Experimental and theoretical investigation of synthesis and properties of dodecanethiol-functionalized MoS 2 .

Herein, we investigate the DDT (1-dodecanethiol) functionalization of exfoliated MoS 2 by using experimental and theoretical tools. For the functionalization of MoS 2 , DDT treatment was incorporated into the conventional NMP ( N -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 2 particles, indicate the formation of graphitic species on MoS 2 sheets. In addition, as the DDT ratio increases, the vacant sites on MoS 2 sheets diminish. Moreover, at an optimized ratio of DDT-NMP, the maximum number of graphitic quantum dots (GQDs) is observed on MoS 2 nanosheets. Specifically, the STEM and AFM data confirm that GQDs reside on the MoS 2 nano-sheets and also that the particle size of the DDT-MoS 2 is mostly fixed, while the NMP-MoS 2 show many smaller and distributed sizes. The comparison of PL intensities of the NMP-MoS 2 and DDT-MoS 2 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 2 and open up more opportunities for MoS 2 and GQD particles with broader applications.