Pt-decorated spinel MnCoO 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 MnCoO nanosheet arrays on nickel foam (NF) by introducing Pt species (denoted as Pt-MnCoO/NF), which is standing for excellent bifunctional electrodes. The Pt-MnCoO/NF delivers ultralow potentials of -195 mV and 350 mV at 1000 mA cm 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 *NH and *NH intermediates and the rapidly oxidization of intermediates with a fast interfacial charge transfer on Pt-MnCoO/NF. Remarkably, the Pt-MnCoO/NF assembled two-electrode hydrazine assisted water electrolyzer realizes current density of 100 mA cm and 1000 mA cm 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 H generation under ampere-level current density.