Abstract
Gold decorated glassy carbon electrodes (Au/GC) are examined for the simultaneous electroanalysis of peracetic acid (PAA) and hydrogen peroxide (H2O2) in their coexistence and the results are compared with those obtained at the polycrystalline gold (poly-Au) and single crystalline gold electrodes. Gold is electrodeposited from 1mM Na[AuCl4] solutions in the presence of either Cl− (AuCl/GC) or citric acid (Aucit/GC) and in their absence (Aunon/GC). The two well-defined and separated peaks for the reduction of PAA and H2O2 were obtained in acetate buffer solutions (pH 4.7). Among the electrodes studied, i.e., poly-Au, Aunon/GC, Aucit/GC and AuCl/GC electrodes, the largest peak current and the most positive peak potential for the PAA reduction were obtained at the Aucit/GC electrode. The reason behind the high catalytic activity obtained at the Aucit/GC electrode is attributed to the fact that this electrode is enriched in the Au(111) domain, based on the PAA and H2O2 electroreduction at the single crystalline gold electrodes where the highest electrocatalytic activity toward PAA reduction was obtained at Au(111) single crystalline gold electrode. A significantly large peak separation in the PAA and H2O2 reduction at the Aucit/GC electrode enabled the simultaneous electroanalysis of PAA and H2O2 in the presence of high concentration of H2O2 (ca. 0.05M) in their aerated solutions.