Effect of single-layer MoS$_{\mathrm{2}}$ support on the geometry and electronic structure of transition metal nanoparticles

We present results of density functional theory based calculations of the geometry and electronic structure of small (29-atom) transition (TM) nanoparticles (NPs) supported on single-layer MoS$_{\mathrm{2}}$, with and without S-vacancy defects. Among the prototypes considered, the NPs bind more strongly on defect-laden rather than pristine MoS$_{\mathrm{2}}$ -- in the order Cu$_{\mathrm{29}}$\textgreater Ag$_{\mathrm{29}}$\textgreater Au$_{\mathrm{29}}$ for defect-laden and of Cu$_{\mathrm{29}}$\textgreater Au$_{\mathrm{29}}$\textgreater Ag$_{\mathrm{29}}$ for pristine. Interestingly, van der Waals interactions play a stronger role in the case of Au$_{\mathrm{29}}$ than in the other two. Strong interaction between the NPs and defect-laden MoS$_{\mathrm{2}}$ is also facilitated by the close contact of their ``boat-shape'' with v-like-shape of single-layer MoS$_{\mathrm{2}}$ formed when laden with S vacancies. We also find that the trend for the charge transfer from NPs to MoS$_{\mathrm{2}}$, regardless of its form (pristine or defect-laden)$_{\mathrm{,}}$ is$_{\mathrm{\thinspace }}$Cu$_{\mathrm{29}}$\textgreater Ag$_{\mathrm{29}}$\textgreater Au$_{\mathrm{29}}$ and that defect-laden MoS$_{\mathrm{2}}$ donates more charge than its pristine counterpart does. Among all NPs, the largest shift of d-band center toward the Fermi level occurs in the case of defect-laden-supported Au$_{\mathrm{29}}$. Our results suggest that defect-laden MoS$_{\mathrm{2}}$ is good support for anchoring and for tuning electronic properties of TM NPs, which have potential in catalytic applications.