TiO2 thin films were synthesized by using Chemical Vapor Deposition (CVD) method on different substrates, such as glass, aluminium foil , and ceramic. The samples had been characterized by microscopy analysis, SEM, and EDS. The results show that TiO2 thin films were successfully fabricated and TiO2 nanocrystals with size of 50-100 nm loaded uniformly on surface of different substrates. The photocatalytic activities of all samples were investigated in photo-degradation of methyl orange (MO) under UV light irradiation and was followed by the UV-Vis diffuse reflectance spectroscopy, showing that the conversion of methyl orange achieved the highest percentage of 91% with TiO2 thin film synthesized on the ceramic substrate over 270 minutes of reaction. The hypothetical mechanism explaining this observation is that the surface morphology of ceramic plays a major role in the augmentation of MO molecules adsorption onto the surface of material, thus, improves the dye degradation process.

The photocatalytic reaction using TiO2 suspended to degrade the residues of toxic organic compounds has been extensively studied, but the ultilization of this process has not been recorded on an industrial scale. One of the primary reasons is the separation of TiO2 catalyst from the treated solution mixture. Conventional mechanical separation methods such as centrifugation, flocculation-deposition do not allow for thorough separation and catalytic reuse, whereas the microfiltration / ultrafiltration membrane process has been demonstrated to be capable of composting isolates very suspended particles. Accordingly, in this study, an experimental system separating TiO2-P25 suspension by microfiltration membrane 0.2 µm on laboratory scale was set up. Effects of operating factors: TiO2 concentration, pH value, transmembrane pressure and crosss flow velocity were investigated. Result shown that TiO2 concentration greater than 1 g / l will fundamentally diminish the permeate flux, futhermore, in the transmembrane  pressure differential (∆P) fluctuating from 0.3 to 1.2 bar, the relationship between J and ∆P is a linear relationship. In addition, the study likewise shown that the formation of the cake layer (scale) on the membrane surface is the fundamental driver of the permeate flux degradation over time. These results are the basis for integrating membrane and photocatalytic processes into a complete system for degradation toxic organic compound residues.