Post Treatment Technique Of TIO₂/TI Films And Effects On The Photo Catalytic Property For H₂ Production

In this paper, TiO₂ film catalysts prepared on TA1 titanium substrate with a plasma electrolytic oxidation (PEO) were treated by gaseous penetration and chemical impregnation methods. We studied the influence of gaseous penetration and chemical impregnation process conditions on the photocatalytic properties of TiO₂ films. Then the treated TiO₂ films were characterized and the photocatalytic activity of the film catalysts was evaluated.Scanning electron microscopy (SEM), X-ray scattering spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible spectrophotometer (DRS) and other tests were used to study the film catalysts. The effects of treated TiO₂ films on the structure, composition and optical absorption property were investigated along with their inherent relationships. Moreover, the photocatalytic activity of the film catalysts for splitting Na₂S(0.1M)+Na₂SO₃(0.02M) solution into H2 by an external side UV-A high-pressure mercury lamp were also evaluated.The results show that, compared with untreated TiO₂ film, the spectrum absorption edge of the TiO₂ films treated with permeated C shift to red, the pore size of the discharge channel on the films surface was decreased, and the peak of anatase TiO₂ move to small angle. Photocatalytic hydrogen production experiments show that the optimization conditions were: the amount of rare earth is 0.2g, the diffusion temperature is 650℃, and the cooling mothed is furnace cooling. In addition, we investigated the influence of urea and silver nitrate addition on the photocatalytic properties, the results show that when the quantity of urea was 2.0g, the quantity of silver nitrate is 0.5g, the photocatalytic properties of the film catalysts were increased than the untreated TiO₂.To TiO₂ film catalyst treated with impregnation of rare earth ion Ce³⁺ approach, it's spectrum absorption edge shifted to red, the surface pore size was decreased, and the anatase TiO₂ peak moved to small angle. Photocatalytic hydrogen production experiments showed that when the soaking time was 6h, the film photocatalytic properties were improved greatly. Precious Metals Ag was loaded on TiO₂ film catalyst by chemical impregnation method, and then reduced through reducing agent and reducing atmosphere ways respectively. After loading Ag, the absorption peak intensity of the films has increased, and the spectrum absorption edge of Ag/TiO₂ reduced by reducing atmosphere shift to long wavelength, while the spectrum absorption edge of Ag/TiO₂ reduced by reducing agent shift to short wavelength, the anatase TiO₂ peak shift to the small-angle, and the active of the photo catalytic property for hydrogen production has been enhanced, which is because impregnate with precious metals Ag can separate electrons and holes.