纳米TiO2光催化降解甲醛的影响因素及动力学研究

本文通过自制光催化反应系统，研究了纳米TiO2光催化降解甲醛的过程，考察环境相对湿度、光照强度、气体流量、甲醛初始浓度等因素对甲醛的气相光催化降解反应的影响，并在此基础上建立了甲醛的光催化降解动力学方程。结果表明：纳米TiO2光催化降解甲醛最佳相对湿度为50%，气体流量为1.2 L/min，光降解率并不会随光照强度的增加无限制地增大，甲醛初始浓度增加将降低光催化氧化降解速率。光催化氧化动力学研究表明该过程可以采用朗格缪尔-欣伍德（Langmuir-Hinshelwood，L-H）动力学方程来表征。其速率方程式为 。

Study on Influencing factors and kinetics of photocatalytic degradation of formaldehyde with nanosized TiO2

With the self-made photocatalytic degradation reaction system, this paper studied the factors influencing the photocatalytic degradation of formaldehyde, by nanosized TiO2, such as the relative humidity, illumination intensity, gas-flow rate and the initial concentration of formaldehyde, and further developed the kinetic model of photocatalytic degradation. The results indicated that the best reaction conditions were as follows: relative humidity 50%, gas-flow rate 1.2 L/min. The photocatalytic degradation rate was not increased unlimitedly with the increase of illumination intensity, but it was reduced with the increment of initial formaldehyde concentration. The kinetic process of photocatalytic degradation of formaldehyde could be characterized by Langmuir-Hinshelwood (L-H) dynamic model. The kinetic model was as following. .