CuO/Cu2O nanoparticles: A simple and green synthesis, characterization and their electrocatalytic performance toward formaldehyde oxidation

A simple, low cost, stable and sensitive electrochemical sensor based on copper oxide nanoparticles (CuO/Cu2O NPs) was developed for oxidation of formaldehyde. CuO/Cu2O NPs were synthesized with a green and low cost method in the presence of Gum Arabic. During the synthesis process, Gum Arabic acted as a stabilizing agent. The morphology, crystal structure and chemical composition of as-prepared CuO/Cu2O nanostructure were performed through field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction techniques. The CuO/Cu2O NPs modified carbon ionic liquid electrode (CuO/Cu2O/CILE) was designed and its catalytic activity was investigated toward formaldehyde oxidation. Compared with bare carbon ionic liquid electrode, the modified electrode exhibited efficient catalysis to direct formaldehyde oxidation. The obtained results show CuO/Cu2O/CILE electrode indicates good electrocatalytic activity toward formaldehyde oxidation with a linear range from 0.1 mmolL−1-110 mmolL−1 and a limit of detection of 10 μmolL−1. Moreover, the prepared electrode exhibited good long term stability and good reproducibility. A simple and green route for synthesis of CuO/Cu2O NPs together with good electrocatalytic activity toward formaldehyde oxidation show that the CuO/Cu2O/CILE is one of the most promising systems for detection of formaldehyde.