Hydrothermally synthesized VS₂/MoS₂ nanocomposites with better optoelectronic and antimicrobial response

Transition metal dichalcogenides (TMDs) in their 2D form have potential applications in optoelectronics and biomedical applications. The current study focuses on the synthesis of VS₂/MoS₂ nanocomposite by one-pot hydrothermal method with varying molybdenum (Mo) concentrations and investigating its superior antimicrobial activity and optoelectronic responses. The existence of both VS₂ and VS₂/MoS₂ hexagonal phases was revealed from X-ray diffraction study, which is well supported by the high-resolution transmission electron microscopy (HRTEM) study that confirms the formation of a VS₂/MoS₂ composite showing the presence of both VS₂ and MoS₂ planes. The crystallite size decreased with an increase in Mo content. The nanosheet-like structure of VS₂ and a flower-like structure of VS₂/MoS₂ were confirmed by field emission scanning electron microscopy (FESEM) imaging. The existence of V-S and Mo-S vibrational modes was evident from Raman analysis. The optical band gap value of the material increased with the increased amount of molybdenum concentration. This made them tunable for various optoelectronic applications. The oxidation states of different elements were probed through X-ray photoelectron spectroscopy (XPS). The antimicrobial study done using the disk diffusion method on gram-positive and negative bacteria revealed better antimicrobial efficacy on gram-negative bacteria than on gram-positive bacteria. The observed changes in its optical, morphological, and structural properties are suitable for optoelectronic applications, whereas the superior antimicrobial response is suitable for biomedical applications.