Elucidation of mesopore-organic molecules interactions in mesoporous TiO2 photocatalysts to improve photocatalytic activity

作者：Lin, Xuan Hao; Wu, Ye; Xiang, Jiao; He, Da; Li, Sam Fong Yau^*

来源：Applied Catalysis B: Environmental , 2016, 199: 64-74.

DOI：10.1016/j.apcatb.2016.06.023

• Mesoporous
• Mesopore
• TiO2 photocatalyst
• Reverse osmosis concentrate
• Fluorescein

Mesoporous TiO2 photocatalysts were synthesized and characterized by N-2 sorption, XRD, SEM and spectroscopic methods. Formation of the mesopores was attributed to the decomposition of entrapped inorganic ions, which was reported before. Fluorescein molecules were used as model substrate molecules. To investigate interactions between mesopores and fluorescein molecules, a novel two-phase method to differentiate mesopore encapsulation from external surface adsorption was developed in this study, which was also not reported before. This novel two-phase method could be widely applied to study other mesoporous materials. Results showed that fluorescein molecules could enter and exit from the mesopores freely. Fluorescein molecules sealed inside the mesopores could still be photocatalytically degraded to reaction intermediates, i.e. carboxylic acids and final products. Furthermore, it was found that when the mesopores were intentionally sealed by chloroform, photocatalytic activity for the degradation of reverse osmosis concentrate (ROC) decreased. When the mesopores were open the dissolved organic compounds (DOC) in ROC could go into the mesopores and,their photocatalytic degradation products could also come out from the mesopores. Correlation of photocatalytic activity to surface area and mesopore volume was investigated. Formation mechanism of mesopores was elucidated. Interactions between the mesopores and fluorescein molecules are also described.

• 出版日期2016-12-15
• 单位北京大学深圳研究生院; 北京大学