Electrochemistry of Copper in Polyacrylic Acid: The Electrode Mechanism and Analytical Application for Gaseous Hydrogen Peroxide Detection

Abstract

Electrode reaction of copper(II) reduction in an aqueous solution of polyacrylic acid (PAA) is studied by means of cyclic staircase and square-wave voltammetry to establish a basis for an electrochemical sensor for gaseous hydrogen peroxide detection. It has been determined that the reduction mechanism at a glassy carbon electrode follows a two-step, consecutive electron transfer reaction scheme of Cu2+ to the final copper solid deposit, via the formation of the intermediate Cu+ ions, which are subject to a fast disproportionation reaction. Experimental data have been supported by theoretical considerations and simulations based on EC’E electrode mechanism, where E designates an electrode reaction, whereas C’ is a homogeneous regenerative chemical reaction. Estimated thermodynamic and kinetic data of the electrode mechanism suggest stabilization of the intermediate Cu+ form by PAA in comparison with a pure aqueous medium. Commercially available screen-printed carbon electrodes were covered with a film of 1% (mass percent) of aqueous PAA solution containing Cu2+ ions, which proves to be a promising platform for gaseous H2O2 detection, where the Cu2+/Cu+ couple serves as a redox mediator for H2O2 reduction, with a limit of detection at a sub-μg dm–3 concentration level in the gas phase.

Simple and Intelligent Electrochemical Detection of Ammonia over Cuprous Oxide Thin Film Electrode

“…It might be speculated that, at a sufficiently positive potential, all of the Cu 2 O was converted to CuO, whereas it subsequently reduced to Cu 2 O during the cathodic scan. The reduction of CuO was immediately followed by the reduction of Cu 2 O into metallic copper (Cu) and, characteristically, the peak position of the second reduction was more negative as per literature interpretations [36,59]; however, in phosphate buffer medium, a second reduction peak was not observed. While, in the anodic scan, the oxidation of deposited Cu should produce two peaks; however, the oxidation of deposited Cu at the interface was not limited by diffusion, so most of the Cu appeared as Cu 2 O at the interface and, upon reverting the potential sweep in the positive direction, only one oxidation peak (~−0.07) was observed due to Cu 2 O converting into CuO in the form of a well-defined semi-reversible peak.…”

“…There has been much interest in electrochemical sensing applications of Cu 2 O NPs due to their narrow band gap and excellent electrical properties [36]. As a result, various synthesis routes have been employed to obtain Cu 2 O NP-fabricated GCE.…”

Bacterial Cellulose–Based MOF Hybrid as a Sensitive Switch Off–On Luminescent Sensor for the Selective Recognition of l-Histidine

“…Moreover, the electrode potential of Cu 2+ /Cu is 0.34 eV, located between the conduction band (CB) and VB of UN , leading to an impetus for the PET mechanism from UN to Cu 2+ (Figure S16c). − Thus, the nonemissive d–d transitions among these levels resulted in the strong reabsorption and reduced energy transfer efficiency of LMCT radiation of LMOF. Consequently, electron transition in luminescence emission of LMOF was restrained, resulting in luminescence quenching.…”

Design of metal oxide nanoparticles‐embedded polymeric nanocomposites for hydrogen peroxide chronoamperometric sensor

“…PAA is renowned for its exceptional absorption qualities and high degree of biocompatibility. These attributes have made it a popular option for electrochemical research and its efficacy has been partially confirmed in studies involving hydrogen peroxide measurement 30,31 . Moreover, it has been proposed that coating metal oxide (MO) nanoparticles with PAA can enhance their chemical stability in electronic devices.…”

“…These attributes have made it a popular option for electrochemical research and its efficacy has been partially confirmed in studies involving hydrogen peroxide measurement. 30,31 Moreover, it has been proposed that coating metal oxide (MO) nanoparticles with PAA can enhance their chemical stability in electronic devices. Consequently, there is a growing interest in developing PAA-based composites that incorporate different MO nanoparticles into the PAA matrix.…”