Study of the Effect of TiO₂ Layer on the Adsorption and Photocatalytic Activity of TiO₂-MoS₂ Heterostructures under Visible-Infrared Light

In the last decade, the urgent need to environmental protection has promoted the development of new materials with potential applications to remediate air and polluted water. In this work, the effect of the TiO₂ thin layer over MoS₂ material in photocatalytic activity is reported. We prepared different heterostructures, using a combination of electrospinning, solvothermal, and spin-coating techniques. The properties of the samples were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), nitrogen adsorption-desorption isotherms, UV-Vis diffuse reflectance spectroscopy (UV-Vis-DRS), and X-ray photoelectron spectroscopy (XPS). The adsorption and photocatalytic activity were evaluated by discoloration of rhodamine B solution. The TiO₂-MoS₂/TiO₂ heterostructure presented three optical absorption edges at 1.3 eV, 2.28 eV, and 3.23 eV. The high adsorption capacity of MoS₂ was eliminated with the addition of TiO₂ thin film. The samples show high photocatalytic activity in the visible-IR light spectrum.