Cobalt-regulated NiFe-LDH for efficient electrocatalytic oxygen evolution in alkaline simulated industrial sewage and natural seawater

The electrolysis of alkaline industrial sewage and seawater to produce hydrogen can alleviate the freshwater problem while also achieving clean energy production. Herein, we developed a three-dimensional spherical NiCoFe-LDH electrocatalyst for electrocatalytic oxygen evolution reaction (OER) by ions exchange and co-precipitate. The electronic interaction between the polymetallic ions optimizes the adsorption and desorption of the oxygen-containing intermediates. Compared to NiFe-LDH, the introduction of Co promoted the adsorption of OH* and the deprotonation of OOH* adsorbate intermediates. The prepared electrocatalyst shows good OER activity with a overpotential of 274 mV at 10 mA/cm2. Furthermore, the prepared electrocatalysts exhibit good resistance to chloride ion corrosion, and the industrial-grade geometric current density of 500 mA/cm2 could be achieved at a potential of approximately 1.68 V (vs. RHE) in strongly alkaline (6 M KOH) industrial sewage and seawater.