Poly-(1,10-phenanthroline) – Synthesis, Properties, and Electrochemical Applications

The stages of electrochemical polymerization of the 1,10-phenanthroline complex with Fe 2+ ([Fe(phen) 3 ] 2+ ) were studied using cyclic voltammetry. It was found that the oxidation of [Fe(phen) 3 ] 2+ involves four electrons, resulting in the formation of free radicals. The recombination of these radicals is the main mechanism of polymerization, as confirmed by the rate order of the reaction. Poly-(1,10-phenanthroline) undergoes Fenton hydroxylation, creating redox-active sites in the polymer structure. This increases its electrical conductivity. The modification of an electrode with a polymer containing poly-(1,10-phenanthroline) and sulfanylic acid yielded the most promising results, increasing the number of active sites and shifting the reduction potential to more positive values. The electrochemical behavior of poly-(1,10-phenanthroline)-modified electrodes in relation to various redox systems has revealed the highest electrocatalytic activity towards the I 2 /I − redox couple. This makes this material promising for application in fuel cells.