SERS-based detection of efficient removal of organic dyes using molybdenum dichalcogenide nanostructures

Two-dimensional materials have been popular in recent times owing to their special properties that can lead to several applications. In particular, transition metal dichalcogenides have been reported to be potential candidates for photocatalytic degradation and adsorptive removal of organic pollutants. Molybdenum-based chalcogenides have shown to be very efficient in removing pollutant dyes from aqueous solutions. Here, we report a facile method for the removal of organic dyes from aqueous solution using molybdenum dichalcogenide (MoX2; X = S, Se, Te) based nanostructures. The molybdenum dichalcogenide nanostructures were synthesized chemically using the simple hydrothermal method. The samples were characterized by X-ray diffraction, Raman Spectroscopy, UV-visible spectroscopy, and scanning electron microscopy. The as-prepared samples have been utilized as an adsorbent for the removal of common organic dyes such as methylene blue (MB), methyl orange (MO), malachite green (MG), rhodamine B (RhB), rhodamine 6 G (R6G) and mixtures of these organic dyes from aqueous solution. It was observed that among the synthesized samples, molybdenum disulfide (MoS2) presented excellent adsorption affinity towards these dyes. In addition, selective adsorption of MB in the presence of MO and RhB was demonstrated. Furthermore, the application of surface-enhanced Raman scattering (SERS) to monitor the degradation of the dyes in the experiments was also investigated.