文摘
Paired (simultaneous) electrochemical processes can increase energy savings in selected cases by using the reactions at both electrodes of an electrochemical cell to perform a desired process, as is the case in the commercially successful chlor-alkali process. In the demonstration described herein, simultaneous blue electrochemiluminescence (ECL) is obtained with luminol in a basic medium in a divided electrochemical cell. ECL is obtained in the anolyte through the direct oxidation of luminol, the reaction products of which interact with H2O2 in the vicinity of the electrode to yield an excited emitting species. ECL is also obtained in the catholyte through an indirect, mediated process involving the initial reduction of ClO2鈥?/sup> to ClO鈥?/sup>, which then reacts with luminol and H2O2 to produce the excited emitting species. The co-reactant (H2O2) is needed to complete the reaction sequences in both compartments of the cell. This ECL phenomenon is visible to the naked eye in a darkened room at a distance of up to 5 m.
Keywords:
First-Year Undergraduate/General; Upper-Division Undergraduate; Analytical Chemistry; Demonstrations; Interdisciplinary/Multidisciplinary; Hands-On Learning/Manipulatives; Aqueous Solution Chemistry; Electrochemistry; Photochemistry