Molybdenum Carbide Nanoclusters on N-Doped Carbon Nanocages for Electrocatalytic Hydrogen Evolution

Molybdenum carbides are attractive electrocatalysts for hydrogen evolution because of their Pt-like electronic structures and lower cost but are often troubled by low active surface area. Herein, we develop a convenient strategy to control the size of molybdenum carbides by using subnanometer (TBA)3PMo12O40 (TBA= tetrabutyl ammonium) as the Mo precursor, in situ-coated polydopamine as the C source and antisintering agent, and nitrogen-doped hierarchical carbon nanocages (hNCNC) as the support. The resulting mixed-phase MoC/Mo2C nanoclusters on hNCNC (MoxC/hNCNC) have an average size of 1.4 nm, which is smaller and more uniform than the counterparts synthesized with different Mo or C sources and an undoped hierarchical carbon nanocage support. The as-prepared MoxC/hNCNC presents good activity and stability in electrocatalytic hydrogen evolution, with an overpotential of 159 mV@10 mA cm–2 and negligible potential decay after 10000 cycles of accelerated durability testing in an acidic electrolyte.