title: In situ growth of TiO2 in interlayers of expanded graphite for the fabrication of TiO2-graphene with enhanced photocatalytic activity.
abstract: We present a facile route for the preparation of TiO(2)-graphene composites by in situ growth of TiO(2) in the interlayer of inexpensive expanded graphite (EG) under solvothermal conditions. A vacuum-assisted technique combined with the use of a surfactant (cetyltrimethylammonium bromide) plays a key role in the fabrication of such composites. Firstly, the vacuum environment promotes full infusion of the initial solution containing Ti(OBu)(4) and the surfactant into the interlayers of EG. Subsequently, numerous TiO(2) nanoparticles uniformly grow in situ in the interlayers with the help of the surfactant, which facilitates the exfoliation of EG under the solvothermal conditions in ethanol, eventually forming TiO(2)-graphene composites. The as-prepared samples have been characterized by Raman and FTIR spectroscopies, SEM, TEM, AFM, and thermogravimetic analysis. It is shown that a large number of TiO(2) nanoparticles homogeneously cover the surface of high-quality graphene sheets. The graphene exhibits a multi-layered structure (5-7 layers). Notably, the TiO(2)-graphene composite (only 30 wt % of which is TiO(2)) synthesized by subsequent thermal treatment at high temperature under nitrogen shows high photocatalytic activity in the degradation of phenol under visible and UV lights in comparison with bare Degussa P25. The enhanced photocatalytic performance is attributed to increased charge separation, improved light absorbance and light absorption width, and high adsorptivity for pollutants.
authors.affiliation: Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, Heilongjiang University, Harbin 150080, P. R. China.
authors.forename: Baojiang
authors.initials: B
authors.lastname: Jiang
authors.forename: Chungui
authors.initials: C
authors.lastname: Tian
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Xie
authors.forename: Qingjiang
authors.initials: Q
authors.lastname: Pan
authors.forename: Zhiyu
authors.initials: Z
authors.lastname: Ren
authors.forename: Youzhen
authors.initials: Y
authors.lastname: Dong
authors.forename: Dan
authors.initials: D
authors.lastname: Fu
authors.forename: Jiale
authors.initials: J
authors.lastname: Han
authors.forename: Honggang
authors.initials: H
authors.lastname: Fu
mesh_terms: D002384:Catalysis; D006108:Graphite / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D010777:Photochemistry; D013501:Surface-Active Agents; D014025:Titanium / Q000737:chemistry*; D014618:Vacuum
chemical_list: D013501:Surface-Active Agents; C009495:titanium dioxide; D006108:Graphite; D014025:Titanium