In situ semi-sacrificial template-assisted growth of ultrathin metal-organic framework nanosheets for electrocatalytic oxygen evolution

Ultrathin Bimetal MOF nanosheets (BMOFNs) are regarded as effective electrocatalyst for Oxygen evolution reaction (OER) because of their abundance of coordinatively unsaturated metal atoms, enhanced mass permeability and coupling effect between bimetals, while the limited conductivity and stability severely hinders their widespread application. Here, we develop an in situ semi-sacrificial template-assisted strategy to grow ultrathin BMOFNs on NiCo-LDH to construct non-noble metal electrocatalysts that are both active and stable. The optimized NiCo-LDH@MOFs heterostructure exhibits a superior electrocatalytic activity with accelerated electronic transfer and significantly enhanced durability of over 300 h. An advanced AFM-IR technology is introduced for the first time to investigate the formation of the 2D-2D heterogeneous structure in NiCo-LDH@MOFs, providing insights into the morphology-structure-composition evolution of the electrocatalyst at a nanoscale. This work demonstrates an in-situ growth strategy to achieve high-performance ultrathin MOF-based electrocatalysts, and provides advanced combinatorial characterization techniques to monitor the material growth process.