Zr-doped heterostructure interface to tune the electronic structure of bi-functional electrocatalysts for water splitting†

Electrocatalysts with earth-abundant materials for water splitting are proposed to obtain high activity and durability simultaneously by Zr-doping interface based on physical chemistry and material science for engineering applications. Here, we report a high-valence Zr metal doping-based technique to design Zr-NiFeLDH@NiCoP/NF 3D heterostructure bi-functional electrocatalysts. This approach effectively regulates the electronic structure and surface catalytic morphology; thus the incorporation of high-valence Zr significantly enhances reaction kinetics, as evidenced by the Tafel plot and electrochemical impedance spectroscopy. The electrocatalysts enriched the active sites and achieved low overpotentials, as a result of comparable performance and impressive long-term stability exceeding 100 h at a high current density of 500 mA m⁻² for both HER and OER. Furthermore, Zr-NiFeLDH@NiCoP/NF exhibits exceptional overall water splitting performance, requiring only 1.53 V to reach 10 mA cm⁻² and showcasing remarkable durability for 865 h as an anode and cathode. Therefore, this work demonstrates the promising potential of integrating nonprecious high-valence Zr metal into Zr-NiFeLDH@NiCoP/NF heterostructure bi-functional electrocatalysts to significantly enhance overall water splitting performance.