Synthesis of MoS2 nanoparticles by ultrasonication induced liquid phase exfoliation

Here in our poster we demonstrate an efficient method of synthesizing MoS₂ nanoflakes using a liquid phase exfoliation technique induced by ultrasonication. The effect of adding the alkali metal [Na+] ions to the process is also shown in detail. The differences between the two samples created with and without the addition of alkali metal ions are clearly visible in the recorded images of the samples using Transmission Electron Microscopy (TEM) technique and in their optical characterization, utilizing the absorption and photoluminescence (PL) spectra of the respective samples. The TEM images chiefly concentrate on the structural differences between the samples, clearly revealing a better yield of the nanoflakes on using the alkali metal ions in the synthesis. The recorded PL spectra of the samples display a very unique property of excitation wavelength dependent fluorescence exhibited by the nanoflakes synthesized in an alkaline environment. This property is in close resemblance to the behaviour of MoS₂ Quantum Dots. So on one hand, the addition of Na+ ions boosts the exfoliation efficiency and on the other hand it improves luminous quality of the sample. Hence the MoS₂ nanoflakes synthesized using this method can be employed in a variety of optoelectronic and light-emitting devices. The excitation dependent fluorescence feature can be employed to create futuristic multicolour display devices, sensors, and lasers.