Single Atomic Vacancy Catalysis.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31398001.
- Also identified by DOI 10.1021/acsnano.9b05226.
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Abstract
Single atom catalysts provide exceptional activity. However, measuring the intrinsic catalytic activity of a single atom in real electrochemical environments is challenging. Here, we report the activity of a single vacancy for electrocatalytically evolving hydrogen in two-dimensional (2D) MoS<sub>2</sub>. Surprisingly, we find that the catalytic activity per vacancy is not constant but increases with its concentration, reaching a sudden peak in activity at 5.7 × 10<sup>14</sup> cm<sup>-2</sup> where the intrinsic turn over frequency and Tafel slope of a single atomic vacancy was found to be ∼5 s<sup>-1</sup> and 44 mV/dec, respectively. At this vacancy concentration, we also find a local strain of ∼3% and a semiconductor to metal transition in 2D MoS<sub>2</sub>. Our results suggest that, along with increasing the number of active sites, engineering the local strain and electrical conductivity of catalysts is essential in increasing their activity.