Promotion effect of intercalated citrate anion on the reconstruction of NiFe LDH for oxygen evolution reaction

The reconstruction of pre-catalysts is a powerful strategy to achieve efficient oxygen evolution reaction (OER) electrocatalysts under alkaline conditions. Herein, NiFe based layered double hydroxides (LDHs) intercalated with citrate anions (CA) are constructed as pre-catalysts via a one-pot hydrothermal method. The CA intercalation exhibits an obvious promotion effect on structure reconstruction, which improves the OER performance. Benefiting from promoted structure reconstruction, a low overpotential of 241 mV at 50 mA cm-2, and an ultralow Tafel slope of 36.4 mV dec-1 can be achieved with robust durability (over 82 h at 50 mA cm-2), demonstrating better OER performance than that of NiFe LDH without CA intercalation. The addition of CA into the electrolyte could enhance the OER activity, indicating surface-adsorbed CA promotes the OER activity of NiFe LDHs. Our findings provide new insight into the effect of anions on catalyst reconstruction and provide a new way of developing efficient electrocatalysts. The promotion effect of citrate anions (CA) on OER activity is considered. CA intercalation could accelerate the structure reconstruction to re-form the catalytically active Ni(Fe)OOH.