An electrocatalytic oxygen reduction by copper nanoparticles-modified Au(100)-rich polycrystalline gold electrode in 0.5 M KOH

Fractional determination of peracetic acid and hydrogen peroxide at deposited gold enriched in the Au(1 1 1) domain

“…For instance, for a short-chain thiol species like cysteine, a multiple reductive desorption pattern is recorded for the reductive desorption from a poly-Au electrode in alkaline media. These peaks can be assigned to different binding strengths of the cysteine to the different domains of the poly-Au electrode, i.e., Au(1 1 1), Au(1 0 0) and Au(1 1 0) [27][28][29]. The relative ratio of the individual areas under these desorption peaks is thus considered to reflect the relative ratio of the lowindex single-crystallographic orientations constituting the surface of the Au substrate.…”

“…3 It becomes clear that the largest separation between the peak potentials for the reduction of PAA and H 2 O 2 is obtained at the Au cit /GC electrode. This finding could be explained as follows; crystallographic orientation is well known to significantly affect the electrocatalytic properties of electrodes toward several electrochemical reactions [26][27][28][29]. For instance, the oxygen reduction reaction (ORR), and consequently H 2 O 2 reduction, is inherently dependent on the crystallographic orientation of the Au electrode [30].…”

“…Hence, several species have shown multiple reduction peaks at the different facets of a polycrystalline electrode [32]. Moreover the atomic arrangement on some facet may enhance a preferential adsorption of an intermediate resulting in different electroreduction products, for instance, Au(1 1 1) facet supports a quasi-reversible 2-electron reduction pathway for oxygen reduction as a result of an end-on adsorption mode, whereas Au(1 0 0) supports a direct 4-electron reduction as a result of a parallel adsorption mode [29,34]. In the present case, the different facets of poly-Au electrode have different PZC values; Au(1 1 1) 0.285 V, Au(1 0 0) 0.140 V and Au(1 1 0) −0.015 V vs. saturated calomel electrode [32].…”

Fractional Analysis of Ascorbic Acid and Dopamine by Copper Nanoparticles Electrodeposited onto Gold Electrode

“…Metal nanoparticles with their unique electrocatalytic properties, compared with their metal counterparts, have been applied in a wide spectrum of applications [1][2][3][4][5][6][7][8][9] . They have size dependent unique optical, electrical and chemical properties and are very hopeful for everyday applications in various research areas, like molecular catalysts, multifunctional reagent and biosensors.…”

“…They have size dependent unique optical, electrical and chemical properties and are very hopeful for everyday applications in various research areas, like molecular catalysts, multifunctional reagent and biosensors. In many cases, the sluggish electrochemical behavior of several compounds was enhanced via the tailored nanoparticles modified electrodes, and also for the solution of the fouling of some bulk materials 5,9 . For example, the electrochemical behavior of dopamine (DA) at polycrystalline gold electrode is unstable, and after few cycles at poly-Au electrodes, the electrode is fouled and the electro-oxidation of the dopamine is largely retarded.…”