Preparation Of Bismuth Titanate / Titanium Dioxide Heterogeneous Junction By Alcohol Thermal Method And Its Photocatalytic Activity

Heterojunction material integrates the advantages of heterostructures and nano-materials, which could expand the range of wavelengths wide band gap semiconductors and inhibit the recombination of electron-hole pairs, leading to the photocatalytic efficiency has been significantly improved in visible light, so it obtained a great deal of attention in the field of photocatalytic. This paper was committed to study preparation、characterization and photocatalytic properties of Bismuth titanate and TiO2heterojunction materials. The work is listed as the following three parts:The Bi2oTi032/Ti02composite heterojunction nanomaterials were prepared by solvent-thermal method, using ethanol and glycerol as solvent, Bi(NO3)3·5H2O and Ti(BuO)4as reactants. The prepared catalysts were characterized by XRD、TEM、 FE-SEM、HRTEM、XPS、UV-Vis and PL technology. The photocatalytic activity and reuse performance of catalysts were evaluated through photocatalytic decolorization of methylene blue (MB) aqueous solution. The results show that higher crystallinity Bi2oTi032/Ti02catalyst had synthesized when molar ratio of Bi and Ti was0.2, the volume ratio of ethanol and glycerol0.2. the synthesis temperature120℃and the calcination temperature500℃. The degradation efficiency of20mg/L methylene blue colud reach98.1%illuminated for3h under250W simulated sunlight and catalyst amount lg/L. In addition, the catalyst was easily separated from solution and the removal efficiency of MB still reached94.1%when the catalyst was reused for4times.Bi2Ti2O7/TiO2composite heterojunction nanomaterials were prepared by solvent-thermal method using ethanol and glycerol as solvent and Bi(and Ti(BuO)4as reactants. The prepared catalysts are characterized by XRD、 FE-SEM、TG-DTA、FT-IR、BET and UV-Vis. The samples photocatalytic activity was evaluated through photocatalytic decolorization of methylene blue (MB) aqueous solution. The results show that higher crystallinity Bi2Ti207/TiO2catalyst had synthesized when molar ratio of Bi and Ti was0.2, the volume ratio of ethanol and glycerol0.1. the synthesis temperature120℃and the calcination temperature600℃. The amount of glycerol in the solvent affects the structure and morphology of the products. The degradation efficiency of20mg/L methylene blue can reach99.1%illuminated for3h under250W simulated sunlight and the solvent volume was0.1. Photocatalytic degradation of Cefalexin and Tetracycline hydrochloride were studied with Bi2oTiO32/Ti02as catalyst under simulated sunlight. The influence of pH、initial concentration and catalyst amount on the removal efficiency of antibiotics were investigated. The results show that two antibiotics were photodegraded. Under the condition of the optimal initial pH, the initial concentration of Cefalexin and Tetracycline0.5g/L and catalyst dosage1.5g/L, the removal efficiency of Cefalexin and Tetracycline were93.1%and73.5%, respectively, The photocatalytic degradation reaction of Cefalexin and Tetracycline in simulated sunlight was basically agreed with first-order reaction kinetics.