Hierarchical Nanostructures of MoS2 for Visible Light Photocatalytic Degradation of Methylene Blue Dye

The visible light photocatalytic performance of nanostructured molybdenum disulphide (MoS2) is reported. Morphology studies reveal a hierarchical nanostructure with a nanoflower shape comprised of nanosheets. The nanoflower and nanosheet dimensions are dependent on the hydrothermal growth temperature. There are no major differences in crystallographic texture or composition with growth temperature (170, 190 and 210 degrees C). The as-synthesized photocatalysts showed superior adsorption under visible regime and hindered photoinduced charge carrier recombination. Photocatalytic degradation of methylene blue dye under visible light irradiation using MoS2 nanosheets grown at 210 degrees C showed 96 % degradation in 70 min. Electrochemical studies indicate decrease in charge transfer resistance from 170 to 112 Omega with increase in growth temperature from 170 to 210 degrees C due to faster charge carrier separation and transportation. This change can be correlated with the change in dimensions of the nanostructures and demonstrates nanostructure-mediated photocatalytic activity in MoS2.