Study On Degradation Of Indoor Hazardous Gases By Modified Titanium Dioxide

In this thesis, gas chromatography,electrochemical testing methods and oscillations elution were used, to explore the relation between degradation of the effect of gas xylene, sterilization effect and their electrochemical signals of TiO2 spray added with different sensitizers, different electric charge and coupling agents. Found by gas-xylene degradation test:sensitizer would contribute to the degradation effect of gas xylene, sensitization agent B on the degradation of titanium dioxide can improve the efficiency best, which was consistent with the result ofⅠ-Ⅴcurve of the electrochemical test results. The energy level of sensitizing agent B and titanium dioxide can be matched best. TEM images reveal that the size of titanium dioxide particles in the spray was nano-level and the particles can reach nanometer dispersion, because when the size of titanium dioxide reaches nano-level, the particles will possess the quantum size effect, small size effect etc, these effects will ensure the titanium dioxide to produce more excited carriers, allowing more active groups created to enhance the degradation efficiency of titanium dioxide spray. When the size of titanium dioxide particles reaches the nanoscale, the time of the excited electrons migrating from the surface to the body was far less than the electron-hole recombination time, and the electron-hole composite probability can be decreased, therefore improving the efficiency of xylene degradation. By cyclic voltammetry test it can be seen that there were active groups created such as·OH,O2-·. By comparing the activation energy of the·OH, the hole and the bond energy of organic matter, the energy of·OH and hole is higher than the energy bond of organic matter. Through short-term effects of degradation data, the degradation mechanism of decomposition of organic harmful gases by nano-TiO2 was found out. Under the stimulation of the light, titanium dioxide can generate active groups, and organic harmful gas can be decomposed into non-toxic molecules, such as CO2, H2O and other small molecules.