Boosting Superior Electrocatalytic OER Performance through Synergistic Effect of Fe-Doping and Lattice Oxygen Activation in Ni(OH)₂/GO

The oxygen evolution reaction (OER), a key component of water splitting, is considered a promising technology for large-scale energy storage. Nevertheless, the sluggish kinetics and high costs of precious metal-based electrocatalysts like RuO 2 and IrO 2 limit its applications. This work focuses on developing non-precious metal-based electrocatalysts with low overpotential, high current density, and durability. Ni(OH) 2 /GO and NiFe(OH) x /GO composites were successfully synthesized via a straightforward one-step solvothermal technique. The NiFe(OH) x /GO composite exhibits uniform growth and distribution of NiFe(OH) x onto GO sheets, and a high specific surface area of 123.6 m 2 g −1 , leading to superior OER activity with an overpotential of 250 mV at j = 10 mA cm −2 . This represents a significant improvement over pure Ni(OH) 2 (320 mV) and IrO 2 (368 mV). NiFe(OH) x /GO also demonstrates good electrochemical stability, maintaining nearly unchanged current density for more than 48 h. Furthermore, validation experiments and density functional theory calculations reveal that the lattice-oxygen-mediated mechanism, instead of the traditional absorbate evolution mechanism, plays a crucial role in the OER process for both Ni(OH) 2 /GO and NiFe(OH) x /GO composites. Overall, our findings highlight NiFe(OH) x /GO as a promising candidate for efficient and cost-effective OER electrocatalysts.