Ultra-small porous WN/W2C nanoparticles for sustained hydrogen production by a polyoxometalate-intercalated pyrolysis strategy

Abstract

Designing low-cost, stable and earth-abundant transition metal-based electrocatalysts to replace Pt-based catalysts is of significant importance for green and sustainable energy technologies. W-based carbon materials are crucial hydrogen evolution reaction (HER) electrocatalysts, but the synthesis and stability of such materials still face great challenges that hamper the development of such applications. Herein, WN/W₂C porous composites with a carbon shell (WN/W₂C@PC) were prepared by forming a pyrolytic polyoxometalate-intercalated layered double hydroxide (LDH) with glucose and NH₄Cl as templates. The composites possess a high specific surface area of 633.74 m² g⁻¹, which offers more active sites and promotes the HER performance. Compared with most non-precious metal-based electrocatalysts, WN/W₂C@PC undergoes an outstanding HER with a low overpotential of 121.3 mV and 91 mV at 10 mA cm⁻² under 0.5 M H₂SO₄ and 1 M KOH, respectively, and exhibits robust long-term stability. This work provides novel insights for the rational design and preparation of efficient non-precious metal-based HER electrocatalysts.