Preparation,Characterization,and Optical Properties Of Nano TiO₂ Thin Films On Substrates And ACF

Titanium dioxide semiconductor as the most common photo catalyst has the advantages of high photocatalytic activity,stable chemical properties and low cost,and has been widely used in photocatalytic oxidation and reduction of target pollutants.However,the traditional nanometer titanium dioxide photo catalyst is in the carrier-free powder state,which is very easy to agglomerate and is difficult to be used as the photo catalyst effectively.In this paper,the physical structure stability and photocatalytic performance of nano titanium semiconductors were improved by changing physical structure and carrier selection.The photo-induced super-hydrophilicity and film morphology of nanometer titanium dioxide films on different substrate types were studied.The physical stability and photocatalytic activity of TiO₂/ACF composites were studied.The results show synergistic effect of ACF strong adsorption capacity and nanometer titanium dioxide photo catalysis was fully realized.?1?Nano TiO₂ thin film composites were immobilized on different substrates on molecular level via in situ reverse micellar.The effect of n?H2O?/?surfactant?,aging time and calcination temperature etc.on nano TiO₂ thin films were investigated.The photo induced super hydrophilicity,adhesion and stability of nano TiO₂ thin films were studied.The surface morphology,thickness and crystal morphology of nano TiO₂ thin films were investigated by SEM,UV-Vis-NIR spectrophotometer and XRD.Finally,the photo-induced super-hydrophilicity of nano TiO₂ films on the surface of the substrate was measured by video contact angle tester.?2?TiO₂/ACF photocatalytic composites were prepared via nano TiO₂ thin films supported on activated carbon fibers.There are strict requirements for thickness of the Nano TiO₂ thin films because the diameter of general ACF is 10—30?m.The optimum thickness of nano TiO₂ thin films is tens of nanometers to two hundred nanometers.The physical morphology,crystal structure and loading rate of TiO₂/ACF composites were characterized by SEM,XRD and TG-DSC.The results show that the optimal concentration of titanium ions in the in situ induced reverse micellar solution is 0.21?0.25M,and the aging temperature has a great impact on thin films physical morphology.Finally,the photocatalytic decomposition of methylene blue solution of TiO₂/ACF composites was carried out.When the photocatalytic time was 5min,the decomposition rate was 86.4%.And catalytic time was 60min,which was 20%higher than that of the original ACF felt.?3?The photocatalytic activity and structure stability of TiO₂/ACF composites were studied.Besides,the continuous photocatalytic treatment of wastewater and recycle efficiency were studied.The results show that the nano films with a certain thickness on the surface of ACF can realize its strong adsorption capacity and titanium dioxide photocatalytic synergistic effect.TG was used to analyze the loading rate and film stability of the composites.The results show that the Nano films have stable nanostructures on the ACF surface.The photocatalytic efficiency of TiO₂/ACF composites after recirculation is basically not changed.The average decomposition rate of methylene blue solution was 2.56mg/h,and the treatment time was 32h.