Ce-anchored NiFeOOH derived from in-situ self-optimization for efficient and highly durable water oxidation

Metal-organic frameworks could undergo surface reconstruction to form (oxy)hydroxide which is regarded as a real active species during the electrolysis. However, it is still a challenge to manipulate the reconstruction process to achieve the highly active (oxy)hydroxide species. Herein, a viable Ce decoration strategy is developed to optimize the structural reconstruction of NiFe-MIL-53 and enhance the activity of reconstructed species. Theoretical and experimental investigations suggest that the unique 4f valence electron structure of Ce atoms induces charge redistribution through strong 3d-2p-4f orbital electron coupling. This promotes the interface charge transfer, optimizes the adsorption of oxygen-containing intermediates, and reduces the energy barrier, thus enhancing oxygen evolution reaction (OER) performance. Consequently, the reconstructed Ce@NiFeOOH requires a low overpotential of 219 mV at 10 mA cm−2 with a small Tafel slope of 28.1 mV dec-1. Additionally, Ce@NiFeOOH is also operated for 1780 h at 10/100 mA cm−2 without noticeable attenuation, demonstrating excellent long-term durability. This study offers a promising strategy for the construction of outstanding performance electrocatalysts