Research On The Synthesis And Photocatalytic Performance Of Dye Sensitized Nano Zinc Oxide Based/Titanium Dioxide Based Composite Materials

Flower-like ZnO particles were fabricated via hydrothermal methodkept at160°C, selecting zinc acetate as zinc source, sodium hydroxide asalkali source and cetyltrimethyl ammonium bromide (CTAB) assurfactant. Meanwhile, spherical ZnO particles were also prepared byhydrothermal method kept at180°C choosing zinc acetate as zinc source,glucose as template. Compared with the commercial ZnO, the ZnOparticles we obtained exhibited excellent photocatalytic performance inthe process of MO degradation under UV-light irradiation, and sphericalZnO own the optimal activity which due to its larger specific area and theexistence of more oxygen vacancies and Zn sites.Indole squarine dye sensitized ZnO(ISQ/ZnO) nanocompositecatalysts were fabricated via two sensitization processes includinghydrothermal method and ultrasonic method. Experimental resultsdemonstrated that the light response range was extended from UV-light tovisible-light region. The separation efficiency of the photogeneratedelectron-hole pairs was remarkably enhanced, which reinforced theutilization and capture capabilities of visible-light. Photo-degradationexperiment indicated that ISQ/ZnO synthesized via ultrasonicsensitization method possess the optimal photocatalytic activity.TiO2microspheres were fabricated via improved PICA method,which is choosing titanium tetrabutoxide as titanium source, ureaformaldehyde as aggregate, and TiO2microspheres were obtained afterhigh-heat treatment. Based on BET result, TiO2nanocomposites weobtained hold larger specific surface area and more active sites whichcould induce higher UV photocatalytic activity compared withcommercial and traditional TiO2-P25. ISQ/TiO2nanocompositephotocatalysts with different mass ratio from1:2to1:5were prepared viaultrasonic sensitization method. The optimal dye sensitized amount wasdiscussed after a series of characterizations and photocatalytic experimentwere carried out. And the mass ratio of1:3owned optimal catalyticactivity which ascribed to the sensitization of ISQ dye and charge transfer between photoexcited sensitizer and TiO2. The degradation rate couldreach to70%after5cycle times which demonstrated the compositephotocatalyst possess excellent photostability.Based on the sensitization of indole squarine dye having an effect onnano-materials such as TiO2/ZnO, we continued to investigate thesensitization of different squarine dye structures includingN-methylindole squarine dye (m-ISQ) and chloro-N-methybenzothiazolesquarine dye (c-BSQ). Three different squarine dyes sensitized TiO2nanocomposites were fabricated via ultrasonic sensitization method withoptimal mass ratio. Molecular structure and electron distribution ofHOMO and LUMO orbitals of different dyes were studied. Theconnection type between different dyes and TiO2were discussed throughgaussian geometry optimization. ISQ/TiO2nanocomposites own optimalphotoelectric and optical performance which connected in hydrogenbonding way, and experimental result further confirm stronger chargedelocalization of ISQ/TiO2.