Frenkel-defected monolayer MoS2 catalysts for efficient hydrogen evolution

While material defect sites are active for chemical reactions, it is important to understand how different defect types impact reactivity. Here, authors prepare Frenkel-defected MoS2 monolayers and demonstrate improved performances for H-2 evolution electrocatalysis than pristine or doped MoS2. 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 MoS2 catalyst, in which a fraction of Mo atoms in MoS2 spontaneously leave their places in the lattice, creating vacancies and becoming interstitials by lodging in nearby locations. Unique charge distributions are introduced in the MoS2 surface planes, and those interstitial Mo atoms are more conducive to H adsorption, thus greatly promoting the HER activity of monolayer MoS2 base planes. At the current density of 10 mA cm(-2), the optimal Frenkel-defected monolayer MoS2 exhibits a lower overpotential (164 mV) than either pristine monolayer MoS2 surface plane (358 mV) or Pt-single-atom doped MoS2 (211 mV). This work provides insights into the structure-property relationship of point-defected MoS2 and highlights the advantages of Frenkel defects in tuning the catalytic performance of MoS2 materials.

Automated summary

This study demonstrates the improved performance of Frenkel-defected MoS2 monolayers in electrocatalytic hydrogen evolution reaction compared to pristine or doped MoS2. The findings highlight the advantages of defect engineering in tuning the catalytic performance of MoS2 materials.