The Research Of Interaction Between Nano Material Titanium Dioxide Films Doping Ions And Metal Substrates

The influences on nanometer titanium dioxide films doped thirteen metal ions on three substrates prepared by sol-gel methods are studied. The main result is as follows:1.The doping of ions with different concentrations and types influences the photoactivity of TiO2 films, in which Mn2+,Ni2+,Co2+ can reduce photoactivity of catalyst. When Co concentration is 6.04x10 / cm , the decolour rate of the solution has been reduced to 9.13% for aluminium slices carrier; for stainless steel carrier, the degradation rate is 7.32%; only a few ions can raise photoactivity of catalyst for titanium slice carrier, most ions have negative effects on phototactivity of TiO2 films. For instance when the concentration of Cr3+ is 6.04xl015 / cm3, the degradation rate is 70.79%; the optimum concentration of W6+ is6.04xl018/cm3.2.Doping ions can change the work function of the semiconductor , different metal doping ions with the same concentration change the work function of the semiconductor to different extent, thus schottky barrier is changed, which cause the different photoactivity of TiO2 films . For the titanium substrate, the effects of La3+,Cu2+ and Fe3+at the same concentration on photoreactivity of TiO2 film are obviously.3.Titanium slice, Aluminium slice, Stainless steel have different electric conductivity in the same thickness, and different work function (the work function of titanium is 3.98 eV, aluminium function is 4.25 eV , stainless steel function is 4.51 eV), those lead to different TiO2 intrinsic resistivity , which make electrons transfer to TiO2 films from basis material through interface. The difference of work function has determined the depth that the electrons shift to interfaces. Titanium slices carrier has minimum work function, and the ability to fetter the electron is relatively little, which make it easy transfer to semiconductor surface and react with the pollutant absorbed by the surface, however this conclusion is untenable for stainless steel carrier and aluminium slice, because there are certain relations between the value of Wm and metal superficial state.In general, the photoactivity of TiO2 films loaded on titanium is better than other metal carriers no matter what kind of ions are doped. Its degradation rate is better than other carriers under the same condition . This research shows important theory value and practical meaning specially for developing functional and composite nanometer titanium dioxide material.