Polyoxometalate and Resin-Derived P-Doped Mo2C@N-Doped Carbon as a Highly Efficient Hydrogen-Evolution Reaction Catalyst at All pH Values

A new type of P-doped Mo2C coated by N-doped carbon (P-Mo2C@NC) has been successfully prepared by calcining a mixture of H-3[PMo12O40] polyoxometalates (POMs) and urea-formaldehyde resin under an N-2 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 Mo2C particles at high temperatures. TEM analysis revealed that the average diameter of the Mo2C particles was about 10nm, which is coated by a few-layer N-doped carbon sheet. The as-prepared P-Mo2C@NC displayed excellent hydrogen-evolution reaction (HER) performance and long-term stability in all pH environments. To reach a current density of 10mAcm(-2), only 109, 159, and 83mV were needed for P-Mo2C@NC in 0.5m H2SO4 (pH0), 0.1m phosphate buffer (pH7), and 1m KOH (pH14), respectively. This could provide a high-yield and low-cost method to prepare uniform nanosized molybdenum carbides with highly efficient and stable HER performance.