Trimetallic Metal–Organic Framework Derived Carbon‐Based Nanoflower Electrocatalysts for Efficient Overall Water Splitting

Abstract Searching desirable cost‐effective electrocatalysts for overall water splitting is of great importance for the hydrogen production industry. Here a facile synthesis of trimetallic carbon nanoflower electrocatalysts is reported which are derived from Co 2+ /Fe 2+ /Ni 2+ ratio adjustable metal–organic frameworks (MOFs). The unique nanosheet‐assembled multiscale nanoflower morphology can enlarge the catalyst/electrolyte contact area, and the synergistic electronic effects between trimetallic components endow the trimetallic carbon nanoflower electrocatalysts with more oxygen vacancies and a higher degree of graphitization of carbon, thus showing excellent activity. The optimized Co0.2Fe0.8Ni‐OCNF reaches a current density of 10 mA cm −2 at low overpotential of 291 mV with a very small Tafel slope of 36.1 mV dec −1 and 1.65 V@10 mA cm −2 for a two‐electrode water electrolysis in an alkaline solution, outperforming the commercial IrO 2 electrocatalysts. The results may pave the way to the development of more efficient multicomponent nanosheet‐assembled multiscale nanomaterials for various catalytic applications.