Phosphorus-Modified Tungsten Nitride/Reduced Graphene Oxide as a High-Performance, Non-Noble-Metal Electrocatalyst for the Hydrogen Evolution Reaction

Phosphorus-modified tungsten nitride/reduced graphene oxide (P-WN/rGO) is designed as a high-efficient, low-cost electrocatalyst for the hydrogen evolution reaction (HER). WN (ca. 3nm in size) on rGO is first synthesized by using the H-3[PO4(W3O9)(4)] cluster as a W source. Followed by phosphorization, the particle size increase slightly to about 4nm with a P content of 2.52at%. The interaction of P with rGO and WN results in an obvious increase of work function, being close to Pt metal. The P-WN/rGO exhibits low onset overpotential of 46mV, Tafel slope of 54mVdec(-1), and a large exchange current density of 0.35mAcm(-2) in acid media. It requires overpotential of only 85mV at current density of 10mAcm(-2), while remaining good stability in accelerated durability testing. This work shows that the modification with a second anion is powerful way to design new catalysts for HER.