Electrodeposition and characterization of Pt coatings on Ti for electrooxidation of cyanide

Abstract

Cyanide solutions used in industry are harmful not only to humans but also to other living organisms. The development of low cost and simple in preparation electrodes for cyanide electrochemical destruction is an important requirement. Ti electrodes galvanostatically covered with a Pt layer of 120, 300 and 600 nm average thickness were chosen as the anodes for electrochemical oxidation of high concentration (0.1 M) cyanide solutions. The morphology and microstructure of Pt coatings were observed by using scanning electron microscopy (SEM) and X-ray diffraction (XRD) methods. It was found from XRD data that the average Pt crystallite size is equal to 9.3 ± 0.5 nm regardless of whether the electrode has been exploited for cyanide electrochemical destruction. Electrocatalytic activity of platinized Ti electrodes was tested by determining the current efficiencies of cyanide electrooxidation that were found to be equal to 60% thus showing high effectiveness of the process. The obtained results indicate that electrocatalytic properties of the electrodes change over time as the oxidation of cyanide is carried out. Nevertheless, a Ti electrode galvanostatically covered with a Pt layer of 600 nm average thickness shows higher stability, making it applicable for effective anodic utilization of cyanide ions.