Plasma-Assisted Nitrogen-Doped NiHf Nanoalloy for Efficient Seawater Electrolysis

Abstract

Hydrogen production through seawater electrolysis has gained increasing attention, yet it faces significant challenges, including cathode poisoning by impurities and severe chloride (Cl-) corrosion. Herein, a plasma-assisted nitrogen-doped alloying strategy was developed to enable the in-situ growth of nitrogen-doped NiHf nanoalloy catalysts on processed nickel foam substrates(N-NiHf@NF) catalysts for hydrogen evolution reaction (HER). This approach combines abundant resource availability, high electrical conductivity, and exceptional corrosion resistance, making it highly promising candidates for seawater electrolysis. Nitrogen doping effectively modulates the electronic environment of the metal nanoalloys, enabling highly efficient and corrosion-resistant hydrogen evolution. Compared to undoped another NiHf nanoalloy catalysts, the N-NiHf@NF electrocatalysts exhibit enhanced intrinsic HER performance, achieving a low overpotential of 68 mV at 10 mA cm-2 in alkaline seawater electrolyte. This enhanced performance primarily stems from the synergistic effect between nitrogen dopants and the nanoalloy matrix. Furthermore, N-NiHf@NF demonstrates exceptional electrochemical stability and corrosion resistance. Structural and elemental analyses confirm that the catalyst maintains its original architecture even after prolonged HER testing. The corrosion resistance mechanism is systematically investigated through electrochemical methods. Potentiodynamic polarization and stability tests reveal outstanding long-term durability and chloride corrosion resistance. This work highlights the great potential of nitrogen-doped NiHf nanoalloy catalysts for seawater electrolysis and provides new insights into surface modification strategies for nanoalloy-based electrocatalysts.