Biomass-Derived Mo2C@N, P Co-Doped Carbon as an Efficient Electrocatalyst for Hydrogen Evolution Reaction

Cost-efficient electrocatalysts derived from earth-abundant resources are urgently demanded for sustainable hydrogen production from water electrolysis. Here, biomass kapok fibers (KFs) are introduced to fabricate Mo2C@N, P co-doped carbon (Mo2C@NPC) core@shell electrocatalysts that are highly active for acidic and alkaline hydrogen evolution reaction (HER). After facile prestabilization in the presence of (NH4)2HPO4 and subsequent carbonization under an inert flow, naturally available kapok fibers convert to hollow carbon microtubes with N, P co-doping, which afterward serve as the self-template and support to obtain ultrafine Mo2C nanoparticles encapsulated by N, P co-doped carbon shells. Such shells not only boost the HER performance due to the optimized electronic configuration and the promoted conductivity but also protect Mo2C from corrosive electrolytes and result in satisfactory long-term durability. In 1.0 M HClO4 and 1.0 M KOH, Mo2C@NPC exhibits excellent performance among recently reported electrocatalysts free from noble metals, featured by low overpotentials of 127 and 155 mV at the current density of −10 mA cm–2 and the Tafel slope of 63 and 64 mV dec–1, respectively. The long-term durability of Mo2C@NPC can be confirmed by both accelerated degeneration and chronoamperometric tests. Elucidating efficient electrocatalysis on biomass-derived nanomaterials, this work will inspire further exploration of efficient electrocatalysts.