Self-assembled Ni2P nanosheet-implanted reduced graphene oxide composite as highly efficient electrocatalyst for oxygen evolution reaction

Abstract

Hydrogen generation from electrocatalytic water splitting is one of the promising methods to gain clean and sustainable energy. As a semi-reaction in the electrochemical reaction of water splitting, the oxygen evolution reaction (OER) has limited the development and practical application of water electrolysis technology due to its slow kinetic speed and high overpotential. Through different doping options, defect engineering, and interface coupling effects, the activity of the catalyst can be improved. By using low-priced transition metals, composites such as iron-based, cobalt-based and nickel-based phosphorus-doped or nitrogen-sulfur doped composite materials are designed and synthesized to achieve large overpotentials and current densities, thus the performance could be improved. In this work, the synthesis of Ni2P/rGO nano-hybrids by phosphating Ni(OH)2/rGO precursors at low temperature was investigated. It is worth noting that the synthesized Ni2P/rGO hybrid can be used as an OER catalyst under alkaline conditions and remains active for more than 12 h. It has an initial potential at 221 mV and the Tafel slope is 105.7 mV/dec. Present research works provide new ideas for the preparation of alternative precious metal electrocatalysts used for OER.