Doping fluoride into ternary FeCoNi hydroxide electrocatalysts to boost oxygen evolution reaction†

Abstract

Developing high-current oxygen evolution reaction (OER) electrocatalysts with low overpotential, high conductivity, high active surface area, and high stability is an attractive yet challenging process. Herein, a ternary FeCoNi hydroxide-fluoride material by doping fluoride into FeCoNi(OH)_x was synthesized through a simple electrodeposition method. The OER performance of FeCoNiF(OH)_x on a nickel foam electrode with a high surface area was associated with overpotentials of 243, 328, and 412 mV, with geometrical current densities of 100, 500, and 1000 mA cm⁻², respectively, in 1.0 M KOH solution. In addition, FeCoNiF(OH)_x exhibited high stability during controlled potential electrolysis in 1.0 M KOH at an overpotential of 243 mV for 50 h. Overall, we believe that our findings can advance the investigation of OER electrocatalysts.