Enhancing the Hydrogen Evolution Performance of Tungsten Diphosphide on Carbon Fiber through Ruthenium Modification.

Abstract

Hydrogen-based energy systems hold promise for sustainable development and carbon neutrality, minimizing environmental impact with electrolysis as the preferred fossil-fuel-free hydrogen generation method. Effective electrocatalysts are required to reduce energy consumption and improve kinetics, given the need for additional voltage (overpotential, η) despite the theoretical water splitting potential of 1.23 V. To date, platinum has been acknowledged as the most effective but expensive hydrogen evolution reaction (HER) catalyst. Hence, we introduce a cost-effective (∼2-fold cheaper) ruthenium-modified tungsten diphosphide (Ru/WP2) catalyst on carbon fiber for HER in ∼0.5 M H2SO4, with η ≈ 34 mV at -10 mA cm-2 which can be comparable (only ∼2-fold higher) to benchmark Pt/C (η ≈ 17 mV). The HER performance of WP2 can be enhanced through the modification of ruthenium, as indicated by the electrochemical characterizations. Considering the Tafel value of ∼40 ± 0.2 mV dec-1, it can be inferred that Ru/WP2 follows the Volmer-Heyrovsky reaction pathway for hydrogen generation. Furthermore, the Faradaic efficiency estimation indicates that Ru/WP2 demonstrates a minimal loss of electrons during the electrochemical reaction with an estimated value of ∼98.7 ± 1.4%. Therefore, this study could emphasize the potential of the Ru/WP2 electrode in advancing sustainable hydrogen production through water splitting.