TiO2/SiO2 纳米粒子气相光催化降解甲苯的研究

以TiO₂/SiO₂纳米粒子为催化剂， 研究了甲苯的初始浓度、 氧气和水蒸气含量及光强等对其光催化氧化降解的影响. 甲苯初始反应速率随其初始浓度的增加而增大， 最终趋于稳定. 氧气含量增加， 甲苯反应速率增大， 氧气含量增至18％时， 抑制反应速率增加. 水分子含量对甲苯反应速率的影响也有最佳值0.2％（体积比）. 甲苯的反应速率随光强增加而增大， 在3 mW/cm²时， 反应速率趋于定值. 采用Langmuir-Hinshelwood动力学模型得到甲苯光催化降解的反应速率常数和吸附常数， 并通过FI-RT和GC-MS初步确定了反应产物.

Photocatalytic Degradation of Gas-phase Toluene over Nano-TiO2/SiO2

The photocatalytic oxidation of toluene over {TiO_2/SiO_2} in the gas-phase was investigated. The feasibility studies involved the effects of initial concentration of reactant, oxygen content, water vapor content and light intensity on the photocatalytic reaction. The photocatalytic degradation rate increased with increasing the initial concentration of toluene, but maintained almost a constant beyond a certain concentration of it. It matched well with the Langmuir-Hinshelwood kinetic model. The reaction rate increased with increasing oxygen content, but the oxygen content was higher than 18%(volume percentage), the reaction rate was restrained. For the influence of water vapor in the gas-phase on the photocatalytic degradation rate of toluene, there was an optimum concentration of water vapor (0.2%). The photocatalytic degradation rate increased with light intensity but the rate leveled off to a constant when the light intensity rose to 3 mW/cm2. The photocatalytic degradation rate constant and the adsorption constant of toluene were obtained by means of the Langmuir-Hinshelwood model, and the reaction products were also identified by FI-RT and GC-MS.