Interface engineering of tungsten carbide/phosphide heterostructures anchored on N,P-codoped carbon for high-efficiency hydrogen evolution reaction

The development of inexpensive and efficient Pt-free electrocatalysts for the hydrogen evolution reaction (HER) is greatly crucial for water electrolysis. Tungsten carbide (WC) exhibiting a Pt-like electronic structure represents an attractive alternative, although its overall performance is limited by the strong W-H bond that impedes hydrogen desorption. Here, we employed an in-situ interface engineering strategy to construct high-performance and cost effective electrocatalysts comprising WC/tungsten phosphide (WP) heterostructures that were anchored on N,P-codoped carbon (WC/WP@NPC) via a one-step pyrolysis of a melamine polyphosphate/WO3 hybrid in an inert atmosphere. Owing to the crystal structure compatibility and electron-rich property of WP, it optimizes the electronic structure and hydrogen adsorption configuration of WC, thus significantly weakening the W-H bond with a thermoneutral Gibbs free energy of hydrogen adsorption (ΔGH*) of −0.05 eV. Additionally, NPC ensures fast electron transport and structural stability of the WC/WP@NPC ternary architecture. These synergistically lead to outstanding HER performances of the catalyst in acidic and alkaline media. Our finding offers a new strategy for designing Pt-alternative electrocatalysts with outstanding electrochemical performances for high-efficiency water splitting and other applications.