Synthesis of hollow CoSe2/MoSe2 nanospheres for efficient hydrazine-assisted hydrogen evolution

Hydrazine-assisted hydrogen evolution cell has been regarded as a promising route to replace conventional water splitting because of the lower thermodynamic oxidation potential. Therefore, the design and synthesis of highly efficient bifunctional electrocatalysts for anodic hydrazine oxidation reaction (HzOR) and cathodic hydrogen evolution reaction (HER) are crucial and highly desired. In this work, we report a facile synthesis strategy to prepare hollow CoSe2/MoSe2 nanospheres with abundant active interfaces for hydrazine-assisted hydrogen production. The homogeneous mixing of Co and Mo ions in the metal organic framework precursors ensures the formation of intimately contacted interfaces after selenization, leading to the “reinforced concrete” CoSe2/MoSe2 composites. Benefiting from the CoSe2/MoSe2 interfaces, the hollow CoSe2/MoSe2 nanosphere performs a low HER overpotential of 168 mV with an excellent stability over 12 h. Additionally, it also exhibits a low overpotential of 386 mV (vs. RHE) for HzOR and an ultralow cell voltage (1 mA cm−2) of 160 mV, which are among the best reported performance of powdered electrocatalysts. The present work develops a promising bifunctional electrocatalyst with active interfaces for energy-saving electrolytic hydrogen production.