An aspirated in-syringe device fixed with Ionic liquid and β-cyclodextrin functionalized CNTs/TiO2 for rapid adsorption and visible light-induced photocatalytic activity

In this paper, the ionic liquid (IL), 1-octyl-3-methylimidazolium hexafluorophosphate ([Omim][PF6]) was employed to synthesize β-cyclodextrin (β-CD) functionalized carbon nanotubes/TiO2 (IL-CD-CNTs/TiO2) nanocomposite through a one-pot solvothermal process. The as-prepared product was characterized by SEM, TEM, XRD, TG, FT-IR, EIS and so forth. Coupled with an aspirated in-syringe device, IL-CD-CNTs/TiO2 could achieve the rapid removal of water contaminants with 8 min. In addition to the excellent adsorption capacity, this dual-functional photocatalyst also showed the enhanced photocatalytic activity under visible light with a degradatioin rate of 97% within 180 min. The photocatalytic mechanism based on the formation of inclusion complex, density functional theory and electronic structure of IL-CD-CNTs/TiO2 was discussed in detail. The IL not only served as the reaction medium but also played a crucial role in improving adsorption capacity and photocatalytic activity. By acting as a strong donating electron character, IL could promote the efficient charge-transfer, inhibiting the recombination of photogenerated electron-hole pairs. The as-prepared photocatalyst capable of rapid adsorption and photodegradation would meet the requirements of practical application and suggest a promising direction for waste water treatment.