Mahy Julien G, Cerfontaine Vincent, Poelman Dirk, Devred François, Gaigneaux Eric M, Heinrichs Benoît, Lambert Stéphanie D
Department of Chemical Engineering-Nanomaterials, Catalysis & Electrochemistry, University of Liège, B6a, Quartier Agora, Allée du six Août 11, 4000 Liège, Belgium.
LumiLab, Department of Solid State Sciences, Ghent University, 9000 Gent, Belgium.
Materials (Basel). 2018 Apr 10;11(4):584. doi: 10.3390/ma11040584.
In this paper, TiO₂ prepared with an aqueous sol-gel synthesis by peptization process is doped with nitrogen precursor to extend its activity towards the visible region. Three N-precursors are used: urea, ethylenediamine and triethylamine. Different molar N/Ti ratios are tested and the synthesis is adapted for each dopant. For urea- and trimethylamine-doped samples, anatase-brookite TiO₂ nanoparticles of 6-8 nm are formed, with a specific surface area between 200 and 275 m²·g. In ethylenediamine-doped samples, the formation of rutile phase is observed, and TiO₂ nanoparticles of 6-8 nm with a specific surface area between 185 and 240 m²·g are obtained. X-ray photoelectron spectroscopy (XPS) and diffuse reflectance measurements show the incorporation of nitrogen in TiO₂ materials through Ti-O-N bonds allowing light absorption in the visible region. Photocatalytic tests on the remediation of water polluted with -nitrophenol show a marked improvement for all doped catalysts under visible light. The optimum doping, taking into account cost, activity and ease of synthesis, is up-scaled to a volume of 5 L and compared to commercial Degussa P25 material. This up-scaled sample shows similar properties compared to the lab-scale sample, i.e., a photoactivity 4 times higher than commercial P25.
在本文中，通过胶溶法采用水溶胶 - 凝胶合成法制备的TiO₂用氮前驱体进行掺杂，以扩展其在可见光区域的活性。使用了三种氮前驱体：尿素、乙二胺和三乙胺。测试了不同的氮/钛摩尔比，并针对每种掺杂剂调整了合成方法。对于尿素和三甲胺掺杂的样品，形成了6 - 8纳米的锐钛矿 - 板钛矿TiO₂纳米颗粒，比表面积在200至275 m²·g之间。在乙二胺掺杂的样品中，观察到金红石相的形成，获得了比表面积在185至240 m²·g之间的6 - 8纳米TiO₂纳米颗粒。X射线光电子能谱（XPS）和漫反射测量表明，氮通过Ti - O - N键掺入TiO₂材料中，从而实现可见光吸收。对用对硝基苯酚污染的水进行光催化修复测试表明，在可见光下所有掺杂催化剂的性能都有显著改善。考虑到成本、活性和合成的难易程度，将最佳掺杂放大到5 L的体积，并与商业德固赛P25材料进行比较。这种放大后的样品与实验室规模的样品具有相似的性能，即光活性比商业P25高4倍。
