Study On The Preparation Of The Multi-structural Titanium Dioxide And Its Photocatalytic Performance

With the development of industrialization,various organic wastewater pollutants have been discharged to our environment,which has endangered human health and the environment.Various advanced oxidation technologies,such as Fenton,ultrasonic,electrical-chemical,and photocatalytic technologies,have been proposed to treat azo dyes in wastewater.Among these wastewater remediation technologies,titanium dioxide is widely used due to its unique chemical structure,quantum size effect and photochemical properties,etc.However,the application has been limited for its lower phtocatalytic efficiency,large band gap only responded in the UV region,and easier to aggregation.Therefore,this study use metal and nonmetal co-doping,semiconductor compound,and macroporous titanium dioxide to improve the photocatalytic performance.First of all,the methyl orange solution was selected as model pollutant wirh concentration of 80 mg/L.The best preparation conditions of Mn-N/TiO₂ composite photocatalyst was investigated using single factor method and combining with various characterization technologies.The results indicated that the best preparation conditions was achieved at the following conditions: the molar ratio of tetrabutyl titanate and manganese nitrate is 0.0006,and the molar ratio of tetrabutyl titanate and urea is 0.2,and the molar ratio of tetrabutyl titanate and anhydrous ethanol is 10,and the molar ratio of tetrabutyl titanate and glacial acetic acid is 6,and the calcination temperature is 400 ?.The methyl orange degradation rate was 92% after 60 min under the visible light.In addition,3 DOM Gd/TiO₂ composite photocatalyst was prepared using SOL-gel method and characterized via various technologies.The effect of 3 DOM Gd/TiO₂ composite photocatalyst for the degradation of organic dyes wastewater was explored,and the results indicated that three-dimensional ordered macroporous structure can increase the contact area of the catalyst and the light,which is beneficial to improve the effect of titanium dioxide on the degradation of organic dye wastewater.Moreover,the macroporous structure of titanium dioxide can be easily recycled,and a removal efficiency of 73% was achieved after 60 min reaction under visible light.Finally,the nano titanium dioxide and the three-dimensional titanium dioxide were modified using polyaniline.In comparison,the photocatalytic activity of PANI-TiO₂ and 3 DOM PANI-TiO₂ was analysied.The experimental results indicated that PANI-TiO₂ and 3 DOM PANI-TiO₂ shift to the visible light region obviously,which enhancing the photocatalytic performance dramatically.Moreover,the composite photocatalyst can be recycled several times.