Basic Study On Photocatalytic Degradation Of Car TVOC By The TiO₂Based Nanotube Arrays

As is known to us all, automotive interior materials release lots of volatile organic compounds(VOC), which harm human health seriously. This paper outlines the TVOC emission from interior materials and the wide application of photocatalytic purification technology in the environment field. By setting up TVOC emission measuring bench and photocatalytic TVOC degradation bench, We studied the TVOC emission characteristic from interior materials and the preparation process of TiO2-based nanotube arrays, and established the mathematical medol of TVOC photocatalytic degradation on TiO2-based nanotube arrays, which reveals the quantitative relationship between the TVOC degradation rate and the photocatalytic process parameter.The results reveal that the TVOC release coefficient increases with increasing temperature and humidity and the three pretreatment methods can effectively remove TVOC in mats, in which washing and dryiny method works best, and the higher water temperature is beneficial to the release of TVOC.TiO2nanotubes arrays(TNAs) were prepared by anodic oxidation and were characterized by SEM, the results have showed that the nanotubes morphology is related to the solvent; ethylene glycol which is of moderate viscosity and conductivity is suitable to be solvent for preparation of TNAs; the anode area is too large or too small to generate nanotubes. Better morphology TNAs have been prepared with the ratio of anode area to electrolyte volume being0.05cm-1and the appropriate electrode gap.On the basic of mass transfer theory of TVOC molecular in nanotube, The TVOC photocatlytic degration rate model in TNAs has been proposed and model parameter has been estimated. And model values were compared with the experimental data, the error was less than20%. The model shows there is an optimal diameter for the maximum degradation rate.The preparation processes of Fe2O3/TNAs and Cu2O/TNAs composite nanotubes with better photocatalytic activity have been studied by experiment. The paper analyses the morphology, the optical response of Fe2O3/TNAs and Cu2O/TNAs and TVOC degradation effects on them, the results show the TVOC degradation effect on Cu2O/TNAs is better than on Fe2O3/TNAs, which are related to the Fe2O3and Cu2O amount, and the TVOC degradation on Fe2O3/TNAs and Cu2O/TNAs meets first-order kinetics.The effects of Cu content, temperature, humidity, oxygen content on photocatalytic degradation of TVOC were studied, and the kinetic model has been established. And model values were compared with the experimental data, the error was less than20%. The model shows the TVOC degradation effect is best when the doped-copper content, oxygen content and humidity is31.37%,36.92%and33.71%,respectively.