低温下TiO2光催化降解三甲胺气体

Study on photocatalytic degradation of trimethylamine with TiO_2 under the low temperature

为探讨低温下紫外光催化Ti O_2降解三甲胺气体的效果,以紫外灯为光源,研究了Ti O_2处理、紫外光处理、紫外光辐照催化Ti O_2处理3种方法降解三甲胺气体的效果,并探讨了三甲胺初始浓度和紫外光辐照强度对三甲胺光催化降解效果的影响。结果表明:Ti O_2光催化降解三甲胺效果显著,降解过程中ln(C_0/C_t)与时间t呈良好的线性关系,三甲胺的光催化降解遵循一级反应动力学过程;在光强为147μW/cm^2的条件下,当三甲胺的初始质量浓度在3~12 mg/m^3内时,随三甲胺初始浓度C_0的增加,其降解率逐渐降低,反应速率常数K也逐渐减小,K与C_0的线性关系为K=-0.002 4C_0+0.050 2(R^2=0.997 0);在三甲胺初始浓度为12 mg/m^3的条件下,当光强在28~170μW/cm^2内时,随紫外光辐照强度I的增加,三甲胺的降解率逐渐增大,反应速率常数K也逐渐增大,K与I的线性关系为K=0.005 0ln(I)-0.003 3(R^2=0.993 3)。

To study the effect of photocatalytic degradation of trimethylamine with TiO2 under the low temperature,UV lamp was used as light source,and the effects of TiO2,UV light and TiO2 catalyzed by UV light on the degradation of trimethylamine were studied in low temperature. In addition,the effects of the initial concentration of trimethylamine and the intensity of UV light on the photocatalytic degradation were also studied. It was showed that the photocatalytic degradation of trimethylamine was effective,and a good linear relation between ln（ C0/ C_t） and t was presented in the process of photocatalytic degradation. The process of photocatalytic degradation of trimethylamine followed the first- order kinetics. When the UV light intensity was 147 μW / cm^2 and the initial concentration was from 3mg / m^3 to 12 mg / m^3,the rate of degradation and reaction rate constants both decreased with the increase of the initial concentration,the relationship between K and C0 was K =- 0. 002 4C0＋ 0. 050 2（ R^2= 0. 997 0）. When the initial concentration was 12 mg / m^3 and the UV light intensity was from 28 μW / cm^2 to 170 μW / cm^2,the rate of degradation and reaction＇s rate constant were both increased with the increasing of UV light intensity,and the relationship between K and I was K = 0. 005 0 ln（ I）- 0. 003 3（ R^2= 0. 993 3）.