Experimental and theoretical investigation of synthesis and properties of dodecanethiol-functionalized MoS.

Herein, we investigate the DDT (1-dodecanethiol) functionalization of exfoliated MoS by using experimental and theoretical tools. For the functionalization of MoS, DDT treatment was incorporated into the conventional NMP (-methyl pyrrolidone) exfoliation procedure. Afterward, it has been demonstrated that the functionalization process is successful through optical, morphological and theoretical analysis. The D, G and 2LA peaks seen in the Raman spectrum of exfoliated NMP-MoS particles, indicate the formation of graphitic species on MoS sheets. In addition, as the DDT ratio increases, the vacant sites on MoS sheets diminish. Moreover, at an optimized ratio of DDT-NMP, the maximum number of graphitic quantum dots (GQDs) is observed on MoS nanosheets. Specifically, the STEM and AFM data confirm that GQDs reside on the MoS nano-sheets and also that the particle size of the DDT-MoS is mostly fixed, while the NMP-MoS show many smaller and distributed sizes. The comparison of PL intensities of the NMP-MoS and DDT-MoS samples states a 10-fold increment is visible, and a 60-fold increment in NIR region photoluminescent properties. Moreover, our results lay out understanding and perceptions on the surface and edge chemistry of exfoliated MoS and open up more opportunities for MoS and GQD particles with broader applications.