Hydrothermally grown Ni0.7Zn0.3O directly on carbon fiber paper substrate as an electrode material for energy storage applications

• Hydrothermal synthesis of Ni0.7Zn0.3O mixed oxide on the carbon fiber paper.
• Nanostructured Ni0.7Zn0.3O film composed of nanonet.
• Mixed oxide electrodes showed high specific capacitance of 770 F g−1 at 1 A g−1 and very good cycling stability in 2 M KOH.

Nickel oxides because of their excellent electrochemical performance have been considered attractive materials for electrochemical energy storage. However, their application as active material for redox supercapacitor electrodes has been limited by poor electrical conductivity. In order to improve this property, herein we synthesized a nanonet of NiZn-mixed oxide, by facile hydrothermal route, directly on the substrate. The Zn-modified oxide material showed good electrochemical performance, displaying specific capacitance of 770 F g−1 at 1 A g−1 and almost 120% capacitance retention after 2000 cycles of charge discharge at 2 A g−1 in 2 M KOH. Electrochemical impedance results revealed that the Ni0.7Zn0.3O mixed oxide displayed increased conductivity compared to the single NiO material.