Directional regulating dynamic equilibrium to continuously update electrocatalytic interface for oxygen evolution reaction

The construction of a stable catalytic interface is the key step of heterogeneous catalysis for water splitting. However, it is very difficult to controllably regulate the performances of dynamic interfaces especially for industrial application. Based on this, we found that FeOOH-transformation equilibrium and the Fe* adsorption-dissolution equilibrium could be regulated simultaneously to achieve the continuous update of the catalytic interface by changing the Fe3+ concentration in alkaline electrolyte. FeOOH-Ni-based oxygen evolution catalysts with high activity and long-term stability can be synthesized by in-situ electro-activation and directional regulation of catalytic equilibrium. Moreover, this strategy is suitable for almost all nickel-based materials, including Ni-MOF, Ni2P, Ni3S2, Ni(OH)2, NiO. Among them, FeOOH-NiBDC-NF shows excellent activity for OER: when the current density reached 100 mA cm−2 and 500 mA cm−2, the overpotential is only 278 mV and 316 mV, respectively. Interestingly, the active catalytic interface can be updated in situ by directional adjustment of dynamic equilibrium, which can conveniently maintain the activity and stability of the catalysts. Finally, after testing at a large current density of 500 mA cm−2 for 100 h, FeOOH-NiBDC-NF still maintained excellent performance. This study shows that the strategy of directionally regulating ion equilibrium at the dynamic interface is effective.