Electrospinning Preparation And Photocatalytic Properties Of Bismuth Titanate And Its Composite Nanomaterials

In recent years,bismuth titanate have been widely investigated as photocatalysts because of their unique electronic band structure and high photocatalytic activities.Its suitable band structure has also become a good intermediate for composites,so bismuth titanate are used in combination with other semiconductor materials to improve the photocatalytic performance.In our work,Bi₁₂TiO₂₀/Bi₄Ti₃O₁₂ composite nanofibers were preparated by using the self-made electrospinning apparatus and then combining hydrothermal method and a simple deposition-precipitation reaction produced MoS₂/Bi₁₂TiO₂₀/Bi₄Ti₃O₁₂,Ag₃PO₄/Bi₁₂TiO₂₀/Bi₄Ti₃O₁₂ composite nanofibers.The photocatalytic properties of the prepared products were tested with organic dyes as the target pollutants.The phase,component,morphology and absorptivity of the prepared samples were characterized by XRD,TEM,SEM,PL and UV-vis.The inhibitory effects of different trapping agents on the active intermediates in the photocatalytic reaction and the kinetic equation were discussed.The main research content is as follows:?1?Bi₁₂TiO₂₀/Bi₄Ti₃O₁₂ composite nanofibers were preparated by using electrospinning apparatus with Bi?NO₃?₃·5H₂O,tetrabutyl titanate,ethanol,DMF,citric acid and PVP as raw materials.The effects of polyvinylpyrrolidone and spinning voltage on spinnability,calcination temperature and heating rate on the photocatalytic performance were systematically studied.The results as follows: when the spinning voltage was 25 k V,the content of PVP was 0.107 g·mL-1,the calcination was 500 ? and the heating rate was 3 ?·min-1,Bi₁₂TiO₂₀/Bi₄Ti₃O₁₂ composite nanofibers with porous morphology and good photocatalytic activity can be prepared.Under the simulated sunlight?800 W xenon lamp?irradiation 40 min,the degradation rate of MO can reach 97.6%.The other used BQ,IPA,Na₂-EDTA were used as capture agent of different reactive intermediates,and the photocatalytic mechanism of Bi₁₂TiO₂₀/Bi₄Ti₃O₁₂ composite nanofibers was discussed.The kinetic studies show that the kinetic equation of degradation of MO with Bi₁₂TiO₂₀/Bi₄Ti₃O₁₂ composite nanofibers as photocatalyst is in accordance with the quasi-first order kinetic equation.The total hydrogen production was up to 187.82 ?mol·g-1 at 24 h after simulated sunlight?300 W xenon lamp?with Na₂S and Na₂SO₃ as sacrificial reagents.?2?Bi₁₂TiO₂₀/Bi₄Ti₃O₁₂ composite nanofibers were preparated by using electrospinning apparatus with Bi?NO₃?₃·5H₂O,tetrabutyl titanate,ethanol,DMF,citric acid and PVP as raw materials.On this basis,combining hydrothermal method produced MoS₂/Bi₁₂TiO₂₀/Bi₄Ti₃O₁₂ composite nanofibers,Na₂MoO₄·2H₂O and thioacetamide as raw materials.The results as follows: MoS₂/Bi₁₂TiO₂₀/Bi₄Ti₃O₁₂ composite nanofibers can be prepared when the mass percentage of MoS₂ is 12% and the hydrothermal temperature is 200 ?.After irradiation for 80 min,the degradation rate of MO solution can reach 98.37%.The total hydrogen production was up to 402.68 ?mol·g-1 at 24 h after simulated sunlight with Na₂S and Na₂SO₃ as sacrificial reagents.?3?Bi₁₂TiO₂₀/Bi₄Ti₃O₁₂ composite nanofibers were preparated by using electrospinning apparatus with Bi?NO₃?₃·5H₂O,tetrabutyl titanate,ethanol,DMF,citric acid and PVP as raw materials.On this basis,combining deposition-precipitation reaction produced Ag₃PO₄/Bi₁₂TiO₂₀/Bi₄Ti₃O₁₂ composite nanofibers,AgNO3 and Na₂HPO₄·12H₂O as raw materials.The results as follows: Ag₃PO₄/Bi₁₂TiO₂₀/Bi₄Ti₃O₁₂ composite nanofibers can be prepared when the molar ratio of Ag₃PO₄ and Bi₁₂TiO₂₀/Bi₄Ti₃O₁₂ is 1:1.After irradiation for 6 min,the degradation rate of MB solution can reach 97.8%.The kinetic studies show that the kinetic equation of degradation of MO with Ag₃PO₄/Bi₁₂TiO₂₀/Bi₄Ti₃O₁₂ composite nanofibers as photocatalyst is in accordance with the quasi-first order kinetic equation.