A Novel Photocatalyst Composite of Magnesium Aminoclay and TiO₂ Immobilized into Activated Carbon Fiber (ACF) Matrix for Pollutant Removal.

Titanium dioxide (TiO₂) is a semiconductor photocatalyst widely applied in numerous fields due to possessing prominent photocatalytic properties. However, its practical applications in the form of nanoparticles or powders still have remained several limitations. Recently, novel photocatalytic porous composites have been discovered to be potential alternative approaches. In the present study, nanostructured magnesium-aminoclay-based TiO₂ (MgAC-TiO₂) was successfully deposited on an activated carbon fiber (ACF) matrix using the sol-gel approach followed by calcination at 350°C in an air atmosphere. The structure and photocatalytic activity of this as-prepared photocatalyst composite were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), the Brunauer-Emmett-Teller (BET), and UV-vis diffuse reflectance spectral analysis. The photocatalytic activity of MgAC-TiO₂/ACF was investigated under batch conditions for the removal of methylene blue (MB) in solution under UV irradiation and dark conditions. The results revealed that MB is absorbed by MgAC-TiO₂/ACF and that its photodecomposition occurs under UV irradiation. The addition of MgAC can prevent the sintering of TiO₂ act as a dispersing agent to create a high specific surface area, and thus enhance photocatalytic efficiency. In addition, ACF in the MgAC-TiO₂/ACF composite can additionally improve the photocatalytic activity by hindering electron-hole recombination, which is known as a synergetic effect, and thereby enhancing the photodegradation and removal efficiency of MB.