Ultrathin nanosheet metal–organic framework@NiO/Ni nanorod composites

Two-dimensional metal–organic frameworks are a family of materials with great potential for electrocatalysis; however, these materials usually have the poor thermodynamic stability and require harsh preparation conditions. Here, we describe a facile approach for preparing ultrathin nanosheet metal–organic [email protected]/Ni nanorods with increased stability and highly active sites compared with in case of pristine metal–organic frameworks. These peculiar hierarchical nanocomposites exhibit excellent properties for urea electrolysis, including abundant exposed active sites owing to their nanosheet-nanorod hierarchical structure, enriched Ni-species, and improved stability. The prepared composites demonstrate superior electrocatalytic performance toward the urea oxidation reaction with a low overpotential of only 170 mV to reach 10 mA cm−2, a small Tafel slope of 48.1 mV dec-1, and a low cell voltage of 1.42 V for overall urea electrolysis, with outstanding long-term durability (15,000 s with only 7.1% activity decay). This combination between metal–organic frameworks and materials with high thermodynamic stability offers a strategy for further development of excellent electrocatalysts.