In Situ Antisolvent Approach to Hydrangea-like HCo₃ O₄ -NC@CoNi-LDH Core@Shell Superstructures for Highly Efficient...

Highly active, durable, and cost-effective electrocatalysts for water oxidation are at the center of renewable energy technologies. However, the development of water oxidation catalysts with high activity at low cost remains a great challenge. Herein, an in situ antisolvent approach is reported for synthesizing ultrathin Co-Ni layered double hydroxide (CoNi-LDH) nanosheets wrapped on hollow Co₃ O₄ nanoparticle-embedded nitrogen-doped carbon (HCo₃ O₄ -NC) as a high-performance catalyst for the oxygen evolution reaction (OER). Although HCo₃ O₄ -NC or NiCo-LDH alone has little OER activity, their hybrid exhibits low overpotential and Tafel slope as well as high stability, due to the synergistic effect of Co₃ O₄ and LDH. Furthermore, the hydrangea-like HCo₃ O₄ -NC@NiCo-LDH core@shell composite exhibits higher catalytic activity and stability than commercial IrO₂ , which makes it a high-performance nonprecious-metal-based catalyst for OER.