Exploring a cost-effective alternative to noble metals for electrocatalytic oxidation and ethanol detection in alkaline media

The electrocatalytic oxidation of ethanol in an alkaline medium was systematically investigated using both commercial electrodes (GCE, ITO, Pt, Gr, and SPE) and CuO based modified electrodes (CuO/ITO, Ag/CuO/ITO, and rGO/CuO/ITO). The CuO films were deposited onto ITO substrates via spray pyrolysis, while Ag and rGO were introduced through thermal evaporation and the doctor blade method, respectively. Structural characterization confirmed the polycrystalline nature and high elemental purity of the synthesized CuO based materials. Electrochemical studies were conducted in 0.5 M NaOH with varying ethanol concentrations, using cyclic voltammetry (CV) to evaluate catalytic behavior with a potential window of -0.1 to 0.2 V. The CuO based electrodes, especially those functionalized with Ag and rGO, demonstrated significantly enhanced electrocatalytic activity compared to their commercial electrodes. These modified electrodes exhibited lower oxidation potentials, improved sensitivity, and reduced saturation effects at higher ethanol concentrations (oxidation peak at -0.2 – 2.0 V). The enhancements are attributed to increased active sites and the synergistic interaction between CuO and the functional materials. Among the tested electrodes, Ag/CuO and rGO/CuO showed the most promising performance, offering stable, sensitive, and cost-effective alternatives to traditional Pt-based catalysts for ethanol sensing applications.

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