Heterointerface engineering of Rh/Pd metallene for hydrazine oxidation-assisted energy-saving hydrogen production

Water electrolysis for hydrogen production consumes abundant electronic energy owing to the sluggish oxygen evolution reaction (OER), so the integration of the hydrogen evolution reaction (HER) with thermodynamically more favorable oxidation reactions is a promising strategy for energy-efficient hydrogen production. Herein, we propose the epitaxial confinement of rhodium nanoparticles (NPs) to palladium metallene (Rh/Pd metallene) for hydrogen production assisted by the hydrazine oxidation reaction (HzOR). The two-dimensional structure of Rh/Pd metallene provides sufficient active sites as well as a rapid charge transfer rate. The interface of Pd metallene with Rh NPs ensembles to modulate the electronic state, thus optimizing the adsorption energy of reaction intermediates. The Rh/Pd metallene exhibits splendid HER and HzOR activities, with overpotentials of 59 and 7 mV at 10 mA cm−2, respectively. In the two-electrode construction of a hydrazine oxidation-assisted water splitting system, the Rh/Pd metallene only needs a low overpotential of 0.19 V to produce hydrogen at a current density of 100 mA cm−2. This research offers a viable approach for designing nanosheet/nanoparticle heterojunction as an attractive modular platform for energy-saving hydrogen production.