One-pot synthesis of Ni3S2/Co3S4/FeOOH flower-like microspheres on Ni foam: An efficient binder-free bifunctional electrode towards overall water splitting

Abstract

Overall water splitting using highly effective and low-cost bifunctional electrocatalysts is a promising method for hydrogen production. Herein, Ni3S2/Co3S4/FeOOH flower-like microspheres composed of Ni3S2/Co3S4 nanosheets and FeOOH nanoparticles are in-situ generated on Ni foam (NF) by a facile one-step hydrothermal approach. The NF-supported Ni3S2/Co3S4/FeOOH can serve as an efficient binder-free bifunctional electrode for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline medium. The overpotentials at current density of 10 mA cm−2 are 158 and 181 mV for HER and OER, respectively. Moreover, the electrode exhibits remarkable performance for overall water splitting, requiring only a low voltage of 1.58 V to achieve the current density of 10 mA cm−2, and displaying a good long-term stability. The synergistic effect of different functional components and the unique hierarchical structure are responsible for the superior electrocatalytic performances of Ni3S2/Co3S4/FeOOH compared to Ni3S2, Ni3S2/Co3S4 and Ni3S2/FeOOH.