title: Visible light photocatalytic activity of aromatic polyamide dendrimer/TiO2 composites functionalized with spirolactam-based molecular switch.
abstract: A novel aromatic polyamide dendrimer-TiO2 hybrid photocatalyst functionalized with spirolactam-based molecular switch (RG-TiO2) was synthesized. The materials were characterized by FT-IR and scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and UV-vis diffuse reflectance spectroscopy, in comparison with reference materials (plain TiO2). The photocatalytic activity and photostability of RG-TiO2 were investigated based on the degradation of phenol under visible light irradiation. The results showed that the RG-TiO2 hybrid photocatalyst enhanced photocatalytic efficiency of photodegradation of phenol compared with the as-prepared plain TiO2 under visible light irradiation. More significantly, when the RG-TiO2 was acidified to pH 3, the RG-TiO2 was readily transformed from spirolactam form (OFF) to the ring-opened amide form (ON). And the photocatalytic stability of ring-opened RG-TiO2 (switch off form) was much lower than that of ring-closed RG-TiO2 (switch on form). The novel fabrication method of the TiO2 photocatalyst provides a valuable way for developing highly efficient and controllable photocatalysts by molecular switch.
authors.affiliation: State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, PR China. leiyonglin@163.com
authors.forename: Yonglin
authors.initials: Y
authors.lastname: Lei
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Lei
authors.forename: Jichuan
authors.initials: J
authors.lastname: Huo
keywords: Aromatic polyamide dendrimer; Photocatalyst; Spirolactam-based molecular switch; TiO(2); Visible irradiation