Preparation and characterization of CePtCl6 films and their electrocatalytic properties with NAD+, l-cystine and sulfur oxoanions

Cerium hexachloroplatinate (CePtCl6) films have been prepared by mixing Ce3+ and PtCl 6 2 - ions in an aqueous KCl pH 3.0 solutions. The deposition of a cerium hexachloroplatinate film occurred when Pt IV Cl 6 2 - was electrochemically reduced to Pt II Cl 6 4 - and Ce4+ to Ce3+. The electrochemical quartz crystal microbalance (EQCM), UV–visible absorption spectroscopy, stopped-flow kinetic method, amperometry and cyclic voltammetry techniques were used to study the deposition and growth mechanism of the cerium hexachloroplatinate films. The electrochemical properties of this film indicated a single redox process which was corresponding to reduction of Pt IV Cl 6 2 - to Pt II Cl 6 4 - immobilized cerium hexachloroplatinate films. In the aqueous KCl pH 3.0 solution, Pt IV Cl 6 2 - was electrochemically reduced to Pt II Cl 6 4 - and the Ce3+ reacted with the film to maintain the electrochemical neutrality. The reversibility of the cerium (III) hexachloroplatinate film during cycling and with changing frequency has been found good, and the Ce3+ ion exchange obviously occurred in the redox couples. The electrocatalytic reduction properties of (β-nicotinamide adenine dinucleotide) NAD+, l-cystine, SO 5 2 - and S 4 O 6 2 - were determined using the cerium hexachloroplatinate films. The electrocatalysis and electrochemical reactions of NAD+ with cerium hexachloroplatinate film were measured by amperometry using the rotating disk electrodes.