Photocatalytic activity of MoS2 nanoparticles: an experimental and DFT analysis

Transition metal dichalcogenide MoS2 nanoparticles have been synthesized by an inexpensive slow evaporation method. The X-ray diffractogram (XRD) showed that the grown particles are in crystalline nature with mixed phase. The calculated average particle size of the prepared nanoparticles is 56 nm. The Fourier transform infra-red (FTIR) and Raman studies confirm the particles are bulk MoS2 in nature. Scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX) images confirm the porosity and the presence of Mo and S elements. Photocatalytic activity of the prepared nanoparticles is tested against methylene blue (MB), and malachite green (MG) dyes and the efficiencies are found to be 93.68% and 85.33%, respectively. The degradation rate constant of MoS2 nanoparticles against MB and MG dyes are 0.0199, 0.01389 min(-1), respectively, under visible light for 75 min irradiation. A density functional theory calculation has been performed to validate the photocatalytic experimental results based on bandgap, band edge potentials, and effective mass. The DFT results are related to the experimental values, and the discussions are presented.