Syntheses And Properties Of Proton Conductors And Their Composites Based On Keggin Anions And Copper Coordination Compounds

With the development of the science and technology in the modern society, the study of functional materials have been changed, especially the organic-inorganic hybrid materials based on functional materials are the main trend in the development of modern materials. The organic-inorganic hybrid materials make a hybrid by two or more different chemical compositions and improve the materials of the functional properties. And this kind of functional material has important applications on the new energy, biological medicine and so on in today’s society. Heteropolyacid is essential in the components of the functional material. And it has a broad application prospect in the preparation of functional materials because of its unique structure, abundant physical and chemical properties. We know that heteropolyacid is a kind of uniform intensity proton acid, and it is not only has a nature of strong acid, but also has a wealth of oxidation-reduction property, we can adjust the acid strength and the property of oxidation-reduction of the heteropolyacid by changing the molecular composition. At the same time, the heteropolyacid is a kind of multi-functional and new-type catalyst, the stability of the heteropolyacid is good, and it has no pollution to the environment, so it is a kind of promising green catalyst. And the solid proton conductor in our group is studied and the Keggin-type heteropolyacids play an important role that can not be ignored in our research because of its unique discret ionic structure. So it can be used to construct the building blocks of the synthesis of the new functional materials. Like this kind of method that fixed the Keggin-type heteropolyacids on all kinds of solid substrates is quickly, simple, stable, controllable thickness and good reproducibility and so on.So in this paper, we have succeeded in constructing a new complex 1:{[Cu(L)(H2O)3]2 [SiW12O40]}-7H2O by the controllable self-assembly of 4,4’-dimethyl-2,2’-pyridine (L), transition metal ions Cu2+and Keggin-anions SiW12O404-. X-ray single crystal structure analysis showed that the complex crystallized in the monoclinic space group C2/c; Infrared analysis showed that the Keggin-tipe polyanion SiW12O404- and the ligand molecule L were in the complex; the result of thermal gravimetric analyses showed that its structure did not change below 100℃; X-ray powder diffraction analysis data indicated that the sample structure of the complex did not change before and after the conductivity measurement; AC impedance test results indicated that the complex achieved good proton conductivities 10"3 S·cm-1 in the temperature 100℃ under relative humidity range 35%-98%.Second, one new complex 2:[Cu4(dpdo)12][H(H20)27(CH3CN)12][PW12040]3 was succeeded in constructing based on 4,4’-bipyridine-N,N’-dioxide (dpdo) organic ligands, the first transition metal copper and the Keggin-anions PW12O404=. Then we did tests and data analysis to the crystal structure and property of the complex. We also prepared two new composites (2-GO1 and 2-GO2) dopped with different proportions of graphene oxide that based on the complex. And they had been compared with each other and tested by infrared analysis, thermal gravimetric analysis, X-ray powder diffraction analysis and scanning electron microscopy (SEM). The thermal gravimetric analysis results showed that the skeleton of the compound had a high thermalstability below 100℃; X-ray powder diffraction analysis data indicated that their structures did not change before and after the conductivity measurement; and we can see the graphene oxide on the surface of the complex 2 in a piece of layer structure through scanning electron microscopy (SEM). At last the AC impedance test showed that the proton conductivities of the two composites doped with graphene oxide (2-GO1 and 2-GO2) are better than complex 2.