Zinc titanium glycolate acetate hydrate and its transformation to zinc titanate microrods: synthesis, characterization and photocatalytic properties
Zinc titanium glycolate acetate hydrate and its transformation to zinc titanate microrods: synthesis, characterization and photocatalytic properties
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乙醇酸乙酸锌钛水合物及其向钛酸锌微棒的转化：合成、表征和光催化性能
DOI：
10.1039/c5ra18292a
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发表时间：
2015-01-01
期刊：
影响因子：
3.9
通讯作者：
Zhang, Jiahua
中科院分区：
文献类型：
--
作者：
Pan, Guo-Hui;Hayakawa, Tomokatsu;Zhang, Jiahua
采用室温均相沉淀法在乙二醇溶液中合成了一种杂双金属配合物：水合乙醇酸乙酸锌钛（Zn2Ti3- gah），初步分子式为Zn2Ti3(OCH2CH2O)(4)(OCH2CH2OH)(5)(CH3COO)(3)中心点2HOCH(2)CH(2)OH中心点H2O。对其化学成分、晶体结构、形貌、生长机理和热行为进行了详细的表征。析出的Zn2Ti3-GAH具有高结晶性的单斜相和多孔微棒形态。作为单源前驱体（SSP）， Zn2Ti3-GAH通过热分解转化为不同相的钛酸锌。在微棒形状不变的情况下，分别在500℃和700℃下煅烧得到立方相Zn2Ti3O8和金红石型TiO2 （r-TiO2）负载的六方相ZnTiO3 (h-ZnTiO3)；而r-TiO2负载的Zn2TiO4在较高的温度下（950℃）以分散的颗粒或链的形式生成。得益于SSP路径和前驱体特定微棒域的限制，在可编程煅烧过程中形成了r-TiO2-ZnTiO3和r-TiO2-Zn2TiO4的异质结构。紫外光催化降解亚甲基蓝（MB）的研究表明，转化后的钛酸锌具有增强的光催化活性。其中，r-TiO2负载的h-ZnTiO3的光降解速率常数为0.00163 s(-1)，与市售的德固赛P25 TiO2相当。这可能与填充在微棒中的r-TiO2-ZnTiO3异质结构中电荷分离更有效有关。
A heterobimetallic complex, zinc titanium glycolate acetate hydrate (Zn2Ti3-GAH), tentatively formulated as Zn2Ti3(OCH2CH2O)(4)(OCH2CH2OH)(5)(CH3COO)(3)center dot 2HOCH(2)CH(2)OH center dot H2O, was synthesized by a room-temperature homogeneous precipitation in ethylene glycol solution. Its chemical composition, crystal structure, morphology, growth mechanism and thermal behaviors were characterized in detail. The precipitated Zn2Ti3-GAH was of a highly crystalline monoclinic phase and porous microrod morphology. As the single source precursor (SSP), Zn2Ti3-GAH was transformed into different phases of zinc titanate via thermal decomposition. With the remaining shape of the microrods, cubic phases of Zn2Ti3O8 and rutile TiO2 (r-TiO2) supported hexagonal phases of ZnTiO3 (h-ZnTiO3) were obtained by calcination at 500 and 700 degrees C, respectively; while r-TiO2 supported Zn2TiO4 were yielded in the form of dispersed particles or chains at higher temperature (950 degrees C). Benefiting from the SSP route and the confinement in the specific microrod domains of precursors, the heterostructures of r-TiO2-ZnTiO3 and r-TiO2-Zn2TiO4 were formed during programmable calcination. The studies on photocatalysis by degrading methylene blue (MB) under ultraviolet (UV) irradiation indicated that the as-transformed zinc titanate exhibited enhanced activity. In particular, r-TiO2 supported h-ZnTiO3 displayed the photodegradation reaction rate constant of 0.00163 s(-1), which was comparable to that of commercially available Degussa P25 TiO2. This probably related to the more effective charge separation in the r-TiO2-ZnTiO3 heterostructure packed in the microrods.