The Photocatalytic Performance And Calculation Of Rare Earth、Non-metal Doped TiO₂

Nano TiO2semi-conductive material, which is known for its strong redox ability, stability, non-toxicity, and low-cost, has drown more attention from researches in the application of solar energy. Moreover, it has been widely used to degrade organic pollutant sewage. However, due to its relatively large band-gap (3.2eV), TiO2is only capable of utilizing UV-light in the sunlight (which only accounts for3-5%of solar energy). On the other hand, easy recombination of photo-induced electrons-holes and the lower efficiency of photo quantum increased the technical difficulties of applying TiO2as photocatalyst in large scale.In the experiment, butyl titanate was used as precursor of Ti, glacial acetic acid as hydrolase inhibitor, ethyl alcohol as solvent. Sol-gel method was applied for the preparation of Nano TiO2, and Eu doped (doping amount:0.5%,1%,2%, and3%), and B doped (doping amount:1%,2%, and3%) photocatalyst. XRD indicated that all the products were anatase TiO2, and doping was beneficial for decreasing the grain size. Combined with the FT-IR results, it is believed that Eu3+was scattered in TiO2in the form of oxide. From the enlarge figure of the first main XRD spectrum of, it can be observed that there was a right shift of the diffraction on the crystal plane (101) comparing with the pure TiO2. It can be concluded the shrinkage of TiO2unit cell caused by invasion of B into TiO2lattice. This provided that the existing form of B in TiO2lattice can only be the oxygen atom was replaced with B. The photocatalysis experiments indicated that2%Eu3+doped catalyst is the optimized catalyst (the rate of degradation is78%in3hours) when3g/L Eu doped catalyst was added and the initial concentration of rhodamine B was12mg/L. And2%B doped catalyst is the optimized catalyst (the rate of degradation is72%in3hours) when3g/L B doped catalyst was added and the initial concentration of rhodamine B was12mg/L.Materials studio was employed to asimulate B doped TiO2based on the first principal for model structuring and geometric optimization. Theoretical calculation was accomplished using CASTEP. The calculated band gap for pure TiO2was2.138ev, and the band gap for0.7%B doped TiO2was2.098ev. The density distribution was also generated. The numerical result coincided with the previous experiment, and thus we concluded that B dope can decrease the band gap of TiO2.