Key Laboratory of Microsystems and Micronanostructures Manufacturing (Ministry of Education), Harbin Institute of Technology, Harbin 150080, China.
Nanoscale. 2013 Sep 7;5(17):8184-91. doi: 10.1039/c3nr02352d.
Mesoporous anatase TiO2 spheres with tunable sizes ranging from 400 nm to 3 μm were synthesized using an original so-called "water-controlled solvothemal release process". In this method, the well-known esterification reaction between ethanol and acetic acid was creatively employed to generate water gradually during a solvothermal process. Thereafter, the slowly released water molecules functioned as nucleation centers for completing the hydrolysis of titanium tetraisopropoxide to produce homogenous mesoporous TiO2 spheres. In reality, these samples consisted of densely packed nanoparticles that formed spherical secondary particles with interparticle pores. Research has demonstrated that the diameter of the TiO2 spheres can be easily tuned by controlling the concentration of the Ti source in the starting solution. Regardless of their diameter, all of these TiO2 spheres exhibited a high specific surface area (above 150 m(2) g(-1)) originating largely from the contribution of mesopores. On the merits of their porous structure and related high specific surface area, the mesoporous TiO2 spheres showed a higher photocatalytic activity than P25 for the oxidative photo-destruction of NOx gas.
采用原创的所谓“水控溶剂热释放法”，成功合成了尺寸可调（从 400nm 至 3μm）的介孔锐钛矿 TiO2 球。在该方法中，巧妙地利用乙醇和乙酸之间的酯化反应在溶剂热过程中逐渐生成水。此后，缓慢释放的水分子充当成核中心，完成钛四异丙醇酯的水解，生成均匀的介孔 TiO2 球。实际上，这些样品由紧密堆积的纳米颗粒组成，这些纳米颗粒形成具有颗粒间孔的球形二次颗粒。研究表明，通过控制起始溶液中 Ti 源的浓度，可以轻松调节 TiO2 球的直径。无论直径如何，所有这些 TiO2 球都表现出高比表面积（高于 150m2/g），主要归因于介孔的贡献。由于其多孔结构和相关的高比表面积，介孔 TiO2 球在氧化光降解 NOx 气体方面表现出比 P25 更高的光催化活性。
