Zhang Rui, Qin Libo, Iqbal Arshad, Zhou Yunshan, Zhang Lijuan, Ren Haizhou, Lv Xiaofei, Li Minglei
State Key Laboratory of Chemical Resource Engineering, Institute of Science, Beijing University of Chemical Technology, Beijing 100029, P. R. China.
Dalton Trans. 2017 Jul 18;46(28):9068-9075. doi: 10.1039/c7dt02046e.
Currently, the realization of rationally designed architectures based on polyoxometalates (POMs) with designed functions has mostly been achieved through the preparation of functional films. However, the traditional approaches suffer from the drawbacks such as time-consuming processes, ill-defined structure and quality, random orientation of the POM molecules, and unsatisfactory performance. In this study, microcrystals of Ag[EuWO]·36HO (denoted as Ag[EuWO]) were synthesized via a titration method by treating Na[EuWO]·32HO (denoted as Na[EuWO]), selected as a prototype, with Ag, leading to the formation of a water-insoluble crystalline powder with a uniform hexagonal platelet morphology. After this, a simple yet efficient manual assembly method was used to rapidly manufacture AgEuWO microcrystal thin films on a glass substrate with high coverage, high crystallinity, and highly preferential orientation. Note that the as-prepared films emit orange polarized fluorescence with an anisotropy value of about 0.21, which places them among the materials of largest anisotropy. It is expected that the manual assembly approach can be generally adopted for the fabrication of many other kinds of polyoxometalate-based materials on various substrates for practical applications.
目前，基于具有特定功能的多金属氧酸盐（POMs）来实现合理设计的结构，大多是通过制备功能薄膜来达成的。然而，传统方法存在诸多缺点，如过程耗时、结构和质量不明确、POM分子取向随机以及性能不尽人意等。在本研究中，通过滴定法，用银处理选为原型的Na[EuWO]·32H₂O（记为Na[EuWO]），合成了Ag[EuWO₄]·36H₂O（记为Ag[EuWO₄]）微晶，得到一种具有均匀六方片状形态的水不溶性结晶粉末。此后，采用一种简单而高效的手动组装方法，在玻璃基板上快速制造出具有高覆盖率、高结晶度和高度择优取向的AgEuWO₄微晶薄膜。注意，所制备的薄膜发出橙色偏振荧光，各向异性值约为0.21，这使其跻身于各向异性最大的材料之列。预计这种手动组装方法可普遍用于在各种基板上制备许多其他种类的基于多金属氧酸盐的材料，以用于实际应用。
