Electrochemical behaviour of serpentinite and forsterite in ferri/ferro cyanide benchmark redox system

Abstract

Serpentinite rock collected near Kopaonik Mountain in Serbia is considered as a multiphase assemblage mostly consisting of mineral lizardite. Forsterite has been obtained by chemical-thermal treatment of grounded sample of serpentinite. Electrochemical features of these two materials were investigated by using modified carbon paste electrode (CPE) which included mixing analytes, graphite powder and parafin oil as a binder and packing the mixture in a Teflon holder. Morphological and structural characteristics of the samples were analyzed by SEM and XRD techniques which revealed presence of certain crystal phases and agregates of irregular shapes sized from 10 to 40 μm. Cyclic voltammetry was employed to study their electrochemical characteristics. The peak current height and peak-to-peak separation showed that the electrochemical reaction is quasi-reversible. Kinetic parameters were derived from Tafel analysis. Calculated kinetic parameters indicated prominent electrocatalytic effect of the minerals for ferri/ferro cyanide redox reaction in aquaeous solution