The Research On Photodecomposition Rules Of Chlorine Dioxide Gas

In recent years, the chlorine dioxide gas has attracted more and more attention because of its safety, broad spectrum, and easy to spread in sterilization, disinfection and food preservation. However, the characteristic of easy to decomposition in light, bring a barrier for its application and promotion. For the above reasons, the study on decomposition rules, influence factors, the structure of chlorine oxide and decomposition mechanism of chlorine dioxide gas was carried out. As follows:(1) The study on the decomposition rate of chlorine dioxide gas and its influence factorsChlorine dioxide gas collection and photodecomposition experiment device is self-designed.the study on the decomposition rate of chlorine dioxide gas in different light sources, different temperatures and different initial concentrations, has been done. The degradation rate of Chlorine dioxide gas from fast to slow is the 354nm UV light, natural light, 257nm UV, fluorescence, and the dark room, indicating that the light making a key role on the photodecomposition rate of gradation of Chlorine dioxide gas is the wavelength of UV near the visible and the shorter wavelength of visible light; the concentration of Chlorine dioxide gas was not changed in darkness. In the range of 15 25℃, the temperature had no effect on the degradation rate of the Chlorine dioxide gas.Chlorine dioxide gas in the high concentration (100 200mg / L), the time that the concentration of chlorine dioxide gas is half of the initial concentration is between the 50 60min; when the concentration was low (≤20mg / L), only 10 20min is used to completely decomposition totally.(2) The study on the structure and bonds of chlorine oxideBased on B3LYP/6-311 + G (3df) basis set, the structure, bond, angels, energy and vibration frequency was calculated. The results show that: the chemical bond which links the two momo-chlorine fragments of a di-chlorine oxide or peroxide is formed between their reactive centers and determines the structure; the formation of Cl-Cl bond is not favored.(3) The decomposition products and decomposition mechanism of Chlorine dioxide gasDepend on the experimental analysis and theoretical calculations, found gas in the process of ClO₂ photodecomposition products of Chlorine dioxide, Cl₂ ,Cl₂O₄ and Cl₂O₆, was found, the middle product is Cl₂O₅, and proposed a possible reaction mechanism.