Li Hongliang, Liu Hui, Fu Aiping, Wu Guanglei, Xu Man, Pang Guangsheng, Guo Peizhi, Liu Jingquan, Zhao Xiu Song
Institute of Materials for Energy and Environment, Qingdao University, Qingdao 266071, China.
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.
Materials (Basel). 2016 Oct 19;9(10):849. doi: 10.3390/ma9100849.
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.
基于溶胶-凝胶合成法并结合煅烧工艺，制备了三种具有不同氮掺杂含量、表面积和孔径分布的氮掺杂介孔TiO₂空心球。三聚氰胺甲醛（MF）微球被用作牺牲模板，十六烷基三甲基溴化铵（CTAB）或聚乙烯吡咯烷酮（PVP）被选作造孔剂。通过将TiO₂前驱体的体积浓度从1 vol% 变化到3 vol%，制备了直径为1.2 - 1.6 μm的二氧化钛包覆MF的核壳中间球。通过在空气中于500 °C煅烧核壳复合球3 h，在MF模板和CTAB或PVP造孔表面活性剂分解时发生原位氮掺杂过程。获得了尺寸在0.4 - 1.2 μm范围内且壳厚度为40 - 110 nm的氮掺杂介孔TiO₂空心球。基于傅里叶变换红外（FTIR）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、热重分析（TGA）、氮吸附-脱附以及紫外-可见分光光度法等技术，对不同条件下得到的介孔TiO₂空心球的组成和氮掺杂含量、热稳定性、形态、表面积和孔径分布、壁厚、光催化活性以及光学性质进行了研究和比较。基于这些空心球形TiO₂基体的组成分析、结构表征和光学性质研究，探讨了TiO₂空心球的粒径、氮掺杂、多孔和空心特性对其光催化活性和光学性质的影响。
