Theoretical realization of hybrid Weyl state and associated high catalytic performance for hydrogen evolution in NiSi

TL;DR

This paper demonstrates that topological properties of NiSi, a hybrid Weyl semimetal, significantly enhance its catalytic activity for hydrogen evolution, offering a new route for designing non-precious metal catalysts.

Contribution

It introduces topological engineering as a novel approach to develop high-performance HER catalysts, identifying NiSi as a promising non-precious metal catalyst through computational screening.

Findings

NiSi exhibits bulk Weyl nodes and surface Fermi arcs near the Fermi level.

Surface of NiSi has a Gibbs free energy close to zero, outperforming Pt.

Topological charge carriers participate in the HER process.

Abstract

For electrochemical hydrogen evolution reaction (HER), developing high-performance catalysts without containing precious metals has been a major research focus in the current. Herein, we show the feasibility of HER catalytic enhancement in Ni-based materials based on topological engineering from hybrid Weyl states. Via a high-throughput computational screening from 140 000 materials, we identify a chiral compound NiSi is a hybrid Weyl semimetal (WSM) with showing bulk type-I and type-II Weyl nodes and long surface Fermi arcs near the Fermi level. Sufficient evidences verify that topological charge carriers participate in the HER process, and make the certain surface of NiSi highly active with the Gibbs free energy nearly zero (0.07 eV), which is even lower than Pt and locates on the top of the volcano plots. This work opens up a new routine to develop no-precious-metal-containing HER catalysts via topological engineering, rather than traditional defect engineering, doping engineering, or strain engineering.