Se-Rich MoSe<sub>2</sub> Nanosheets and Their Superior Electrocatalytic Performance for Hydrogen Evolution Reaction.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32356967.
- Also identified by DOI 10.1021/acsnano.0c02593.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Two-dimensional MoSe<sub>2</sub> has emerged as a promising electrocatalyst for the hydrogen evolution reaction (HER), although its catalytic activity needs to be further improved. Herein, we report Se-rich MoSe<sub>2</sub> nanosheets synthesized using a hydrothermal reaction, displaying much enhanced HER performance at the Se/Mo ratio of 2.3. The transition from the 2H to the 1T' phase occurred as Se/Mo exceeded 2. Structural analysis revealed the presence of Se adatoms as well as the formation of Se-Se bonding. Based on first-principles calculations, we propose two equally stable Se-rich structures. In the first one, excess Se atoms bridge two MoSe<sub>2</sub> layers <i>via</i> the interlayer Se-Se bonds. In the second one, the Se atoms substitute for the Mo atoms, and extra Se atoms are added closest to the Mo-substituted Se. Calculation of Gibbs free energy along the reaction path indicates that the Se adatoms of the second model are the most active sites for HER.