Ameliorative photocatalytic dye degradation performance of ternary Co3O4/MoS2/TiO2 nanocomposite under visible light illumination

Background: This research aimed to synthesize a novel ternary nanohybrid material, Co3O4/MoS2/TiO2 (CMT), to
enhance photocatalytic degradation of methylene blue (MB) under light irradiation. Conventional photocatalysts
often suffer from limited efficiency, so integrating Co3O4, MoS2 and TiO2 aimed to overcome these challenges by
improving charge transfer and separation of electron-hole (e⁻/h⁺) pairs.
Methods: The CMT nanocomposites were synthesized using calcination and hydrothermal methods. Various
spectroscopic and microscopic techniques were employed to characterize the CMT nanocomposites, and their
photocatalytic activity was evaluated by testing MB degradation efficiency. Kinetic studies were also performed
to assess the reaction rate, while the material’s stability was tested over five degradation cycles.
Significant findings: The CMT nanocomposites demonstrated remarkable photocatalytic performance, achieving
94.77 % MB degradation, outperforming other materials. The kinetic rate constant was 0.0181 min⁻1, 4.02 times
higher than alternative samples. Enhanced charge transfer between Co3O4 and the other components contributed
to efficient e⁻/h⁺ pair separation. The photocatalyst remained stable over repeated use, and superoxide radicals
(•O2⁻) were identified as the dominant reactive species during MB degradation, highlighting the material’s ef
ficiency and durability.