold up the growth of the nanoparticle size and transformation from anatase to rutile. Compared with pure TiO
2 , or TiO
2/ Fe
2O
3 catalyst prepared by sol-gel method , nano-composite photocatalyst shows significant improvement in catalytic activity : The photocatalytic degradation rate of phenolin 6 h reached 9519 %. The optimum doping of Fe
2O
3 is 0106 %. Application of the TiO
2/ Fe
2O
3/ SiO
2 composite catalysts for the photocatalytic decomposition of phenol could not only give the same activity relative to pure ultrafine TiO
2 ,but also reduce cost . The experimental results prove that the thermal stability of TiO
2 is greatly enhanced after mixingwith slight amount of SiO
2 . The optimum doping of SiO
2 is 1010 %. The photo-catalytic particles prepared by SCFD combination technology have small size , large surface area and high activity.