title: One-step hydrothermal synthesis of N-doped TiO2/C nanocomposites with high visible light photocatalytic activity.
abstract: N-doped TiO(2) nanoparticles modified with carbon (denoted N-TiO(2)/C) were successfully prepared by a facile one-pot hydrothermal treatment in the presence of L-lysine, which acts as a ligand to control the nanocrystal growth and as a source of nitrogen and carbon. As-prepared nanocomposites were characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), electron paramagnetic resonance (EPR) spectra, and N(2) adsorption-desorption analysis. The photocatalytic activities of the as-prepared photocatalysts were measured by the degradation of methyl orange (MO) under visible light irradiation at λ≥ 400 nm. The results show that N-TiO(2)/C nanocomposites increase absorption in the visible light region and exhibit a higher photocatalytic activity than pure TiO(2), commercial P25 and previously reported N-doped TiO(2) photocatalysts. We have demonstrated that the nitrogen was doped into the lattice and the carbon species were modified on the surface of the photocatalysts. N-doping narrows the band gap and C-modification enhances the visible light harvesting and accelerates the separation of the photo-generated electrons and holes. As a consequence, the photocatalytic activity is significantly improved. The molar ratio of L-lysine/TiCl(4) and the pH of the hydrothermal reaction solution are important factors affecting the photocatalytic activity of the N-TiO(2)/C; the optimum molar ratio of L-lysine/TiCl(4) is 8 and the optimum pH is ca. 4, at which the catalyst exhibits the highest reactivity. Our findings demonstrate that the as-obtained N-TiO(2)/C photocatalyst is a better and more promising candidate than well studied N-doped TiO(2) alternatives as visible light photocatalysts for potential applications in environmental purification.
authors.affiliation: Division of Nanomaterials and Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China.
authors.forename: Dong-Hong
authors.initials: DH
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Jia
authors.forename: Xi-Lin
authors.initials: XL
authors.lastname: Wu
authors.forename: Li-Qiang
authors.initials: LQ
authors.lastname: Lu
authors.forename: An-Wu
authors.initials: AW
authors.lastname: Xu
mesh_terms: D001391:Azo Compounds / Q000737:chemistry* / Q000528:radiation effects; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D006358:Hot Temperature; D008027:Light; D046911:Macromolecular Substances / Q000737:chemistry / Q000528:radiation effects; D008422:Materials Testing; D008968:Molecular Conformation / Q000528:radiation effects; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects* / Q000648:ultrastructure; D010316:Particle Size; D013499:Surface Properties / Q000528:radiation effects; D014025:Titanium / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D001391:Azo Compounds; D046911:Macromolecular Substances; D014867:Water; C009495:titanium dioxide; C100258:methyl orange; D002244:Carbon; D014025:Titanium