The Weyl Semimetals MIrTe4 (M = Nb, Ta) as Efficient Catalysts for Dye-sensitized Hydrogen Evolution

The prevalent global energy crisis calls for searching viable pathways for generating green hydrogen as an alternative energy resource. Dye-sensitized photocatalytic water splitting is a feasible solution to produce green hydrogen. However, identifying suitable catalysts has been one of the bottlenecks in driving dye-sensitized photocatalysis efficiently. In this work, we report a new class of electrocatalysts based on the layered Weyl semimetals MIrTe4 (M = Nb, Ta) for the Eosin Y (EY)-sensitized hydrogen evolution reaction (HER) under visible light illumination. NbIrTe4 and TaIrTe4 exhibit HER activities of ~ 18000 and ~ 14000 mol.g-1, respectively after 10h of irradiation with visible light. Time-dependent UV-Vis spectroscopy and high-pressure liquid chromatography coupled with mass spectroscopy analysis shed light on the reaction dynamics and enable deeper understanding of the observed trend in hydrogen evolution rates for MIrTe4 materials. MIrTe4 (M = Nb, Ta) semimetals outperform related catalysts including transition metal dichalcogenides and other Weyl semimetals in terms of HER activity using EY as photosensitizer and triethanolamine as the sacrificial agent. We hypothesize that the topology-related band inversion in MIrTe4 Weyl semimetals promotes a high density of metal d-states near the Fermi level, driving their high catalytic performance. This study introduces a new class of layered Weyl semimetals as efficient catalysts, and provides perspectives for designing topology-enhanced catalysts.