TiO2多孔性薄膜光催化降解低浓度甲醛

采用不锈钢丝网负载TiO₂多孔性薄膜光催化剂,在间歇式循环光催化反应系统中研究了气相中低浓度甲醛的光催化降解,考察了催化剂载体、催化剂镀膜次数、甲醛初始浓度和光源等因素的影响,并对光催化剂的稳定性进行了研究.结果表明,甲醛降解率随着丝网目数的增加而增大;丝网使用数量的增多会提高甲醛降解率,但其影响随着丝网数量的增多而逐渐减弱;催化剂镀膜次数从1次增加到6次时,光催化剂的活性先上升后下降;当甲醛初始浓度在1.34～10.72mg/m³范围内增加时,甲醛的浓度变化值相应明显增大,但甲醛降解率先升高继而下降;光源采用杀菌灯时甲醛降解率比黑光灯时约高出19.0%,增大光强度使甲醛降解率提高了20.5%;光催化剂连续使用4次后,仍保持较高的催化活性.

Photocatalytic Degradation of Low Level Formaldehyde on TiO2 Porous Film

Photocatalytic degradation of low level formaldehyde in the gas phase was studied in a intermittent recirculation photocatalytic reaction system with TiO2 porous film photocatalyst coated on stainless steel mesh. The effects of carrier of the photocatalyst, coating cycle of the photocatalyst, the initial concentration of formaldehyde and the illumination source were investigated respectively. The study of the aging stability of the photocatalyst was carried out as well. Results show that the degradation efficiency of formaldehyde increased with the increase of mesh number. The degradation efficiency also increased with the increase of carrier number, but the influence of carrier number on the degradation efficiexcy was gradually weakened with increasing carrier number. The activity of the photocatalyst firstly increased and then decreased when coating cycle increased from 1 cycle to 6 cycles. When initial concentration was in the range of 1.34 - 10.72 mg/m3, the change of formaldehyde concentration markedly increased with the increase of initial concentration, but the degradation efficiency increased and subsequently decreased with increasing initial concentration. The degradation efficiency with germicidal light was approximately 19.0% higher than that with black light holding same power, and the enhancement in light intensity could approximately increase the degradation efficiency by 20.5%. Finally, the experiment on the longevity of the photocatalyst indicated that the photocatalyst had the good photocatalytic activity after being used for 4 cycles.