Simple synthesis of Ni-doped MoS2 nanoparticles and their application as efficient photocatalyst: experiment and COMSOL simulation

Transition metal dichalcogenides (TMDs) are favorable and interesting class of materials for photocatalytic activities. Among TMDs, MoS 2 is one of the most potential photocatalyst. Nickel (Ni)-doped MoS 2 nanoparticles (urea-based surfactant) have been synthesized utilizing a simple and cost-effective hydrothermal method. Scanning electron microscope (SEM) and X-ray diffraction (XRD) have been performed to analyze the morphological and structural properties. The results of XRD describe complete doping of Ni into MoS 2 . The images of SEM indicate the formation of rodlike nanostructures in pure MoS 2 , whereas lamellar flower-like structures are found in Ni-doped MoS 2 . Bandgap energy of pure and doped MoS 2 was measured by ultraviolet–visible spectroscopy which depicts declining trend in range of 1.96–1.72 eV from pure to 3% Ni-doped MoS 2 . The photocatalysis of prepared nanoparticles was performed by measuring decomposition of methylene blue (MB) dye under visible light. Degradation efficiencies of MB dye were 65% and 95% for pure and 3% Ni-doped MoS 2 . However, the degradation of MB dye was reduced when content of Ni into MoS 2 increased from 3 to 7%. The rate constant (of degradation efficiency) of pure MoS 2 nanoparticles was also calculated by using simulation (through COMSOL 5.3a) which was 0.00539 min −1 as compared to experimental value 0.00551 mint −1 . Reusability and scavenger effect were also analyzed by performing 5 cycles of degradation of dye and 3 different scavengers by optimal MoS 2 . Graphical abstract