Removal of phenol in seawater by heterogeneous photocatalysis using activated carbon materials modified with TiO2

Abstract

In this work composites based on Activated Carbon (AC) and TiO2 were synthesized by sol-gel method (containing 10 and 20 of TiO2, w%) using glycerol as source of carbon. These materials were used as photocatalysts for the removal of phenol in seawater. The photocatalysts were characterized by: Adsorption-Desorption of N2, Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Infrared Spectroscopy (FTIR), and X-Ray Photoelectronic Spectroscopy (XPS). The photocatalytic test were carried out under UV-C light (254 nm) and Visible light (320−700 nm). The AC-TiO2 composites showed a high surface area, in special AC which reported 1900 (m2. g−1). The TiO2 contained in the composites corresponds to the crystalline form of Anatase. The addition of TiO2 to AC sensitized the material. The AC-TiO2 composites are good photocatalyst for the removal of phenol in seawater, they were superior to the commercial TiO2 (in both situation: under UV and Visible light). The presence of salts of seawater did not affect the heterogeneous photocatalysis under UV light, significantly; moreover, it was benefic under Visible light. In the photocatalysis, the best AC-TiO2 composite removed up to 70 mg of phenol.gcat−1 under UV-C light, and 55 mg of phenol.gcat−1 under Visible light. According to our results, the AC-Ti composites showed promising properties for applications in the removal of organic compounds in seawater. The mechanism, photocatalyst reuse, the effect of scavenger and seawater salts are discussed.