Surface-renewable graphite organosilicate composite electrode bulk-modified with a bifunctional electrocatalyst containing tris(2,2′-bipyridine) ruthenium(II) and 18-molybdosulfate

The electroactive composite containing tris(2,2′-bipyridine) ruthenium(II) and 18-molybdosulfate (RuS2Mo18) was used as a bifunctional electrocatalyst to fabricate a chemically bulk-modified graphite organosilicate composite electrode (GOSE) by a sol–gel process for the first time. RuS2Mo18 covered the graphite particles homogeneously with the aid of solvent; the silicate provided a rigid porous backbone, and the methyl groups endowed hydrophobicity and thus limited the wetting section of the modified electrode. The electrochemical behavior of the RuS2Mo18–GOSE in aqueous solution was studied by cyclic voltammetry. The RuS2Mo18–GOSE presents good electrocatalytic activity not only toward the reduction of bromate, which is attributed to the function of the 18-molybdosulfate, but also toward the oxidation of arsenite, which is attributed to the function of the tris(2,2′-bipyridine) ruthenium(II). Another remarkable advantage of the RuS2Mo18–GOSE is its good stability and reproducibility of surface renewal by simple polishing in the event of surface fouling.