Stabilized cobalt-based nanofilm catalyst prepared using an ionic liquid/water interfacial process for hydrogen generation from sodium borohydride.

The design and construction of transition metal catalysts with high performance and low-cost characteristics are imperative for liquid hydrogen storage materials. In this study, we prepared ultrathin carbon-stabilized Co-doped CoxOy nanofilms (C-Co/CoxOy NFs) using an ionic liquid/water interface strategy for sodium borohydride (NaBH4) hydrolysis. Owing to its two-dimensional (2D) NF structure and the protective effects of the composite carbon, the C-Co/CoxOy NF catalyst exhibited remarkable activity and durability for hydrogen generation from NaBH4 hydrolysis. The hydrogen generation rate reached 8055 mL·min-1·gCo-1 (5106 mL·min-1·gCat-1) and the catalyst could be recycled more than 20 times, surpassing most reported metal-based catalysts under comparable conditions. In addition, the exceptional 2D Co-based NF structures, with numerous active sites, assisted in the activation of NaBH4 and water molecules, promoting hydrogen production. Thus, these results provided an in-depth understanding of hydrogen generation from NaBH4 hydrolysis, and an effective strategy for rationally designing highly active and durable 2D NF catalysts.