Rapid synthesis of Fe doped NixP/reduced graphene oxide for enhanced oxygen evolution reaction activity in alkaline freshwater and seawater

Abstract

The development of highly active and selective oxygen evolution reaction (OER) electrocatalysts for electrocatalytic seawater splitting is essential for efficient hydrogen production. Triggering the involvement of lattice oxygen represents an efficient approach for designing highly active OER electrocatalysts as it can bypass the intrinsic limitations associated with the adsorbate evolution mechanism, though significant challenges remain. Herein, we present the synthesis of a highly active OER electrocatalyst, reduced graphene oxide supported Fe-doped nickel phosphide (Fe-Ni_xP/RGO-M), which follows the lattice oxygen mechanism (LOM) and exhibits excellent performance in seawater splitting through a novel microwave-assisted strategy. Electrochemical measurements and theoretical calculation results demonstrate that introducing Fe can promote structural reconstruction and reinforce the participation of lattice oxygen. Furthermore, employing a microwave-assisted strategy can significantly improve resistance against chloride corrosion compared with conventional high-temperature treatment methods. Consequently, the optimized Fe-Ni_xP/RGO-M exhibits superior OER activity with low overpotentials of 299 and 349 mV at 1000 mA cm⁻² in alkaline freshwater/seawater, respectively. This work offers a facile approach and valuable insight for developing high-performance LOM-based OER electrocatalysts for freshwater/seawater splitting.