水基TiO_2涂覆液降解汽车尾气效果评价研究

为了定量评价分析Ti O_2添加量对汽车尾气中NO、HC、CO三种气体降解效果、涂覆液对沥青混合料抗滑性能的影响以及确定经济合理的添加量,将Ti O_2光触媒材料添加到水溶液中制备涂覆液并涂覆到AC沥青混合料表面用以开展相关研究.研究表明:即时降解率可作为Ti O_2光触媒材料对尾气中的NO等气体降解效果的评价指标;Ti O_2光触媒材料添加比例占涂覆液含量的2%时最为经济合理;路面的抗滑性能会因涂覆水基Ti O_2而降低,但仍满足相关规范要求.

水基纳米TiO_2路径制备有序介孔TiO_2-SiO_2及其可见光催化性能

在多巴胺修饰的水基TiO_2纳米微粒(TiO_2NPs)悬浮液中,以正硅酸乙酯为硅源,十六烷基三甲基溴化铵为模板剂,分别采用碱性水热方法或酸性溶胶-凝胶方法,制备了有序介孔TiO_2-SiO_2(TiO_2NPs/MCM-41或TiO_2NPs/SBA-3)。采用XRD、TEM、ICP和N2吸附-脱附实验对样品进行表征。结果表明,制备的介孔TiO_2-SiO_2在TiO_2高负载质量分数(23.98%TiO_2NPs/MCM-41、17.27%TiO_2NPs/SBA-3)时,仍能保持长程有序的介孔氧化硅结构。TiO_2NPs随机地嵌入在有序介孔氧化硅孔道所组成的网络结构中。在可见光下催化甲基橙降解反应中,反应时间120 min时,在P25上甲基橙相对浓度降为57%,在TiO_2NPs/MCM-41上降为33%,而在TiO_2NPs/SBA-3上降为5.7%。

Kinetics of Photocatalytic Degradation of Methylene Blue over TiO_2 Particles in Aqueous Suspensions

The kinetics of photodegradation of methylene blue over UV light illuminated titania particles in aqueous suspensions has been studied with different initial methylene blue concentrations and TiO2 particle sizes. The degradation rate increases with the decrease of initial concentration and particle size. A quasi-experienced model for photodegradation rate is derived based mainly on the coinstantaneous effects of different initial concentrations and particle sizes. The mathematical relationships of model parameters with initial concentration and particle size are given. The model results of the photodegradation rate of methylene blue are coincident with the experimental data.