Electrochemistry assisted chlorine corrosion strategy: The minute-level fabrication of lattice Cl– functioned high spin-polarized Ni/Fe-LDH array for enhanced anti-Cl– OER performance

Abstract

Although the intermittent energy-driven direct seawater splitting technology provides an unparalleled approach to achieving sustainable development, the severe corrosion via aggressive Cl^– severely affects the stability and efficiency of the anode catalyst and limits its industrial application. Herein, a lattice Cl^– functioned NiFe-LDH electrode (E-NF-LDH_Cl or E-NF-LDH_SW) is firstly constructed by a minute-level electrochemistry assisted chlorine corrosion strategy, which presents enhanced oxygen evolution reaction (OER) performance and excellent anti-Cl^– corrosion behavior for seawater splitting. The optimized E-NF-LDH_Cl and E-NF-LDH_SW deliver low OER overpotential of 355 and 384 mV to reach 1 A cm⁻² current density in the 1 mol L^–1 KOH and 1 mol L^–1 KOH seawater, respectively, as well as excellent stability of E-NF-LDH_Cl is maintained at 1 A cm^–2 for 400 h in the 1 mol L^–1 KOH and 1 mol L^–1 KOH + 0.5 mol L^–1 NaCl. MD (molecular dynamics) simulation and DFT (density functional theory) calculation confirmed that strong common-ion repulsion effect in IHP region repels free Cl^–, forming high spin polarization centers and more single electrons to enhance the intrinsic activity of OER.