Mechanistic aspect of copper selenide as an electrocatalyst for the detection of hydrogen peroxide in gaseous phase

Abstract

The electrocatalytic properties of copper selenide for hydrogen peroxide detection in a gas phase were investigated using cyclic and square-wave voltammetry. Copper selenide demonstrated significant electrocatalytic activity towards hydrogen peroxide oxidation in a basic medium containing polyacrylic acid as a gas-absorbing polyelectrolyte. Experimental data were corroborated by a brief theoretical analysis and simulations based on a two-electron irreversible electrode mechanism of a dissolved redox couple. The voltammetric response of a conventional glassy carbon electrode modified with copper selenide showed a linear correlation with hydrogen peroxide concentration over a range of 3.0 × 10 −5 to 1.0 × 10 −3 mol L −1 in solution. Practical application of this method for gaseous hydrogen peroxide detection was explored using screen-printed electrodes (SPE) coated with a thin film of polyacrylic acid containing medium, with copper selenide serving as a modifier of the working electrode. The detectable concentration range of gaseous hydrogen peroxide using the modified SPE spanned picomolar concentrations. The statistical parameters of the calibration line in terms of LOQ, LOD and R 2 are 4.1 × 10 −6 , 1.2 × 10 −6 mol L −1 , and 0.996, which correspond very closely to the gas concentrations of 6.1 × 10 −12 to 6.1 × 10 −11 mol L −1 . The H 2 O 2 is detected not only in the solution phase via CV and SWV, but also measured in gas phase via SWV with SPE modified with copper selenide nanobelts as an electrocatalyst for the oxidation of H 2 O 2 . • Copper selenide based H 2 O 2 detection in gas phase with theoretical verification. • PAA plays major role for the adsorption of gaseous H 2 O 2 from environment. • The catalyst show capability for the detection up to sub-micromole. • The high response is due to the combination of unique features of Cu and Se.

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