Rough-surfaced molybdenum carbide nanobeads grown on graphene-coated carbon nanofibers membrane as free-standing hydrogen evolution reaction electrocatalyst

A novel free-standing pie-like paper electrode composed of Mo₂C nanobeads on graphene-coated carbon nanofibers (G-CNF) membrane was rationally designed as advanced electrocatalyst for hydrogen evolution reaction (HER). A thin layer of graphene is coated on the surface of CNF membrane, forming a “crust” on fibrous web architecture. The unique design of the all-carbon membrane, which is a 3D interconnected conductive framework of nanofibers, reduces the resistance of electron and ion transport during the electrocatalyzing process. With G-CNF performing as support, well-shaped Mo₂C nanobeads were immobilized on the fibers through hydrothermal and calcination procedures, offering rich catalytic sites on the exposed rough surface. Owing to all these merits, the composite membrane of Mo₂C-G-CNF exhibits high HER catalytic activity with onset potential of 115 mV in acidic solution and 108 mV in basic solution. Furthermore, the good durability in both acidic and basic environment guarantees its practical application as free-standing electrode material.