A Ni(OH)2 nanosheet array modified with Fe–phytate complex layer as a corrosion resistant catalyst for seawater electrolysis at ampere-level current density

Abstract

The implementation of electrochemical seawater electrolysis necessitates the development of electrocatalysts that not only exhibit high performance but also possess robust resistance to chlorine-induced corrosion. Herein, we report a Ni(OH)₂ nanosheet array modified with an Fe–phytate complex layer through a straightforward spray technique for high activity and strong corrosion resistance toward seawater electrolysis. The constructed Ni(OH)₂–PA–Fe requires an overpotential of merely 380 mV at a current density of 1000 mA cm⁻² and exhibits extraordinary stability in alkaline seawater, maintaining stable performance for over 1200 hours at a current density of 1000 mA cm⁻². Experimental analyses reveal that the exceptional OER performance stems from the increased number of active sites due to defect formation, electronic structure modulation by iron phytate modification, and Cl⁻-repellent layers formed by negatively charged phosphate groups on the electrocatalyst surface. This work offers new possibilities and a cost-effective approach for developing highly efficient catalysts with enhanced corrosion resistance for seawater electrolysis.