Electrocatalytic Oxidation of Alcohols, Sulfides and Hydrogen Peroxide Based on Hybrid Composite of Ruthenium Hexacyanoferrate and Multi-Walled Carbon Nanotubes

Abstract

An electrochemical sensor of alcohols, sulfides, and hydrogen peroxide (H2O2) has been investigated with hybrid composite of ruthenium hexacyanoferrate (RuHCF) and multi-walled carbon nanotubes (MWCNT). The formed MWCNT-RuHCF composite was examined in acidic solution and found four characteristic redox couples revealed RuHCF redox process. It was stable and found higher current response when RuHCF hybrid with MWCNT. It showed good electrocatalytic oxidation to alcohols including ethanol, propanol, isopropanol, and sulfides including L-cysteine, thiosulfate, respectively. Particularly, both electrocatalytic oxidation and reduction of H2O2 can be performed by this composite. Applied potential at -0.1 V, it showed a linear range of 0-1.2×10-4 M, with a detection limit of 10-5 M (S/N = 3) and a significant sensitivity of 123.2 μA mM-1 cm-2. Ethanol, propanol, and isopropanol were determined at +1.05 V, +1.15 V, and +1.23 V, respectively. Linear range of 2×10-4-1.7×10-3 M, 4×10-4-1.7×10-3 M, and 0-8×10-4 M were estimated for these alcohols. The sensitivity was 4548.4 μA M-1 cm-2, 12544.6 μA M-1 cm-2, 38543.1 μA M-1 cm-2, with detection limit of 10-4 M, 10-5 M, and 10-5 M (S/N = 3), respectively.