Polyoxometalate and Resin-Derived P-Doped Mo₂ C@N-Doped Carbon as a Highly Efficient Hydrogen-Evolution Reaction...

A new type of P-doped Mo₂ C coated by N-doped carbon (P-Mo₂ C@NC) has been successfully prepared by calcining a mixture of H₃ [PMo₁₂ O₄₀ ] polyoxometalates (POMs) and urea-formaldehyde resin under an N₂ atmosphere. Urea-formaldehyde resin not only serves as the carbon source to ensure carbonization but also facilitates the uniform distribution of POM precursors, which efficiently avoid the aggregation of Mo₂ C particles at high temperatures. TEM analysis revealed that the average diameter of the Mo₂ C particles was about 10 nm, which is coated by a few-layer N-doped carbon sheet. The as-prepared P-Mo₂ C@NC displayed excellent hydrogen-evolution reaction (HER) performance and long-term stability in all pH environments. To reach a current density of 10 mA cm^-2 , only 109, 159, and 83 mV were needed for P-Mo₂ C@NC in 0.5 m H₂ SO₄ (pH 0), 0.1 m phosphate buffer (pH 7), and 1 m KOH (pH 14), respectively. This could provide a high-yield and low-cost method to prepare uniform nanosized molybdenum carbides with highly efficient and stable HER performance.