Graphene‐Assisted Co‐Ni Bimetallic ZIF as an Efficient Composite Catalyst for Enhanced Oxygen Evolution Reaction Activity at High Current Densities

The development of efficient and stable electrocatalysts for the oxygen evolution reaction (OER) under high current densities is critical for industrial‐scale sustainable energy conversion. In this article, a series of graphene‐modified Co‐Ni bimetallic zeolitic imidazolate framework (ZIF‐67) composites with varying Co/Ni molar ratios (10:1, 10:3, 10:5, 10:8, 10:10, denoted as ZIF‐67(R1)/GO to ZIF‐67(R10)/GO) were in situ grown on nickel foam via chemical deposition. The deliberate introduction of graphene and Ni doping synergistically addressed the key limitations of pristine ZIF‐67, thereby enabling exceptional OER performance at high current densities. The optimized ZIF‐67(R5)/GO catalyst exhibited outstanding OER activity, requiring only a low overpotential of 255 mV to reach 100 mA cm ⁻² , and maintained 90.6% of its initial current density after 25 h of continuous operation at 100 mA cm ⁻² in 1.0 M KOH.