Pulse-electrodeposited Cr/Fe-Ni(OH)2 on nickel felt for scalable fabrication of highly-efficient and stable anode in seawater splitting

Abstract

For electrocatalytic anodes applied in seawater splitting, it should be not only highly efficient, but also resistant to chloride ions’ corrosion. Herein, a pulse electrodeposition method has been applied to fabricate NiFeCr-based catalysts on nickel felt. Element of Cr, acting as a Lewis acid site, locally enriches OH⁻ ions, thereby enhancing chloride corrosion resistance while regulating the electronic structure of adjacent nickel/iron sites. As a result, as-prepared anode is achieved a low overpotential of 203.8 mV at a current density of 10 mA cm-2. Moreover, this preparation method can be scalable production of the anode. A 4 cm × 4 cm anode assembled into an anion-exchange membrane electrolyzer achieved a current density of 1000 mA cm-2 at a low cell voltage of 1.837 V. Overall, this work provided a feasible method to prepare large-scale anode with highly-efficiently activity and highly resistant to Cl-in seater splitting.