Pt-decorated spinel MnCo₂O₄ nanosheets enable ampere-level hydrazine assisted water electrolysis

Coupling hydrazine oxidation reaction (HzOR) with hydrogen evolution reaction (HER) has been widely concerned for high efficiency of green hydrogen preparation with low energy consumption. However, the lacking of bifunctional electrodes with ampere-level performance severely limits its industrialization. Herein, we put forward an efficient active site anchored strategy for MnCo₂O₄ nanosheet arrays on nickel foam (NF) by introducing Pt species (denoted as Pt-MnCo₂O₄/NF), which is standing for excellent bifunctional electrodes. The Pt-MnCo₂O₄/NF delivers ultralow potentials of -195 mV and 350 mV at 1000 mA cm^-2 as well as robust stability for HzOR and HER, respectively. The study of in-situ Raman and reaction kinetics reveal that the formation of key adsorbed *NH₂ and *N₂H₄ intermediates and the rapidly oxidization of intermediates with a fast interfacial charge transfer on Pt-MnCo₂O₄/NF. Remarkably, the Pt-MnCo₂O₄/NF assembled two-electrode hydrazine assisted water electrolyzer realizes current density of 100 mA cm^-2 and 1000 mA cm^-2 at 0.16 V and 0.62 V with over 80 h stability. This work provides a promising way to design efficient electrodes for energy-saving H₂ generation under ampere-level current density.