Rotating copper disk electrode studies of the mechanism of the dissolution-passivation step on copper in alkaline solutions

The Electrochemical Response of Single Crystalline Copper Nanowires to Atmospheric Air and Aqueous Solution

“…Further analysis shows that the Cu 2 O layer (L1) also has parallel orientation relationship (i.e., {1 1 1} lattice plane) with the CuNW matrix, as proved by the HRTEM image (Figure e). The formation of the L1 also follows the SSR mechanism as shown in Equation . H′ and I′ are two FFT reciprocal patterns that are transformed from L3 in the areas marked as H and I in Figure d, which are identified to be reflected from randomly oriented CuO and Cu(OH) 2 , respectively.…”

“…Subsequently, the obtained species will redeposit onto the CuNWs' surface forming L3. [7a,9] As a result, the oxide film formed on CuNW subject to the high potential of +0.45 V becomes much thicker than the thickness of the film formed on CuNW at the low potential of −0.15 V.…”

“…At such a high potential, the inner epitaxial Cu 2 O layer is fully oxidized into disordered CuO through violent reaction , which is then incorporated with CuO in both L2 and L3 to form disordered inner CuO layer. At the same time, the rapid growth of the small Cu(OH) 2 crystals located at the outer part in L3 produces a boundary between the inner CuO layer and outermost Cu(OH) 2 layer, which appears clearer as a result of the hydration and dehydration processes between CuO and Cu(OH) 2 following Equation , i.e. …”

The Role of Carbon on Copper–Carbon Composites for the Electrooxidation of Alcohols in an Alkaline Medium

“…Consequently, the cathodic peaks may undergo shifting of peak potentials associated with the reduction of CuO/Cu(OH) 2 to Cu 2 O and the reduction of Cu 2 O to Cu, as a function of the experimental conditions such as electrolyte [7,9,10] or the use of nanoparticulate copper electrodes (vide infra). As seen, the undoped carbon electrode displayed a pseudo-rectangular shape due to the dominant contribution of a capacitive intensity (ic), which is in agreement with its textural features ( Table 1).…”

“…Beyond their low cost and availability, transition metals exhibit high catalytic activities and coulombic efficiencies in a plethora of electrochemical processes where they are employed, with nickel, copper and cobalt, among others, being the most representative. Particular emphasis is placed on the use of copper due to its rich redox chemistry, with multiple reductive and oxidative reactions catalyzed by different copper complexes and oxides obtained as a function of applied electric potential; i.e., the reduction of Cu(II) species to either Cu(I) or Cu(0) species, and then the oxidation to Cu(II) or Cu(III), which in some cases are redox species with limited solubility in alkaline media [6][7][8][9][10]. Several works have shown copper-based electrodes as active catalysts in multiple processes such as electroanalysis and sensors [11][12][13][14], electrooxidation of small organic molecules [15,16], fuel cells [14,17], organic electrosynthesis [18], water oxidation [19,20] and hydrogen evolution [20,21].…”