Enhancing the stability of NiFe-layered double hydroxide nanosheet array for alkaline seawater oxidation by Ce doping

Abstract

Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation. Nevertheless, the direct electrolysis of seawater encounters significant challenges due to poor anodic stability caused by detrimental chlorine chemistry. Herein, we present our recent discovery that the incorporation of Ce into NiFe layered double hydroxide nanosheet array on Ni foam (Ce-NiFe LDH/NF) emerges as a robust electrocatalyst for seawater oxidation. During the seawater oxidation process, CeO2 is generated, effectively repelling Cl− and inhibiting the formation of ClO−, resulting in a notable enhancement in the oxidation activity and stability of alkaline seawater. The prepared Ce-NiFe LDH/NF requires only overpotential of 390 mV to achieve the current density of 1 A cm−2, while maintaining long-term stability for 500 h, outperforming the performance of NiFe LDH/NF (430 mV, 150 h) by a significant margin. This study highlights the effectiveness of a Ce-doping strategy in augmenting the activity and stability of materials based on NiFe LDH in seawater electrolysis for oxygen evolution.