A hierarchical carbon foam-hosted Co 2 P nanoparticles monolithic electrode for ampere-level and super-durable electrocatalytic hydrogen production.

In this work, we develop a hierarchical carbon foam-based monolithic electrode (Co 2 P@HCF) from Co 2+ -adsorbed polyvinyl alcohol (PVA) sponge via the successive carbonization and phosphorization. Owing to the 3D hierarchical porous structure, excellent electrolyte wettability, good mechanical strength, and intimate embedding of highly dispersed Co 2 P nanoparticles, the Co 2 P@HCF electrode delivers a high current density of 1.0 A cm -2 for the hydrogen evolution reaction (HER) at ultralow overpotentials of 189.6 and 218.6 mV in 0.5 M H 2 SO 4 and 1.0 M KOH solutions, respectively, with remarkable durability for 100 h.