Preparation Of Loaded TiO₂-Ag-Ce Catalyst And Research Of Its Photocatalysis Properties

With the development of industry, more and more different chemical sysnthesis organic that toxic, carcinogenesis and threat to human's healthy enter into water through different kinds of ways, which made serious pollution in water enviroment. As a kind of new wastewater treatment method, TiO₂ photocatalyst has many advantages, such as high efficiency, high oxidative ability etc. But it also has many problems such as low photocatalytic rate, low utalization ratio of visible light, difficult to use repeatedly.This paper aimed at enhancing the photocatalysis properties and repeated usage rate of nano-TiO₂. Studied the preparation conditions of nano-TiO₂, nano-TiO₂ doped with noble metal ions Ag+ and rate earth ions Ce3+, loading it using caramic and glass and using supporting catalyst degradate methyl orange and phenol wasterwater. Doped and loaded samples were characterized by scanning electron microscopy (SEM).(1) The L9(34) Orthogonal Design experimental results show that the optimum hydrolysis temperature is V(H2O):V(HNO3):V(C2H5OH):V[Ti(OC4H9)4]=0.3:0.04:3.5:1, and the sequence of each influcing factor is: dosage of wate>amount of nitric acid > dosege of ethanol.(2) The reach of ion doping TiO₂ was studied. For the Ag+ doping TiO₂ photocatalyst, the particle is uniform and particular, when added amount of Ag+ doping ions was 0.03%, calcination temperatures was 400℃, calcination time was 4 h the photocatalytic activity reached the maximum; For the Ce3+ doping TiO₂ photocatalyst, the particle is more uniform than Ag+ doping TiO₂, when added amount of Ce3+ doping ions was 0.03%, calcination temperatures was 500℃, calcination time was 4 h the photocatalytic activity reached the maximum; For the Ag+ and Ce3+ co-doped TiO₂ photocatalyst, when added amount of co-doping ions was 0.05%, m(Ag):m(Ce)=1:3, calcination temperatures was 550℃, calcination time was 4 h the particle is the most uniform in the all photocatalyst, and the photocatalytic activity reached maximum, and higher than Ce3+ doping TiO₂ photocatalyst.(3) Study of T-AC/vector service life showed, T-AC/ ceramic has greatest photocatalysis when the coating time is 3 times. And the degradation rate of methyl orange which concention is 10 mg/L reached 84.5%. T-AC formed favorable film on the ceramic surface. T-AC/ glass has greatest photocatalysis when the coating time is 4 times. And the degradation rate reached 73.3%. T-AC distributed uniforom on the glass surface. Ceramic has a better load ability than glass.(4) The photodegradation of methyl orange effluent was investigated. The degradation rate of methyl orange solution can reach to 85.9% when pH value is 2, the concentration of H2O₂ is 0.5 mL/100 mL, the dosage of T-AC/ceramics is 3 g/L, Uv-light intensity is 20 W, the initial concentration of methyl orange is 10 mg/L and the reaction temperature is 30℃.(5) The photodegradation of phenol wasterwater was investigated. The degradation rate of phenol can reach to 80.9% when initial concentration of phenol is 10 mg/L, pH value is 2, and the amount of T-AC/ceramics is 7 g/L.(6)The experiment shows that the T-AC/caramics has good catalyst life and stability. The degradation rate of methyl orange and phenol shows fluctuating changes. The maximum degradation rate of methyl orange is 85.9%, the minimum is 80.3%, and the average value is 83%; The maximum degradation rate of phenol is 80.9%, the minimum is 75.2%, and the average value is 77.8%.(7) Kinetic equation was studied。The result showed when the initial concentration of Methyl orange and phenol is low that Methyl orange and phenol photocatalytic degradation reaction all could be expressed by first order kinetics.