Hydrothermal synthesis of carbon nanotube/cubic Fe3O4 nanocomposite for enhanced performance supercapacitor electrode material

Graphical abstract: First, the acid treated CNTs were used as support substrate. Then cubic Fe3O4 nanoparticles directly anchored on the surfaces of CNTs as supercapacitor electrode material by an easy and cost effective hydrothermal method. Results showed that the composite has superior capacitive performance with a maximum specific capacitance of 119 F/g. -- Highlights: • The acid treated CNTs were used as conductive substrate materials. • Cubic Fe3O4 nanoparticles directly grew onto surfaces of CNTs preventing the agglomeration of Fe3O4. • The loose structure improves the contact between the electrode and the electrolyte. • Results showed that this composite has good electrochemical property. -- Abstract: Carbon nanotube/Fe3O4 (CNT/Fe3O4) nanocomposite with well-dispersed Fe3O4 nano-cubes inlaid on the surfaces of carbon nanotubes, was synthesized through an easy and efficient hydrothermal method. The electrochemical behaviors of the nanocomposite were analyzed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronopotentiometry in 6 M KOH electrolyte. Results demonstrated that CNT as the supporting material could significantly improve the supercapacitor (SC) performance of the CNT/Fe3O4 composite. Comparing with pure Fe3O4, the resulting composite exhibited improved specific capacitances of 117.2 F/g at 10 mA/cm2 (3 times than that of pure Fe3O4), excellent cyclic stability and a maximum energy density of 16.2 Wh/kg. The much improved electrochemical performances could be attributed to the good conductivity of CNTs as well as the anchored Fe3O4 particles on the CNTs