Electrochemical synthesis of zeolite-like ruthenium-based hexacyanometalates multi-film assemblies

Abstract

Electrochemical synthesis of zeolite-like films of K + x Ru y [Fe(CN) 6] z (RF) or ruthenium hexacyanoferrate and K + x Ru y [Ru(CN) 6] z (RR) or ruthenium hexacyanoruthenuate, and related compounds have been achieved using cyclic voltammetric technique. Formation of porous multi-film assemblies of Prussian Blue (PB) and RF was carried out by either direct electrodeposition of PB over RF or RF over PB during repetitive potential cycling, or by electrochemically driven insertion–substitution methods. The cyclic voltammetric studies indicate that the method of preparation has no effect on the overall electrochemical (EC) behavior of the formed assemblies. In all studied cases, the EC of all redox centers in the multi-films was observed regardless of their order in the assembly. Substitution of a counter ion In 3+ or Cu 2+ results in less stable assemblies. Studies indicate that whenever Ru 3+ serves as the counter ion in hexacyanometalates (HCM), the redox potential of the complex center ([M z+ (CN) 6]) is shifted to a more negative potential. Some of these multi-film assemblies demonstrated catalytic activities in the oxidation of hydrazine.