Interfacial engineering of crystalline-amorphous NiCu-LDH/NiTe@NF: Opening a synergistic pathway for superior oxygen evolution catalysis

The design of an efficient oxygen evolution reaction (OER) catalyst is significant for water splitting. Telluride-based materials exhibit exceptional electrical conductivity and mass transfer properties, yet their application in electrocatalysis remains constrained by limited active site exposure. Conversely, layered double hydroxides possess unique granular/lamellar morphologies that offer significant potential for active site amplification through strategic morphology regulation. In response to the demand for highly efficient and stable OER electrocatalysts, this study presented a rationally designed heterostructure. NiTe nanorods were first grown on nickel foam (NF), followed by intimate coupling with granular nickel-copper layered double hydroxide (NiCu-LDH). Ultimately, a well-defined core-shell structure of NiCu-LDH/NiTe@NF was successfully constructed. Unlike conventional 2D nanosheets, the NiCu-LDH exhibited unique low-crystallinity characteristics, resulting in a crystalline-amorphous heterostructure that provided abundant unsaturated coordination sites, thereby effectively facilitating the adsorption and conversion of reaction intermediates. Benefiting from the optimized interfacial electronic structure and rapid charge transfer capability, the composite catalyst exhibited an overpotential of only 315 mV at a current density of 100 mA cm −2 and maintained stable operation for over 160 h at 50 mA cm −2 with negligible performance degradation. Mechanistic studies revealed that the formation of NiOOH acts as the true active species, significantly enhancing OER performance. This work not only offered a high-performance OER electrocatalyst, but also provided new insights into the rational design of crystalline-amorphous composite materials.