Synthesis and Characterization of N-Doped Porous TiO2 Hollow Spheres and Their Photocatalytic and Optical Properties
Hongliang Li,
Hui Liu,
Aiping Fu,
Guanglei Wu,
Man Xu,
Guangsheng Pang,
Peizhi Guo,
Jingquan Liu,
Xiu Song Zhao
Affiliations
Hongliang Li
Institute of Materials for Energy and Environment, Qingdao University, Qingdao 266071, China
Hui Liu
Institute of Materials for Energy and Environment, Qingdao University, Qingdao 266071, China
Aiping Fu
Laboratory of New Fiber Materials and Modern Textile, Growing Basis for State Key Laboratory, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
Guanglei Wu
Institute of Materials for Energy and Environment, Qingdao University, Qingdao 266071, China
Man Xu
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, China
Guangsheng Pang
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, China
Peizhi Guo
Institute of Materials for Energy and Environment, Qingdao University, Qingdao 266071, China
Jingquan Liu
Laboratory of New Fiber Materials and Modern Textile, Growing Basis for State Key Laboratory, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
Xiu Song Zhao
Institute of Materials for Energy and Environment, Qingdao University, Qingdao 266071, China
Three kinds of N-doped mesoporous TiO2 hollow spheres with different N-doping contents, surface area, and pore size distributions were prepared based on a sol–gel synthesis and combined with a calcination process. Melamine formaldehyde (MF) microspheres have been used as sacrificial template and cetyltrimethyl ammonium bromide (CTAB) or polyvinylpyrrolidone (PVP) was selected as pore-directing agent. Core–shell intermediate spheres of titania-coated MF with diameters of 1.2–1.6 μm were fabricated by varying the volume concentration of TiO2 precursor from 1 to 3 vol %. By calcining the core–shell composite spheres at 500 °C for 3 h in air, an in situ N-doping process occurred upon the decomposition of the MF template and CTAB or PVP pore-directing surfactant. N-doped mesoporous TiO2 hollow spheres with sizes in the range of 0.4–1.2 μm and shell thickness from 40 to 110 nm were obtained. The composition and N-doping content, thermal stability, morphology, surface area and pore size distribution, wall thickness, photocatalytic activities, and optical properties of the mesoporous TiO2 hollow spheres derived from different conditions were investigated and compared based on Fourier-transformation infrared (FTIR), SEM, TEM, thermogravimetric analysis (TGA), nitrogen adsorption–desorption, and UV–vis spectrophotoscopy techniques. The influences of particle size, N-doping, porous, and hollow characteristics of the TiO2 hollow spheres on their photocatalytic activities and optical properties have been studied and discussed based on the composition analysis, structure characterization, and optical property investigation of these hollow spherical TiO2 matrices.
