Effect of surface state properties of TiO2 nanoparticle film on its photocatalytic activity

TiO2 nanoparticle film catalysts with different thicknesses were prepared b y plasma-enhanced chemical vapor deposition(PECVD) method and the surfaces were subsequently treated by TiCl4 or O-2 plasma. Two kinds of TiO2 films w ith different surface properties were obtained. Their surface microstructur es and energy levels of surface states were tested by AFM, XRD, SPS, The ph otocatalytic activities of the catalysts were determined via photodegradati on experiments of phenol. The results demonstrated that photocatalytic acti vities of samples whose surface was treated by O-2 plasma were greater than those treated by TiCl4 plasma. Moreover, photodegradation ratio of phenol during the first hour catalyzed by 0. 17 mu m thickness TiO2 nanoparticle f ilm was greater than other samples. Especially, the difference of photocata lytic activities of TiO2 nanoparticle films treated by TiCl4 or O-2 plasma was respectively explained by energy band theory.