Photocatalytic activity of a hydrothermally synthesized γ-Fe2O3@Au/MoS2 heterostructure for organic dye degradation under green light.

[Display omitted] • The bandgap was estimated and reported to be 0.91 eV (indirect) and 2.23 eV (direct). • The optically and electrically activity has been seen in the Raman spectra. • Methyl blue was used for catalysts' properties and 98 %< efficiency was measured. • Photocatalysts mechanism was described. • HOMO-LUMO energy gap for each step was described with simulation work. This article reports on a hydrothermally synthesized γ-Fe 2 O 3 @Au/MoS 2 heterostructure with excellent photocatalytic properties for the degradation of Methyl blue dye under green light at room temperature (300 K). The bandgap of the heterostructure was estimated from the Tauc plot and found as 0.91 eV (indirect) and 2.23 eV (direct). The optical and electrical activity of the heterostructure was revealed by the Raman spectra. The photocatalytic properties of γ-Fe 2 O 3 @Au/MoS 2 heterostructures were investigated by degrading Methyl Blue (MB) dye under green light (8 W) at various catalysis concentrations and pH values. Within 4 h, 98 % efficiency was achieved using a low amount of 0.01 gm catalyst with 1 ml H 2 O 2 at a pH of 12. The pseudo-first-order reaction rate constant (K app ) revealed that no reaction occurred between MB and catalyst. Density functional techniques (DFT/B3LYP) with the LANL2MB basis set were used to calculate the energies, geometric structure, and vibrational numbers of MoS 2 and γ-Fe 2 O 3 @Au. DFT was used to extract the basic vibrational wavenumbers, intensities, and the shifting of energy levels for each step in the photodegradation reaction. A good agreement was found between the experimental and theoretical results. [ABSTRACT FROM AUTHOR]