Cyclic voltammetry as a tool for model testing of catalytic Pt- and Ag-doped carbon microspheres

This paper deals with comparison of modified carbon electrodes prepared from Pt- and Ag-doped carbon microspheres using cyclic voltammetry of [Fe(CN)₆]^{3 -}/[Fe(CN)₆]^{4 -} redox pair as a probe under various experimental conditions. Spherical particles ranging from 0.5 to 8 μm in average as evidenced by SEM showed slight influence of dopant nature onto their microstructure. FTIR analysis revealed that the involvement of metal species in the carbon structure was followed by their subsequent reduction and rising of oxidized carbon functionalities in the spectra. Electrochemical study showed that all the examined electrodes performed reversible processes with chemically stable generated products and no side chemical reactions. Among them, Pt-doped electrode showed superior electrocatalytic behavior in terms of heterogeneous transfer rate constant and other kinetic parameters. Since minimal addition of Pt in the hydrothermal synthesis resulted in powerful electrocatalytic effect as precious advantage, benevolent impact of carbon microspheres as catalyst support was put into focus of this research.