Rationally designed NiCo2S4/CoδSξ nanoflakes and redox-additive electrolyte: Boosting electrocatalytic activity

Designing and utilizing appropriate electrolytes in devices could prove to be an effective strategy to improve several electrocatalytic (OER) properties to yield high oxygen evolution reaction (OER) performance for their practical applications. Herein, synergistic effect of redox-additive electrolyte, K3[Fe(CN)6], on the catalytic performance vis-e-vis OER has been studied. By adopting this approach, the catalytic performance of NiCo2S4/CoδSξ nanoflakes, synthesized using pulse electrodeposition technique, has been enhanced. The addition of redox-active material in the electrolyte lowers the overpotential value to 383 mV with a Tafel slope of 83 mV/dec and boosts the diffusion coefficient value to 2.15 × 10−12 cm2/s with a high double layer capacitance value of 2.18 mF/cm2. Furthermore, the addition of redox-active material in electrolytes increases the electrochemically active surface area of the electrode and achieves a high stability of 100% after 2000 s of continuous evolution. This study paves the way to boost the OER performance of a catalyst by adding redox-active material in an electrolyte.