Synergistic effect of Ce doping and heterointerface engineering of NiCoP/Ce-NiCo LDH for durable and corrosion-resistant electrocatalysis in alkaline freshwater and seawater oxidation

Abstract

Hydrogen production via seawater electrolysis is regarded as a promising avenue for utilizing sustainable energy. However, developing an efficient electrocatalyst with low overpotential and high chloride corrosion resistance remains a considerable challenge. In this research, a heterostructure NiCoP/Ce-NiCo LDH catalyst was fabricated by a simple hydrothermal-phosphorization-electrodeposition method. This catalyst features Ce-doped NiCo LDH nanosheets covering NiCoP nanoarrays. During seawater oxidation, the generated PO₄³⁻ effectively inhibits ClO⁻ formation. The NiCoP/Ce-NiCo LDH catalyst delivers a current density of 100 mA cm⁻² with overpotentials of only 258 and 272 mV in alkaline freshwater and seawater, respectively. It also exhibits exceptional stability, maintaining a current density of 100 mA cm⁻² for 100 h in both alkaline freshwater and seawater. DFT calculations indicate that Ce doping and the heterostructure formation in NiCoP/Ce-NiCo LDH optimize the electronic structure of the catalyst and reduce the energy barrier of rate-determining step, synergistically enhancing OER performance. This study demonstrates a promising strategy for developing durable and highly active catalytic materials for seawater electrolysis.