Reduced graphene oxide composite Ni3S2 microspheres grown directly on nickel foam as an efficient electrocatalyst for OER

The development of cheap, high-efficiency, and stable oxygen evolution reaction (OER) electrocatalysts is a current research hotspot. In this work, reduced graphene oxide (rGO) composite Ni3S2 microspheres grown directly on nickel foam (Ni3S2-rGO/NF) were prepared by tube furnace calcination and hydrothermal method. The Ni3S2-rGO/NF had excellent OER catalytic activity and stability with an overpotential of 303 mV at the current density of 100 mA cm−2, which was 100 mV lower than that of Ni3S2/NF, and its Tafel slope was as low as 23 mV·dec−1. The main reason for enhancing OER activity of the Ni3S2-rGO/NF is due to synergistic effect of Ni3S2 microspheres and rGO, which inhibited the production of NiS and refined the micron size of Ni3S2. This work offers a new method for developing stable and efficient OER catalysts.