Electrochemical preparation of VPtCl6 film and its electrocatalytic properties with NAD+ and sulfur oxoanions

A modified electrode with vanadium hexachloroplatinate (VPtCl6) film has been fabricated directly from the mixing of V2+ and PtCl 6 2- ions, and its electrochemical behavior was investigated. The deposition of a VPtCl6 film occurred when PtIV Cl 6 2- was electrochemically reduced to PtII Cl 6 2- and V3+ to V2+. The electrochemical quartz crystal microbalance (EQCM), ultraviolet-visible absorption spectroscopy, stopped-flow, chronoamperometry, and cyclic voltammetry techniques were used to study the deposition and growth mechanism of the above film. In the EQCM studies, the reversibility of the vanadium (II/III) hexachloroplatinate film during cycling and the corresponding frequency change was found to be good, and the V2+ ion exchange obviously occurred in the redox couple. For the surface morphological analysis, the film was further electrochemically deposited on a transparent semiconductor indium tin oxide (ITO) electrode for scanning electron microscopy and atomic force microscopy studies. It was found that the deposited VPtCl6 film formed as a film with platinum and vanadium particles on ITO. To validate the electroanalytical properties, a VPtCl6 -modified glassy carbon electrode was applied for the electrocatalytic reduction of the NAD+ (Β -Nicotinamide adenine dinucleotide) and sulfur oxoanions, and the results showed a quite effective electrocatalytic reduction for the corresponding substances.