摘要
通过原位红外光谱技术研究了可见光下甲苯在CdS-TiO2/MWCNTs(多壁碳纳米管)和CdS-TiO2光催化剂表面的吸附、光催化降解过程,并考察了水汽对光催化反应的影响.结果表明,在吸附过程中甲苯在CdS-TiO2和CdS-TiO2/MWCNTs光催化剂表面就能被氧化成苯甲醛、苯甲酸等中间产物,水汽的存在有利于提高光催化剂的活性,促进甲苯氧化成CO2.光催化过程中苯甲酸的深度氧化是整个反应的速率控制步骤,苯甲醛、苯甲酸等中间产物的积累是导致光催化剂失活的原因之一.在本实验条件下,甲苯在CdS-TiO2和CdS-TiO2/MWCNTs表面的光催化降解过程符合一级反应动力学方程.
Under visible light irradiation,in situ infrared spectroscopy was used to analyze the adsorption and photocatalytic degradation of gas-phase toluene over CdS-TiO2 and CdS-TiO2/MWCNTs.The effect of humidity on the photocatalytic reaction was also discussed.Our research results indicated that benzaldhyde and benzoic acid were identified on the surface of CdS-TiO2 and CdS-TiO2/MWCNTs during the adsorption process.Humidity plays an important role in the photocatalytic oxidation toluene to CO2.The deep oxidation of benzoic acid may turn to be the rate-controlling factor of the photocatalytic oxidation of toluene.The accumulation of benzaldhyde and benzoic acid was one of the reasons for the photocatalysts deactivation.The photocatalytic degradation of toluene followed the first-order chemical kinetics equation under our experimental conditions.
出处
《环境科学学报》
CAS
CSCD
北大核心
2011年第9期1881-1886,共6页
Acta Scientiae Circumstantiae
基金
国家高技术研究发展计划(863)项目(No.2006AA06A310)
广东省科技计划项目(No.2008B050100007
2009B050900005)~~
