Dynamic Reconstructed RuO 2 /NiFeOOH with Coherent Interface for Efficient Seawater Oxidation.

Developing efficient oxygen evolution reaction (OER) electrocatalysts for seawater electrolysis is still a big challenge. Herein, a facile one-pot approach is reported to synthesize RuO 2 -incorporated NiFe-metal organic framework (RuO 2 /NiFe-MOF) with unique nanobrick-nanosheet heterostructure as precatalyst. Driven by electric field, the RuO 2 /NiFe-MOF dynamically reconstructs into RuO 2 nanoparticles-anchored NiFe oxy/hydroxide nanosheets (RuO 2 /NiFeOOH) with coherent interface, during which the dissolution and redeposition of RuO 2 are witnessed. Owing to the synergistic interaction between RuO 2 and NiFeOOH, the as-reconstructed RuO 2 /NiFeOOH exhibits outstanding alkaline OER activity with an ultralow overpotential of 187.6 mV at 10 mA cm -2 and a small Tafel slope of 31.9 mV dec -1 and excellent durability at high current densities of 840 and 1040 mA cm -2 in 1 m potassium hydroxide (KOH). When evaluated for seawater oxidation, the RuO 2 /NiFeOOH only needs a low overpotential of 326.2 mV to achieve 500 mA cm -2 and can continuously catalyze OER at 500 mA cm -2 for 100 h with negligible activity degradation. Density function theory calculations reveal that the presence of strong interaction and enhanced charge transfer along the coherent interface between RuO 2 and NiFeOOH ensures improved OER activity and stability.