Frenkel-defected monolayer MoS<sub>2</sub> catalysts for efficient hydrogen evolution.

Xu, Jie; Shao, Gonglei; Tang, Xuan; Lv, Fang; Xiang, Haiyan; Jing, Changfei; Liu, Song; Dai, Sheng et al. · Nat Commun · 2022

basic_science · Level V

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Abstract

Defect engineering is an effective strategy to improve the activity of two-dimensional molybdenum disulfide base planes toward electrocatalytic hydrogen evolution reaction. Here, we report a Frenkel-defected monolayer MoS<sub>2</sub> catalyst, in which a fraction of Mo atoms in MoS<sub>2</sub> spontaneously leave their places in the lattice, creating vacancies and becoming interstitials by lodging in nearby locations. Unique charge distributions are introduced in the MoS<sub>2</sub> surface planes, and those interstitial Mo atoms are more conducive to H adsorption, thus greatly promoting the HER activity of monolayer MoS<sub>2</sub> base planes. At the current density of 10 mA cm<sup>-2</sup>, the optimal Frenkel-defected monolayer MoS<sub>2</sub> exhibits a lower overpotential (164 mV) than either pristine monolayer MoS<sub>2</sub> surface plane (358 mV) or Pt-single-atom doped MoS<sub>2</sub> (211 mV). This work provides insights into the structure-property relationship of point-defected MoS<sub>2</sub> and highlights the advantages of Frenkel defects in tuning the catalytic performance of MoS<sub>2</sub> materials.