TiO 2 /InStudy On The Sterilization Characteristics Of 2 O 3 Composite Semiconductor Heterojunction

With the time change and economic development, human being's contribution to science and technology is more and more perfect. But some microorganisms which threat to human life and health such as bacteria and viruses have not been eliminated. The spread of virus such as “Zika virus” and “Ebola virus” make human being helpless. Scientists from various fields try to develop a multitude of types of antibacterial products, including the semiconductor photocatalyst. As a matter of fact, the semiconductor photocatalyst not only can sterilize effectively, but also can turn the toxic chemicals into nontoxic H2 O,CO₂ and inorganic substances. In addition, it solves the problem of the evolution of bacteria resistance.There are still existing problems in wide bandgap semiconductors for photocatalytic sterilization application that the visible light utilization rate is low and the carrier recombination velocity is fast, which will seriously affect the efficiency of photocatalytic sterilization in practical application. In this thesis, a more in-depth study on the photocatalytic application of TiO₂ is selected combining with a narrow band gap and a strong conductive ability of In₂O₃. Eventually, TiO₂/In₂O₃ heterogeneous structure is formed for sterilization experiment. On the one hand, the formation of built-in electric field of heterojunction can improve the separating results of the photo-induced carriers; on the other hand, the addition of In₂O₃ can expand the absorption spectrum of TiO₂. In the meanwhile, the comparative experiment is conducted on TiO₂ films and TiO₂-In₂O₃ composite films which are prepared by sol-gel method. The crystal structure, morphology, and absorption property of these films were studied by XRD, SEM, AFM and UV-visible spectra.TiO₂ monolayer films, TiO₂-In₂O₃ composite films and TiO₂/In₂O₃ heterogeneous films annealed at 400?, 450?, 500? and 550? are selected to conduct the sterilization experiments. Under the same experimental conditions, the performance of multiple groups of sterilization is tested. From the test results, with the increase of annealing temperature, the sterilizing effect of these three kinds of films will be increased. Moreover, the TiO₂/In₂O₃ films show the stronger, faster and more thorough sterilization ability than the others.