Synthesize of porous TiO2 thin film of photocatalyst by charged microemulsion templating

Porous TiO2 thin film of photocatalyst was synthesized by charged microemulsion templating. In the process, cationic polystytrene microemulsion (PSTM) was successfully added into the precursor solution of TiO2 (Ti-sol). The factors, such as the charged surfactant species, the amount of PSTM and pH of the solution mixture strongly affect the stability of the solution mixture. TiO2 film containing larger pores in diameter of 20-100 nm was obtained after heat treatment and analyzed by BET and BJH. The addition of PSTM effectively influences crystal structure, specific surface area and morphology of thin films. The crystal particle growth of anatase phase is restrained by PSTM addition, and the addition of PSTM promotes the crystal phase transformation from anatase to rutile phase, as was testified by XRD, AFM and FT-IR. The photocatalytic degradation suggests that the optimal addition of PSTM (the volume ratio of PSTM and Ti-sol being 0.3) can reach a remarkable enhancement of photocatalytic activity of TiO2 films, shown by an increase of almost 66% of the apparent rate constant of degradation.