Facile Synthesis of Mesoporous Co3O4/CoO on rGO Nanocomposites as Highly Active and Stable Oxygen Bi-Functional Electrocatalysts

authors	Abidat, I; Ferreira, P; Napporn, TW; Rousseau, J; Guignard, N; Canaff, C; Morais, C; Habrioux, A; Kokoh, KB
nationality	International
journal	JOURNAL OF THE ELECTROCHEMICAL SOCIETY
keywords	GRAPHENE OXIDE; RAMAN-SPECTRA; EVOLUTION REACTION; COBALT OXIDE; REDUCTION; METAL; HYBRID; CATALYSTS; SPECTROSCOPY; FILMS
abstract	Mesoporous Co(3)O(4)mixed CoO onto reduced graphene oxide (rGO) nanocomposites were obtained by an easy surfactant-free synthesis using urea as hydrolyzing agent. This route enabled nanomaterials presenting tuned morphology, surface composition and oxide-rGO interactions as revealed by the different characterization techniques. Indeed, nanostructures varied from broom-like, chrysanthemum-like to micro-sized sheet-like morphologies. The amount of Co(3)O(4)phase was shown to be gradually rising as the urea amount increases being always higher at the surface than in the bulk. Different oxide-rGO interactions have also been demonstrated, suggesting that high amounts of urea cause a decrease in the size of the nanoparticles and limit their superposition. The catalysts prepared at high urea concentrations showed more exposed electroactive surface and enhanced activity as bifunctional oxygen electrocatalysts. Furthermore, the most active nanocomposite exhibited remarkable stability, making it a very promising candidate for the elaboration of a stable and truly reversible air electrode in alkaline media.
publisher	ELECTROCHEMICAL SOC INC
issn	0013-4651
isbn	1945-7111
year published	2020
volume	167
issue	13
digital object identifier (doi)	10.1149/1945-7111/abb8b4
web of science category	Electrochemistry; Materials Science, Coatings & Films
subject category	Electrochemistry; Materials Science
unique article identifier	WOS:000576084600001