The Electrochemical Oxidation of Hydroquinone and Catechol through a Novel Poly-geminal Dicationic Ionic Liquid (PGDIL)–TiO(2) Composite Film Electrode

A novel poly-geminal dicationic ionic liquid (PGDIL)-TiO(2)/Au composite film electrode was successfully prepared by electrochemical polymerization of 1,4-bis(3-(m-aminobenzyl)imidazol-1-yl)butane bis(hexafluorinephosphate) containing polymerizable anilino groups in the electrolyte containing nano-TiO(2). The basic properties of PGDIL–TiO(2)/Au composite films were studied by SEM, cyclic voltammetry, electrochemical impedance spectroscopy, and differential pulse voltammetry. The SEM results revealed that the PGDIL–TiO(2) powder has a more uniform and smaller particle size than the PGDIL. The cyclic voltammetry results showed that the catalytic effect on electrochemical oxidation of hydroquinone and catechol of the PGDIL–TiO(2) electrode is the best, yet the R(ct) of PGDIL–TiO(2) electrode is higher than that of PGDIL and TiO(2) electrode, which is caused by the synergistic effect between TiO(2) and PGDIL. The PGDIL–TiO(2)/Au composite electrode presents a good enhancement effect on the reversible electrochemical oxidation of hydroquinone and catechol, and differential pulse voltammetry tests of the hydroquinone and catechol in a certain concentration range revealed that the PGDIL–TiO(2)/Au electrode enables a high sensitivity to the differentiation and detection of hydroquinone and catechol. Furthermore, the electrochemical catalytic mechanism of the PGDIL–TiO(2)/Au electrode was studied. It was found that the recombination of TiO(2) improved the reversibility and activity of the PGDIL–TiO(2)/Au electrode for the electrocatalytic reaction of HQ and CC. The PGDIL–TiO(2)/Au electrode is also expected to be used for catalytic oxidation and detection of other organic pollutants containing –OH groups.