A Novel 12-Tungstovanadate Doubly-Grafted by Zn-Complexes: Synthesis, Crystal Structure and Properties

A novel vanadium-centered tungstovanadate, {[Zn(phen)2(H2O)]2[VW12O40]}·3H2O (1) (phen = 1,10-phenanthroline), has been hydrothermally synthesized and characterized by elemental analysis, single-crystal X-ray diffraction, IR spectroscopy and thermogravimetric analysis. Single-crystal X-ray diffraction at 293 K reveals that 1 consists of a [VW12O40]4− Keggin unit doubly-grafted by a [Zn(phen)2(H2O)]2+ complex. The modified carbon-paste electrode of this tungstovanadate displays good electrocatalytic activity not only towards normal inorganic molecules NO2 −, BrO3 − and H2O2, but also biological molecule vitamin C. To some extent, this work shows that vanadium can be introduced into a polyoxometalate-modified electrode to facilitate catalytic oxidation or reduction of some chemical materials. Furthermore, this tungstovanadate shows high photoactivity with respect to degradation of methylene blue.