Poly[(2-methacryloyloxy)Ethyl]Trimethylammonium Chloride Supported Cobalt Oxide Nanoparticles as an Active Electrocatalyst for Efficient Oxygen Evolution Reaction.

Abstract

To combat with energy crisis considering clean energy, oxygen evolution reaction (OER) is crucial to implement electrolytic hydrogen fuel production in real life. Here, straightforward chemical synthesis pathways are followed to prepare cobalt tetraoxide nanoparticles (Co3O4NPs) in an alkaline OER process using poly[(2-methacryloyloxy)ethyl]trimethylammonium chloride (Co3O4NPs@PMTC) as support to prevent aggregation. In material characterization, the X-ray diffraction (XRD) pattern confirms the crystallinity of the synthesized Co3O4NPs@PMTC, and Raman spectroscopy indicates that the Co3O4NPs contain cubic close-packed oxides. The morphological analysis reveals the wrinkle-like disruption which is distributed evenly owing to the folded nanosheet arrays. Energy-dispersive X-ray spectroscopy indicates the presence of a significant number of cobalt atoms in the Co3O4NPs, and elemental mapping analysis demonstrates the composition of the NPs. At a current density of 10 mA cm-2, oxygen is emitted at 1.67 V delivering an overpotential of 440 mV. This unique structure of Co3O4NPs@PMTC provides beneficial functions that are responsible for a large number of active sites and the rapid release of oxygen gas with long-term stability. Through kinetic study, we found a Tafel slope of 48.9 mV dec-1 which proves the catalytic behavior of Co3O4NPs@PMTC is promising toward the OER process.