Electrocatalytic activity of CoFe2O4 thin films prepared by AACVD towards the oxygen evolution reaction in alkaline media

© 2017 The Authors The electrocatalytic behaviour of CoFe 2 O 4 thin films, prepared by aerosol-assisted chemical vapour deposition, towards the oxygen evolution reaction in an alkaline medium is reported. X-ray diffraction and SEM data show that the CoFe 2 O 4 thin films are phase pure and consist of dendrites 0.5–1 μm in diameter rising from the surface with heights ranging from 1 to 3 μm. The CoFe 2 O 4 thin films exhibited an overpotential of 490 mV at a current density of 10 mA cm − 2 , and a Tafel slope of 54.2 mV dec − 1 . Taking into account the electrochemically active surface area, the intrinsic activity of CoFe 2 O 4 was found to be 1.75 mA cm − 2 real at an overpotential of 490 mV. The CoFe 2 O 4 thin films were highly stable and were capable of maintaining catalytic activity for at least 12 h