Plant‐mediated fabrication of cobalt oxide nanoparticles and evaluation of their catalytic effects on electro‐oxidation of formaldehyde

Abstract

Cobalt oxide nanoparticles (Co3O4‐NPs) were synthesized by aqueous extract of Artemisia vulgaris plant at 50°C. The biosynthesized extract mediated Co3O4‐NPs were characterized through different methods containing FT‐IR (Fourier transform infrared spectroscopy), FESEM (Field emission scanning electron microscopy), EDS (Energy‐dispersive x‐ray spectroscopy), and XRD (x‐ray diffraction). Co3O4‐NPs as an efficient and practical catalyst was employed for the electrochemical oxidation of formaldehyde; which was an irreversible charge transfer controlled by mass transfer. The coefficients of electron transfer and diffusion were 0.87 and 0.122 cm2/s for formaldehyde oxidation on Co3O4 electrode, respectively. The formation of the CoOOH species during potential sweeping appears to be involved in the catalytic activity of the Co3O4 toward formaldehyde oxidation.