Electrogenerated Chemiluminescence by in Situ Production of Coreactant Hydrogen Peroxide in Carbonate Aqueous Solution at a Boron-Doped Diamond Electrode
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2019-12-29 |
| Journal | Journal of the American Chemical Society |
| Authors | Irkham Irkham, Andrea Fiorani, Giovanni Valenti, Naoki Kamoshida, Francesco Paolucci |
| Institutions | Keio University, University of Bologna |
| Citations | 101 |
Abstract
Section titled āAbstractāAn electrogenerated chemiluminescence (ECL) system by in situ coreactant production, where Ru(bpy)<sub>3</sub><sup>2+</sup> emission is generated at a boron-doped diamond (BDD) electrode, is presented. The system takes advantage of the unique properties of BDD to promote oxidation of carbonate (CO<sub>3</sub><sup>2-</sup>) into peroxydicarbonate (C<sub>2</sub>O<sub>6</sub><sup>2-</sup>), which further reacts with water to form hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), which acts as a coreactant for Ru(bpy)<sub>3</sub><sup>2+</sup> ECL. Investigation of the mechanism reveals that ECL emission is triggered by the reduction of H<sub>2</sub>O<sub>2</sub> to hydroxyl radicals (OH<sup>ā¢</sup>), which later react with the reduced Ru(bpy)<sub>3</sub><sup>+</sup> molecules to form excited states, followed by light emission. The ECL signal was found to increase with the concentration of CO<sub>3</sub><sup>2-</sup>; therefore, with the concentration of electrogenerated H<sub>2</sub>O<sub>2</sub>, although at the same time, higher concentrations of H<sub>2</sub>O<sub>2</sub> can quench the ECL emission, resulting in a decrease in intensity. The carbonate concentration, pH, and oxidation parameters, such as potential and time, were optimized to find the best emission conditions.