A simple microwave process for the preparation of cobalt oxide nanoparticles supported on carbon nanotubes for electrocatalytic applications

Cobalt oxide nanoparticles supported on multiwalled carbon nanotubes (CoOx/CNTs) were prepared by a facile and rapid solid-state synthesis using microwave irradiation. Thermal decomposition of a cobalt precursor under microwave irradiation leads to the formation of oxides of cobalt in the nanoparticle range (mainly 10–15 nm). X-ray diffraction reveals the existence of crystalline CoO and Co 3 O 4 . CoOx/CNTs show superior electrochemical activity towards oxygen reduction reaction (ORR) in alkaline media with a near 4-electron transfer. Initial electrochemical stability tests of the CoOx/CNTs for ORR in alkaline solution under potentiostatic conditions show ~ 88% retention in performance after continuous operation for 6 h. The results on activity and stability of CoOx/CNT catalysts demonstrate that this facile and rapid synthesis might pave the way to a quick and cheap preparation of catalysts for applications in electrochemical energy conversion.