Combined Corner-Sharing and Edge-Sharing Networks in Hybrid Nanocomposite with Unusual Lattice-Oxygen Activation for Efficient Water Oxidation

Corner-sharing and edge-sharing networks are the two most important material genomes. Inspired by the efficient electron transport capacity of corner-sharing structures and the low steric hindrance of edge-sharing units, an attempt is made to exert both merits by combining these two networks. Here, a unique self-assembled hybrid SrCo_0.55Fe_0.5O_3-δ nanorod composed of a corner-sharing SrCo_0.5Fe_0.5O_3-δ phase and edge-sharing Co₃O₄ structure is synthesized through a Co-site enrichment method, which exhibits the low overpotentials of 310 and 290 mV at 10 mA cm^–2 for oxygen-evolving reaction in 0.1 m and 1.0 m KOH, respectively. This efficiency is attributed to the high Co valence with strong Co-O covalence and the short distance between Co-Co/Fe metal active sites in hybrid nanorods, realizing a synergistic benefit. Combined multiple operando/ex situ characterizations and computational studies show that the edge-sharing units in hybrid nanorods can help facilitate the deprotonation step of lattice oxygen mechanism (LOM) while the corner-sharing motifs can accelerate the electron transport during LOM processes, triggering an unusual lattice-oxygen activation. This methodology of combining important material structural genomes can offer meaningful insights and guidance for various catalytic applications.