Interfacial electronic coupling and dynamic surface restructuring of Co2P/NixTey heterojunction for enhanced overall water splitting

Interfacial electronic coupling and dynamic surface restructuring are key to enhancing the performance of Co 2 P bifunctional electrocatalysts; however, the role of heterointerfaces in regulating anode restructuring remains unclear. Here, a flower-like Co 2 P/Ni x Te y /NF nanoarray rich in heterointerfaces was constructed by coupling Co 2 P with hydrothermally grown Ni x Te y /NF. This structure exposes abundant active sites, accelerates charge transfer, and promotes anodic reconstruction toward Ni/CoOOH active species, which contributes to the enhanced activity. In 1.0 M KOH, Co 2 P/Ni x Te y /NF electrode requires overpotential of only 66/108 mV to achieve 10 mA cm −2 for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), respectively. A two-electrode electrolyzer assembled with Co 2 P/Ni x Te y /NF achieves 10 mA cm −2  at 1.52 V and sustains 100 mA cm −2 for over 1000 h. In-situ Raman spectroscopy directly reveals potential-driven surface reconstruction to Ni/CoOOH, while Laviron analysis indicates accelerated electron-transfer kinetics for the metal-center oxidation, providing guidance for designing dynamically evolving non-precious electrocatalysts.