Synthesis and electrocatalytic oxygen evolution performances of Co₂Ni₁O₄/stainless steel composites

Electrolytic water includes hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), because OER is a complex 4-electron transfer process, developing highly active non-precious OER electrocatalysts with superior durability is crucial to electrolytic water. In order to reduce the cost, 304 stainless steel mesh (SS) was selected as the matrix, Co-Ni double hydroxides was prepared by electrodeposition, Co-Ni oxides were produced by vacuum calcination. The crystal structure, morphology and electrocatalytic OER performance of Co₂Ni₁O₄/ SS composite were studied by XRD, SEM, TEM, XPS and electrochemical workstation. As a result, the Co-Ni double hydroxides prepared by electrodeposition are transformed into Co-Ni oxides with spinel structure after vacuum calcination; successfully synthesized a large number of dense layered structures on the surface of stainless steel;the Co₂Ni₁O₄/SS electrode exhibits an outstanding OER catalytic activity with an overpotentials of 240 mV at 10 mA·cm⁻² and a Tafel slop as low as 53.92 mV·dec⁻¹ in 1.0 mol/L KOH. In addition, the Co₂Ni₁O₄/SS composites shows excellent stability in the alkaline electrolyte.