Design and Application of Homogeneous-structured TiO2/Activated Carbon Nanocomposite for Adsorption–Photocatalytic Degradation of MO

The sol–gel method successfully prepared homogeneous-structured TiO2/activated carbon (TiO2/AC). This study highlights the effect of post-annealing temperature on the properties and photocatalytic activity of composite TiO2/AC to remove methyl orange (MO). The prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), Brunauer–Emmett–Teller measurement (BET), and thermogravimetric (TGA). The results confirmed that all prepared photocatalysts were TiO2 anatase. The removal of MO was obtained through a synergistic effect of adsorption and photocatalysis. TiO2/AC-400 was the optimum photocatalyst to decompose MO up to 80% after 90 min under simulated UV irradiation. The remaining 1% AC after the annealing process at 500 °C had proved to be capable of decomposing MO mainly due to its serving as an electron trap. The potential photocatalyst formation and photocatalysis mechanism for TiO2/AC nanocomposite to support phenomena were proposed. The finding in this study provided important implications for further research on the preparation of composite TiO2 and carbon-based co-catalyst to enhance the adsorption–photocatalytic activity.