Preparation Of Nanometer TiO₂ Photocatalysis By Micro-arc Oxidation And Its Application Study

This thesis has been studied the availability of the photocatalysis TiO₂ which is preparatived by Micro-arc Oxidation (MAO) on the degradability of methyl-orange and lubricating oil in water, and the effect of its active under different conditions, then it has been application in dyeing waste water.The research includes: the method and characterization of TiO₂ photocatalysis prepared by MAO;the availability of TiO₂ photocatalysis and the effect of pH value and other ion(Fe³⁺ Fe²⁺ and Cl^-) in solution;the result of UV/US synergetic catalysis;adulterating metal into the photocatalysis by MAO method and the effect to activity of catalyst by this way;application of TiO₂ photocatalysis.The result show that:â‘ TiO₂ photocatalysis which prepared by MAO method in acidic bath has the structure of anatase and in nanometer;â‘¡TiO₂ photocatalysis by MAO method has well activity, when it is aerating the degradation rate of methyl-orange can arrive to 48.57% within 120min,and the degradation rate of lubricating oil in water can arrive to 89.76%;â‘¢Electrolyte density and electrolysis times have influence to the catalyst activity when the process of TiO₂ was made. The electrolyte density exists a best value, under the condition of the experiment of this thesis the best value for the phosphoric acid is 7.5 ml/ L;the electrolysis time will affect the thickness of the film layer;â‘£The pH in the aqua will have very big influence to the catalyst result, degradation rate of methyl-orange in acidity condition is higher than in alkaline condition, when pH is 4.0 the degradation rate is 92.15%;⑤The different ion in aqua will play different roles, such as the Fe³⁺ will rise the function of Fenton, adding the efficiency of catalyst and the best adding is 15mg/L;but the Clwill restrain the activity of catalyst, making de catalyst efficiency lower;â‘¥ TiO₂ photocatalysis making by MAO method show the high strength of bond in the UV/US synergetic catalysis, and the synergetic effect of US/UV was identified in degradation of methyl-orange, and increase the catalysis efficiency by 2l.41%;⑦aclding Ag⁺, Fe.Sn +, Sn4+, W, Mn and Cr in electrolyte it can obtain TiC>2 photocatalysis with adulterating metal, and it show that adding Ag, Sn2+, W can rise catalysis activity and the best adding value is 0.5g/L, 0.5g/L and 0.2g/L;(h)these catalysis(no matter adulterating metal or not) is applied in dyeing waste water and get the good result, after photocatalysis the dyeing waste water is reducing chromaticity and turbidity and clear. This thesis certify the feasible of preparation and modification the TiO2 photocatalysis by MAO, and it can be apply in practice.