Cu-induced electronic redistribution of pine needle/nanosheet hybrid Cu-P-Co ternary catalyst toward efficient...

The development of efficient alkaline water electrolysis catalysts remains challenged by sluggish hydrogen evolution kinetics and insufficient active sites. Herein, a Cu-P-Co ternary electrocatalyst with pine-needle-like nanorod/nanosheet hybrid architecture is fabricated on nickel foam (Cu-P-Co/NF) via one-step electrodeposition. The introduction of Cu and P elements enables the formation of a well-defined Cu₃P nanorod / Co₂P nanosheet heterostructure. This unique hybrid architecture provides a vast number of accessible electrochemical active sites. Crucially, the advanced density functional theory (DFT) simulations elucidate that the established Cu₃P@Co₂P heterointerface drives substantial interfacial charge redistribution. This interfacial electronic interaction effectively modulates the local electronic structure of the Co sites, specifically inducing a downshift in the d-band center, which optimizes the hydrogen desorption free energy (ΔG_H^⁎). More importantly, this electronic modulation directly optimizes the H₂O adsorption free energy on the Co active centers, thereby significantly boosting their intrinsic HER activity in alkaline media. The Cu-P-Co/NF achieves an ultralow overpotential of 70 mV at 10 mA cm^-2 in alkaline media, outperforming most reported Co-based electrocatalysts. This work demonstrates dual regulation of nanostructure engineering and electronic modulation under the ternary synergy through experimental coupling theory simulation calculation, providing a rational design paradigm for high-performance electrocatalysts.