Lina Zhang, Fang Tian, C. C. Liu, W W Wang, Shiying Wang, Zhidong Chen
This study reports a dual composition-interface engineering strategy for high-performance La1−xSrxCoO3/NiFe-LDH hierarchical heterojunction. Porous La1−xSrxCoO3 microspheres were synthesized through a gel route. Then it was used as an in situ–formed template to grow NiFe-LDH nanosheets. The hierarchical design inhibits nanosheet aggregation and ensures robust interfacial contact, mitigating the intrinsic instability of physical mixtures. The prepared composite displays superior OER performance in 1.0 M KOH, delivering an overpotential of 237.8 mV at 10 mA cm−2 and a Tafel slope of 85.06 mV dec−1. These values exceed those of the original samples and commercial RuO2 and the composite exhibits excellent long-term stability under harsh alkaline conditions. Complemented by DFT calculations, we further indicate that Sr doping coupled with the heterointerface induces substantial electronic structure reconstruction. This effectively switches the OER mechanism from conventional AEM to the thermodynamically more favorable LOM, overcoming the intrinsic scaling relation constraints of AEM.