Chemical bonding character and physicochemical properties of mesoporous zinc oxide-layered titanate nanocomposites
Chemical bonding character and physicochemical properties of mesoporous zinc oxide-layered titanate nanocomposites
复制标题
DOI：
10.1021/jp0662552
复制
发表时间：
2007-02-01
影响因子：
3.7
通讯作者：
Choy, Jin-Ho
中科院分区：
文献类型：
--
作者：
Kim, Tae Woo;Hwang, Seong-Ju;Choy, Jin-Ho
我们研究了通过剥离-重堆积途径合成的介孔氧化锌层状钛酸盐纳米复合材料的化学键合特性和物理化学性质。根据我们使用X射线衍射、高分辨率透射电子显微镜和N-2吸附-解吸等温线测量的分析，纳米晶氧化锌不仅稳定在主体钛酸盐的层间空间中，而且稳定在由微晶的卡屋式堆叠形成的纳米复合材料的介孔中。 Ti K 和 Zn K 边缘的 X 射线吸收光谱分析清楚地表明，纳米晶氧化锌以纤锌矿型结构结晶，并且主体钛酸盐的纤铁矿结构在杂化和后煅烧后保持不变。与氧化锌纳米粒子杂化后，层状钛酸酯的光催化活性相对于苯酚和二氯乙酸盐的氧化光降解得到增强。但更重要的是，通过与层状钛酸盐杂化，客体氧化锌对抗酸性腐蚀的化学稳定性大大提高。在这方面，本发明的杂化技术使得即使在腐蚀性环境中也能够应用化学不稳定的窄结构氧化锌。
We have investigated the chemical bonding character and physicochemical properties of mesoporous zinc oxide-layered titanate nanocomposites synthesized by an exfoliation-restacking route. According to our analyses using X-ray diffraction, high resolution transmission electron microscopy, and N-2 adsorption-desorption isotherm measurements, nanocrystalline zinc oxides are stabilized not only in the interlayer space of the host titanate but also in the mesopores of the nanocomposites formed by the house-of-card type stacking of the crystallites. X-ray absorption spectroscopic analyses at Ti K- and Zn K-edges clearly demonstrate that nanocrystalline zinc oxides crystallized with a Wurzite type structure, and the lepidocrocite structure of the host titanate remains unchanged after hybridization and postcalcination. Upon hybridization with zinc oxide nanoparticles, the photocatalytic activity of layered titanate is enhanced with respect to the oxidative photodegradation of phenol and dichloroacetate. But of greater importance is that the chemical stability of guest zinc oxide against acidic corrosion is greatly improved by hybridization with layered titanate. In this regard, the present hybridization technique enables the application of chemically unstable narrostructured zinc oxides even in corrosive environments.