Electrodeposited dual-phase nickel selenide heterostructure for hydrazine-assisted water splitting

Abstract

Hydrazine-assisted water splitting offers a promising energy conversion technique for highly efficient hydrogen production. Developing bifunctional electrocatalysts that can simultaneously enhance the kinetics of both the hydrogen evolution reaction (HER) and the hydrazine oxidation reaction (HzOR) remains a significant challenge. Herein, a dual-phase nickel selenide electrode material NiSe₂/Ni_0.85Se@NF (NSNS@NF) is successfully synthesized at room temperature using a simple and straightforward electrodeposition method without using any binding reagent. Getting benefitted from the increased electrochemically active surface area, enhanced charge transfer capability at the heterostructure/electrolyte interface, and improved interfacial charge transfer between different components of the heterostructure, the NSNS@NF electrode showcased outstanding HER and HzOR performance, achieving a current density of 10 mA cm^-2 with a working potential of only -85 mV and +94 mV (vs. RHE) for HER and HzOR, respectively. Furthermore, a two-electrode electrolyzer featuring NSNS@NF as both anode and cathode requires a cell voltage of only 0.11 V to produce a current density of 10 mA cm^-2 for hydrazine-assisted overall hydrazine splitting, representing a significant drop of 1.37 V compared to overall water splitting. The electrolyzer maintains a constant current for 48 h as tested, demonstrating its remarkable longterm stability in overall hydrazine-assisted water splitting.