文章基本信息

标题：Theoretical investigation on the adsorption configuration and •OH-initiated photocatalytic degradation mechanism of typical atmospheric VOCs styrene onto (TiO2)n clusters
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作者：Honghong Wang ; Yuemeng Ji ; Jiangyao Chen 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2015
卷号：5
期号：1
DOI：10.1038/srep15059
语种：English
出版社：Springer Nature
摘要：In this study, the adsorption mechanism and hydroxyl radical (^•OH)-initiated photocatalytic degradation mechanism of styrene onto different (TiO₂)_n clusters were investigated using density functional theory. Styrene, a typical model atmospheric volatile organic compound (VOC), was found to be readily adsorbed onto (TiO₂)_n clusters through its vinyl group with strong chemisorption. This suggests that (TiO₂)_n clusters (sub 1 nm) are able to effectively adsorb and trap styrene. Adsorbed styrene is then easily attacked by ^•OH to form a series of vinyl-OH-adducts. Conversely, phenyl-OH-adducts and H-abstraction products are very difficult to form in this system. Kinetics calculations using canonical variational transition state theory show that temperature has little effect on the rate constants during photocatalytic degradation process. The presence of TiO₂ does not change the degradation mechanism of styrene, but can accelerate its photocatalyic degradation rate, and the rate will increase as TiO₂ cluster size increases; as such, the TiO₂ nano-clusters catalyst should have the photocatalytic ability to effectively degrade styrene. This theory-based study offers insights into the catalytic effect of TiO₂ catalyst and the photocatalytic degradation mechanism of benzene series air pollutants at the molecular level.