Hierarchical multi-component nanosheet array electrode with abundant NiCo/MoNi4 heterostructure interfaces enables superior bifunctionality towards hydrazine oxidation assisted energy-saving hydrogen generation

Abstract

Using hydrazine oxidation reaction (HzOR) to replace sluggish oxygen evolution could be an effective strategy to realize energy-saving hydrogen production, while the development of efficient bifunctional electrocatalysts still remains a significant challenge. Herein, we report a hierarchical multi-component nanosheet arrays grown on Ni foam composed of abundant NiCo/MoNi4 heterostructure interfaces on the amorphous MoOx substrate (denoted as NiCo-MoNi4 HMNAs/NF), which can simultaneously achieve the current density of 10 mA cm−2 at a low working potential of −30 mV (vs. RHE) for HzOR and a small overpotential of 68 mV for HER. Importantly, the post-catalysis characterizations further disclose that the partial formation of transition metal hydroxide species probably endow favorable absorption for hydroxyl intermediates, leading to the high performance and durability. Moreover, a two-electrode system based on NiCo-MoNi4 HMNAs/NF can reach the current density of 250 mA cm−2 with a cell voltage of 0.63 V for overall hydrazine splitting (OHzS) system.