Electrochemical study of a new non-heme iron complex-modified carbon ionic liquid electrode with electrocatalytic activity towards hydrogen peroxide reduction

In this study, a new non-heme iron complex was prepared by mixing FeCl3∙6H2O and 2,4,6-tris(2-pyridylmethylamino)-1,3,5-triazine (TPMATA) in ionic liquid 1-butyl-1-methylpyrrolidinium bis((trifluoromethyl)sulfonyl)amide (IL [BMP+][TFSA−]). The iron complex (TPMATA-FeCl3) was used as a modifier for preparing the TPMATA-FeCl3-modified carbon ionic liquid electrode (TPMATA-FeCl3/CILE). H2O2 was electrocatalytically reduced at the TPMATA-FeCl3/CILE in neutral aqueous solutions via Fenton's mechanism in which hydroxyl radical,
- OH, was produced, and the radical was detected by using a fluorescence probe. This electrode showed a sensitivity of 22.1 μA∙mM−1 and a dynamic range of 0.025∼4.69 mM with a regression coefficient R2 of 0.993 (or 0.025∼0.765 mM, R2 = 0.997, sensitivity = 27.6 μA∙mM−1). The detection limit was 0.0125 mM (S/N = 3). This electrode shows the potential to be used as an electrochemical H2O2 sensor or for the production of hydroxyl radicals.