Phase-Controlled Synthesis of Nickel-Cobalt-Iron Sulfides By Electrodeposition for Efficient Oxygen Evolution Reaction

Abstract

Water electrolysis is an appealing and sustainable technology to produce clean hydrogen fuels to resolve the energy and environmental crisis. The development of highly efficient, stable, and cost-effective electrocatalysts for oxygen evolution reaction (OER) is crucial for future sustainable energy systems. In this work, the synthesis of nickel-cobalt-iron sulfides deposited on Ni foam (NiCoFeS@NF) was successfully realized via a facile electrodeposition method. It was found that the deposition potentials could affect the phase and nanostructures of nickel-cobalt-iron sulfides. The electrocatalyst NiCoFeS@NF was obtained by applying a deposition potential of -1.2 V (vs. Ag/AgCl), which exhibits superior OER activity in alkaline media with overpotentials of 309 mV and 370 mV to reach the current densities of 20 mA cm-2 and 50 mA cm-2, respectively. The high OER activity of NiCoFeS@NF is mainly attributed to the collaborative advantages of trimetallic sulfides and the porous conductive Ni foam as substrate. The introduce of iron to nickel-cobalt sulfides could generate more active sites for OER, and Ni foam can provide large area for active sites and facilitate the mass transport during the electrochemical process. This study highlights the importance of the construction of trimetallic sulfides with heterostructures, providing insights into the OER performance.