Binary cobalt ferrite nanomesh arrays as the advanced binder-free electrode for applications in oxygen evolution reaction and supercapacitors

Abstract

Abstract The porous CoFe 2 O 4 nanomesh arrays are successfully synthesized on nickel foam substrate through a high temperature and pressure hydrothermal method, following by the thermal post-treatment in air. The CoFe 2 O 4 nanomesh arrays own numerous pores and large specific surface area, which is in favor of exposing more active sites. In consideration of the structural preponderances and versatility of the materials, the CoFe 2 O 4 nanomesh arrays have been researched as the binder-free electrode materials for electrocatalysis and supercapacitors. When the CoFe 2 O 4 nanomesh arrays on nickel foam (CoFe 2 O 4 NM-As/Ni) directly act as the free-binder catalyst toward catalyzing the oxygen evolution reaction (OER) of electrochemical water splitting, CoFe 2 O 4 NM-As/Ni exhibits an admirable OER property with a low onset potential of 1.47 V(corresponding to the onset overpotential of 240 mV), a minimal overpotential ( η 10 = 253 mV), a small Tafel slope (44 mV dec −1 ), large anodic currents and long-term durability for 35 h in alkaline media. In addition, as an electrode of supercapacitors, CoFe 2 O 4 NM-As/Ni obtains a desired specific capacitance (1426 F/g at the current density of 1 A/g), remarkable rate capability (1024 F/g at the current density of 20 A/g) and eminent capacitance retention (92.6% after 3000 cycles). The above results demonstrate the CoFe 2 O 4 NM-As/Ni possesses great potential application in electrocatalysis and supercapacitors.