Anchoring cobalt oxide nanoparticles on to the surface multiwalled carbon nanotubes for improved supercapacitive performances

The present work explored a novel, simple and low cost 'dipping and drying' process followed by a successive ionic layer adsorption and reaction (SILAR) method for the synthesis of cobalt oxide anchored multiwalled carbon nanotubes (Co3O4/MWNTs). Initially, MWNTs have been coated on a stainless steel substrate by a simple 'dip and dry' method, on which further deposition of cobalt oxide nanoparticles was carried out by the SILAR method. Our results confirm the uniform coating of Co3O4 nanoparticles having sizes less than 15 nm on the surface of MWNTs. Later, the electrochemical performance shows that, the Co3O4/MWNTs films exhibit a maximum specific capacitance of 685 F g(-1) in a 2 M KOH electrolyte at a scan rate of 5 mV s(-1) with high cycle stability of 73% over 5000 cycles. Moreover, lower electrochemical equivalent series resistance (11.25 m Omega) give rise to the superior performance. These results show, the potential of Co3O4/MWNTs composite electrodes in electrochemical supercapacitors.