Tungsten nitride on a porous carbon support as a highly durable electrocatalyst for the hydrogen evolution reaction

Abstract

The hydrogen evolution reaction is a key reaction in the field of sustainable energy, and platinum is recognised as a state-of-the-art catalyst for this reaction. The cost and scarcity of platinum drive us to look for low-cost and effective alternatives. Among the various metal nitrides, tungsten nitride has been less explored as an HER electrocatalyst despite its stability under extreme pH conditions. WN–carbon composites were synthesised using urea as a nitrogen precursor, and the synthesised WN/NC catalyst exhibits a lower HER overpotential of 200 mV in an acidic medium and 230 mV in an alkaline medium. The mass activity was estimated as 24.2 A g⁻¹ in 0.5 M H₂SO₄, which is much higher than the mass activity in 1 M KOH electrolyte (13.5 A g⁻¹). A homemade water electrolysis system demonstrates that the WN–carbon composite-coated carbon electrode exhibits hydrogen evolution up to 770 mL min⁻¹ g_cat⁻¹ at a constant current density of 100 mA cm⁻². The results demonstrate that the WN with an appropriate carbon support may be a promising alternative to platinum-based electrocatalysts for the hydrogen evolution reaction.