Ni Nanoparticles Encapsulated in NiS/N-CNT as Advanced Electrocatalysts for Oxygen Evolution Reaction

The primary limitations of the oxygen evolution reaction (OER) electrocatalysts stem from poor electrical conductivity and insufficient accessibility of active sites. So highly productive catalysts are vital to lower the overpotential and enhance the kinetics of the sluggish OER. In this work, we present an effective OER electrocatalyst (NiS/N-CNT@Ni) and composites of Ni nanoparticles encapsulated in NiS/N-CNT fabricated via a simple two-step thermal treatment method. Meanwhile, due to the synergistic effect between NiS and nitrogen-doped carbon nanotubes (CNTs) and Ni, the NiS/N-CNT@Ni composites show higher OER electrocatalytic activity and better durability than commercial RuO 2 catalysts. Compared to commercial RuO 2 , the NiS/N-CNT@Ni catalyst demonstrates a lower overpotential (313 mV at 10 mA cm −2 ) and better stability. This study confirms that the NiS/N-CNT@Ni material not only exhibits a low overpotential but also presents a scalable, cost-effective synthesis strategy for high-performance composites applicable to energy conversion and storage.