Study On The Application Of TiO₂ In Photocatalytic Degradation Of Methyl Orange And Photoelectrode Of Dye Sensitized Solar Cell

As an important semiconductor, TiO₂ plays a more and more significant role in photocatalytic degradation and dye-sensitized solar cell (DSSC). TiO₂ particles with nano size can have larger specific surface areas, which is in favor of pollutants'or dye's adsorption. However, present methods of preparing nano-TiO₂ have such shortcomings as they need conditions like high temperature, high pressure and complicated treatment. What's more, the nano-TiO₂ fabricated in powder shape can hardly be attached to carrier, which can bring secondary pollution since they are difficult to be recycled.Here we introduce a novel approach of preparing TiO₂ films on conductive substrates at low temperature by electrophoretic deposition method without successive calcinate treatment. The photocatalytic activity of the non-calcinated TiO₂ film was evaluated by degradation rate of methyl orange (MO). It was found that the degradation rate of MO increased with the amount of TiO₂, and it was higher in both acidic and alkaline media than under neural condition. In addition, lower pH was more favorable for the degradation of MO. The photocatalytic degradation of MO could be described as pseudo-first order reactions. When the initial concentration of MO increased from 1 mg/L to 10 mg/L, the highest degradation rate was achieved at 5 mg/L. The apparent reaction rate constant was calculated to be 0.0098 min?1. Fe-doped TiO₂ could significantly improve its photocatalytic efficiency.In the study of dye-sensitized solar cell modules, we conducted series of associative experiments on the modification of the TiO₂ photoelectrode to expect a better performance. P-25 TiO₂ powder was used in preparing paste; the conversion efficiency was increased from the initial 1.41% to 2.48% by the optimization of paste additive. In the second step, a merchandised paste with smaller particle size was introduced to fabricate a double-layer cell with the P-25 paste; the final result was quite satisfactory with a sharp increase in the conversion efficiency of 5.26%.