3D hierarchical MOF-derived CoP@N-doped carbon composite foam for efficient hydrogen evolution reaction

Abstract Developing efficient Pt-free electrochemical catalysts for hydrogen evolution reaction (HER) is crucial for an energy source with low pollutant emissions. Herein, zeolitic imidazolate framework-67 (ZIF-67) polyhedrons are first in situ grown on the fibrils of commercial melamine foam at room temperature, and then phosphided and carbonized to obtain the free-standing 3D hierarchical CoP@N-doped carbon composite foam (CoP@NC/CF) with interconnected architecture. The 3D interconnected carbon networks provide efficient and fast channels for the rapid transfer of ions and electrons, and inhibit the agglomeration of CoP nanoparticles. The unique structure of CoP@NC/CF thus allows for delivering the remarkable HER performance with a low overpotential of 151.3 mV at 10 mA cm-2, small Tafel slope of 64.8 mV dec-1, and excellent long-term stability. This research provides a new strategy for the rational design and facile synthesis of the free-standing 3D CoP-based catalysts for high-performance HER.