Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences , P.O. Box 1129, Hefei 230031, P.R. China.
ACS Appl Mater Interfaces. 2014 Feb 26;6(4):3008-15. doi: 10.1021/am405607h. Epub 2014 Jan 23.
High yield production of micro/nanostructured nanoparticulate TiO2 microspheres (NTMs) via a facile microwave-assisted hydrothermal approach was investigated. The rapid and uniform microwave heating could reduce the reaction time to 30 min, an order of magnitude shorter than that of conventional hydrothermal methods. The characterization data confirmed that the resultant NTMs were highly uniform in size, having an average diameter of ∼0.5 μm. The obtained NTMs were found to be constructed by well-crystallized anatase phase nanoparticles ranging from 5 to 10 nm that can be readily controlled by the microwave radiation temperature. Nitrogen sorption isotherm analysis revealed that the obtained NTMs possessed abundant mesoporous structures with a high specific surface area of 124 m(2) g(-1). An in situ self-aggregation formation process under controllable pH in presence of urea was proposed. The results obtained from the application of NTMs for simultaneous photocatalytic decontamination of Cr(VI) and methyl orange (MO) demonstrated a strong synergistic effect that dramatically enhanced both Cr(VI) reduction and MO oxidation removal efficiencies. This work not only enriched the synthesis methods of the micro/nanostructured TiO2, but also provided a new means to improve the photocatalytic efficiency via structural-induced synergistic effect, applicable to the other catalysis systems.
通过简便的微波辅助水热法，研究了高产率制备微/纳米结构纳米 TiO2 微球（NTM）的方法。快速且均匀的微波加热可将反应时间缩短至 30 分钟，比传统水热法短一个数量级。表征数据证实，所得的 NTM 在尺寸上非常均匀，平均直径约为 0.5 μm。研究发现，所得的 NTM 由结晶良好的锐钛矿相纳米粒子组成，粒径范围为 5 至 10nm，这可通过微波辐射温度轻松控制。氮气吸附等温线分析表明，所得到的 NTM 具有丰富的中孔结构，比表面积高达 124 m²/g。提出了在尿素存在下可控 pH 下的原位自组装形成过程。将 NTM 应用于同时光催化降解 Cr(VI)和甲基橙（MO）的结果表明，存在强烈的协同效应，可显著提高 Cr(VI)还原和 MO 氧化去除效率。这项工作不仅丰富了微/纳米结构 TiO2 的合成方法，而且还提供了一种通过结构诱导协同效应提高光催化效率的新方法，适用于其他催化体系。
