Carbon Quantum Dot/NiFe Layered Double-Hydroxide Composite as a Highly Efficient Electrocatalyst for Water Oxidation

The design of highly efficient, durable, and earth-abundant catalysts for the oxygen evolution reaction is crucial to a variety of important energy conversion and storage processes. Here, we use carbon quantum dots (CQDs, ∼5 nm) to form hybrids with the ultrathin nickel–iron layered double-hydroxide (NiFe-LDH) nanoplates. The resulting CQD/NiFe-LDH complex exhibits high electrocatalytic activity (with an overpotential of ∼235 mV in 1 M KOH at a current density of 10 mA cm^–2) and stability for oxygen evolution, which almost exceed the values of all previously reported Ni-Fe compounds and were comparable to those of the most active perovskite-based catalyst