Preparation And Characterization Of Nanocomposites CoTCPP/TiO₂, And Application In Visible Light Induced

The nanocomposites TiO₂ materials are widely used in solar cells, biomedicine, environmental engineering and many other areas due to the unique photocatalytic oxidation ability, strong photocatalytic efficiency, chemical stability and low cost. But in the current, there are few reports on the study of photoinduced electron transfer of nano-TiO₂. Furthermore, the quick recombination of electrons and holes leads to quenching phenomenon significantly so the efficiency of the photocatalysis remains to be further improved. To solve the problems mentioned above, this work concentrates on the synthesis of a fine nano-TiO₂-porphyrin complex to reduce the electron-hole pair recombination rate, and to study its optical switching behavior, the main results of this thesis are as follows:1. A novel nano-material TiO₂/CoTCPP was synthesized, UV-visble absorption spectra(UV), Fluorescence spectra, Thermal Analysis(TGA), Transmission electron microscopy (TEM), scanning electron microscopy (SEM), IR, Phase and grain size analysis of materials(XRD) were used to characterize the morphology and structure of the composite, and the optical properties of the material was investigated. Results show that the composite has better thermal stability and excellent photoelectric conversion performance.2. The photoinduced electron transfer of the composite was studied by the combination of scanning electrochemical microscopy and photoelectronchemical technology. By building a new model of SECM-visible light spectrometer, the influence of light on the electron transfer was studied and be used to simulate the photoelectric conversion and electron transfer in photosynthesis.3. The functional TiO₂ nanoparticles are applied to photoelectrochemical measurement. By using HQ as a model, a methodology for sensitive photoelectrochemical biosensing at low potential was thus developed. The proposed photoelectrochemical method could detect HQ ranging from 0.01 to 0.75 mmol/L with a detection limit of 0.006 mmol/L at a signal-to-noise ratio of 3(S/N=3). The photoelectrochemical method has low applied potential, rapid response, wide linear range, and good reproducibility and repeatability. 4. The properties of electron transfer on interface and its mechanism from a new perspective will be illumined by constructing a highly ordered monolayer system (Nano-Au-Porphyrin modified ITO electrode) and having application in chemically modified electrode surface to study electron transfer process. Based on this, in the present of photoinduction, the photoelectric conversion and electron transfer process were systematically studied on simulated biofilm interface (solid/liquid), in which porphyrin and benzoquinone were used as the matching material.