Preparation Of Titania Photocatalyst Supported On Carbon Fiber And Its Photocatalytic Activity Under Visible Light

The photocatalytic activity of TiO₂ can demonstrate only by the ultraviolet irradiation, due to its wide band gap. While, the powder TiO₂ also has other disadvantages, such as, incline to blow away in the air, conglobated in the water and hard to reclaim. That's severely limited its applications. Therefore, preparation of immobilized photocatalytic titanium dioxide photocatalyts and improvement of its photocatalytic activity under visible light are keys to expand the scope of practical applications. In this paper, the photocatalyst composites of TiO₂ thin film supported on polyacrylonitile based carbon fiber (PAN-CF) substrates was prepared by sol-gel dip coating technique and a suitable sol-gel process was explored. photocatalytic activity under visible light obtain via ion-doping. The doping ions affect on the structrure and photocatalytic under visible light of photocatalyst were studied. To improve the load performance and the photocatalytic under visible light of material, The TiO₂/CF potocatalyts are prepared by a new heat treatment processes under used to preparation of steam ambient instead of N2 atmosphere.The TiO₂/CF potocatalyts are prepared by different sol systems on the basis of the multicomponent system phase diagram theory of Ti(OC₄H₉)₄-C₂H₅OH-H₂O and different heat treatment temperatures, then annealing in steam ambient. The structure and properties of TiO₂/CF was researched. The results showed that the average grain size of TiO₂ films is between 73nm and 100nm. The steam ambient treated TiO₂/CF potocatalyts have showed higher photocatalytic activity than the N2 ambient treated TiO₂/CF photocatalyts on degradation of Acid Orangeâ…¡under ultraviolet irradiation.The TiO₂/CF potocatalyts was modified by Gd-doping, and the effects of Gd-doping and annealing ambient on the structure and photocatalytic activity of TiO₂/CF potocatalytsis were researched. The results showed that Gd-doping not only enhanced the absorption capacity of the TiO₂/CF materials effectively, but also made water and hydroxy adsorbed on the surface of TiO₂/CF more easily. When W(Gd)/W(Ti) is 0.75%, the photocatalytic activity of material under visible light was improved effectively. But the result was contrary when under UV light. Compare to heat treatment processes under air and N2 ambient, the photocatalytic activity of TiO₂/CF potocatalyts treated under steam ambient is better increased.Based on Gd-doped and Gd/Fe-doped, Gd/Fe/S-doped were chosen to modify the TiO₂/CF photocatalysis materials to improve its photocatalytic activity under visible light. The results showed that compare to Gd-doped, Gd/Fe and Gd/Fe/S co-doped has a synergy affect. it's not only extend the absorption light wavelength, increase the utilization of visible light, but also give the TiO₂/CF photocatalysis materials more obvious porous structure. It was conductive to adsorption of target degradation and enhance photocatalytic activity of materials under visible light. It removes 70.63% of acid orangeâ…¡after 2.5 hour reaction.