A general strategy for the preparation of polyoxometalate coordination polymer modified electrodes via an ionic liquid route and their electrocatalytic activities

A general strategy for the preparation of polyoxometalate coordination polymer modified electrodes via an ionic liquid route was proposed. A polyoxometalate (POMs) coordination polymer 1, [H2bpy]2[{Cu(bpy)2}Mo5P2O23]⋅4H2O (bpy = 4,4′-bpyridine) was successfully reconstructed by electrolyzing in its ionic liquid solution on conducting glasses electrode coated with indium tin oxide (ITO). Polymer 1 is soluble in the an ionic liquids (ILs) 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4), not soluble in water and common organic solvents such as DMF, ether. The reconstructed polyoxometalate coordination polymer on the ITO electrode was characterized by XPS and XRD. XPS spectrums and the XRD patterns of the deposited POMs on ITO electrode show the deposited POMs had the same structure as the polyoxometalate coordination polymer 1, which imply that the structure of the deposited POMs on ITO electrode keeps the same as the original the polyoxometalate coordination polymer 1. Cyclic voltammetry technique was used to study the electrochemical properties of the as-prepared POM modified ITO electrode. The results implied that it had not only a good electrocatalytic activity toward the reduction of iodide, but also a high stability in aqueous solution. The proposed strategy for the construction of POMs coordination polymer modified electrode shows remarkable advantages, which should be important for practical applications.