Phosphate Modification Of Nano Tio <sub> 2 </ Sub> Photoelectrochemical Properties Of Research

The photoelectrochemical properties of TiO₂ have been widely studied since the low cost and high stability of TiO₂, and the energetics of the valence and conduction bands of TiO₂ which are suitable for contamination oxidation to purify the environment and proton reduction to solve the energy problem, respectively. The practical use of TiO₂ as water splitting and pollutant control materials is, however, limited due to the high energy of the band gap transition. This limits the absorption of TiO₂ to the UV region. A low quantum yield for photo carriers following the absorption of UV photons further limits the use of TiO₂ for photoelectrochemical water splitting. Numerous studies have attempted to overcome these shortcomings and to increase photoelectrochemical efficiency. In this paper TAS has been used to explore separation and transmission of nc-TiO₂ which is modified by phosphate and cobalt phosphate, and then the mechanism has been deeply penetrated.Phosphoric acid modification nanosized TiO₂ has been prepared by a sample impregnation method. The results show that an appropriate amount of cobalt phosphate modification could improve the photoelectrochemical activity of nc-TiO₂, which is attributed to the surface negative charge on the surface of TiO₂ after acid modification. The TAS results shows that phosphoric acid modification prolongs the life of carrier, and this is attributed to the surface negative charge on the surface of TiO₂, then the separation rate of photo electrons and photo holes are improved. The results were favorable to reveal the reason of the enhancement of photoelectrochemical current density of TiO₂ film electrode which corresponding to water splitting has been improved.Cobaltous phosphate modification nanosized TiO₂ has been prepared by a sample impregnation method.The results show that an appropriate amount of cobalt phosphate modification could improve the photocatalytic activity of nc-TiO₂, which is attributed to its holes have been trapped by low price cobalt ions, so that recombination of the holes and the electrons can be inhibited. The low price cobalt ions can be oxidized by holes to form high price cobalt ions, and high price cobalt ions oxidize water directly to form oxygen, which can promote the separation of photogenerated electron-hole pairs.This study has provided some reference methods and ideas for designing and synthesizing high performance TiO₂ based photoelectrochemical material and provided some important experimental basis for enrich the theory of TiO₂ photocatalytic technology.