Ultra-High-Field 67Zn and 33S NMR Studies Coupled with DFT Calculations Reveal the Structure of ZnS Nanoplatelets Prepared by an Organometallic Approach

Herein, we report the successful characterization of sulfur vacancies in ZnS nanoplatelets by in-depth high-field and DNP-enhanced solid-state NMR of 33S and 67Zn nuclei and DFT modeling. This two-dimensional 1 nm-thick nanomaterial was obtained by reacting a dicyclohexyl zinc complex, ZnCy2, with (TMS)2S as the S source under mild conditions (45 °C) in dodecylamine. The joint experimental and theoretical studies on these nanoplatelets evidenced that a large fraction of the Zn and S atoms are located near the surface covered by dodecylamine and that the deviation from stoichiometry (agreeing with energy gap and photoluminescence properties of non-stoichiometric material) is due to sulfur vacancies. Additionally, this work reports the first 33S DNP-NMR spectrum reported in the literature alongside several ultra-high-field 33S and 67Zn solid-state NMR spectra.