Low-temperature synthesis of photocatalytic TiO2 thin film from aqueous anatase precursor sols

Anatase TiO2 sols (RS) were synthesized by peptizing the hydrolysis of titanyl sulfate in abundant hydrogen peroxide solution and subsequent reflux to enhance crystallization. The influences of various reflux time on crystallinity, morphology, and size of the obtained TiO2 sol and dried TiO2 film particles were investigated. At room temperature, crystalline TiO2 thin film was deposited on glass silde from the as prepared TiO2 sol by dip-coating method. No further thermal posttreatment was required to eliminate organics from the film or to induce titania crystallization. TiO2 thin film on substrates could be thickened by means of consecutive dip-coating process. Titania film thus obtained was transparent and showed proper adherence. The photocatalytic activities of the TiO2 thin film was assessed by the degradation of methyl orange in aqueous solution. The preparation process of photocatalytic TiO2 thin film was quite simple and a low-temperature route.