Dynamic restructuring of nickel sulfides for electrocatalytic hydrogen evolution reaction.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38914549.
- Also identified by DOI 10.1038/s41467-024-49015-4 and PMC identifier 11196257.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Transition metal chalcogenides have been identified as low-cost and efficient electrocatalysts to promote the hydrogen evolution reaction in alkaline media. However, the identification of active sites and the underlying catalytic mechanism remain elusive. In this work, we employ operando X-ray absorption spectroscopy and near-ambient pressure X-ray photoelectron spectroscopy to elucidate that NiS undergoes an in-situ phase transition to an intimately mixed phase of Ni<sub>3</sub>S<sub>2</sub> and NiO, generating highly active synergistic dual sites at the Ni<sub>3</sub>S<sub>2</sub>/NiO interface. The interfacial Ni is the active site for water dissociation and OH* adsorption while the interfacial S acts as the active site for H* adsorption and H<sub>2</sub> evolution. Accordingly, the in-situ formation of Ni<sub>3</sub>S<sub>2</sub>/NiO interfaces enables NiS electrocatalysts to achieve an overpotential of only 95 ± 8 mV at a current density of 10 mA cm<sup>-2</sup>. Our work highlighted that the chemistry of transition metal chalcogenides is highly dynamic, and a careful control of the working conditions may lead to the in-situ formation of catalytic species that boost their catalytic performance.