Mo₃s₄ nanorod: An effective photocatalyst for the degradation of organic dyes in aqueous solution

Background: A molybdenum sulfide (Mo₃S₄) nanorod photocatalyst was synthesised through the facile hydrothermal method and applied in the degradation of Rhodamine B and Methyl Blue dyes under visible light irradiation. Method: The Mo₃S₄ nanorod was synthesised using sodium molybdate, sodiumdiethyldithiolcarbonate and ethylenediaminetetraacetic acid as molybdenum and sulfur sources, and capping agent respectively. The photocatalyst was characterized by using XRD, FTIR, TEM, SEM, EDS and UV-Vis spectroscopies. Results: SEM result shows that the synthesised sample has a rod-like shape made up of several thin sheets. The XRD result revealed the Mo₃S₄ nanorod to exist in the Rhombohedral phase. The energy band gap of the sample was calculated to be 2.02 eV. The synthesised Mo₃S₄ nanorod showed great potential in the removal of both RhB and MB in aqueous solution. 85.46% and 99.78% removals of RhB and MB dyes respectively were achieved in 90 min. Conclusion: It was also observed that the photodegradation of both RhB and MB follows pseudo-first order kinetics, with apparent rate constants of 0.0089 min-1 and 0.0118 min-1 for RhB and MB respectively.