Integration of Adsorption and Photocatalytic Degradation of Methylene Blue Using $$\hbox {TiO}_{2}$$ TiO 2 Supported on Granular Activated Carbon

• DOI: 10.1007/s13369-016-2369-y
• Publication Date: 2016-11-29T16:23:36Z
• Authors: H. Atout; A. Bouguettoucha; D. Chebli; J. M. Gatica; H. Vidal; M. Pilar Yeste; A. Amrane
• Keywords: 02 engineering and technology; 0210 nano-technology

An integrated process was investigated for the degradation of methylene blue (MB); it was based on the combination of adsorption and photocatalysis. A granular activated carbon (C) was considered for adsorption, which involved \(\hbox {TiO}_{2}\) as a photocatalyst (\(\hbox {TiO}_{2}/\hbox {C}\)). The \(\hbox {TiO}_{2}/\hbox {C}\) was directly obtained by an impregnation method using \(\hbox {TiCl}_{3}\); it was also calcined under air atmosphere at \(500\,{^{\circ }}\hbox {C}\) (\(\hbox {TiO}_{2}/\hbox {C}\)-500). These materials were characterized by TGA, BET, SEM, EDS mapping, SEM-EDS, and their \(\hbox {pH}_{\mathrm{{PZC}}}\) were measured. The results obtained showed that activated carbon (C) exhibited the best performances in terms of adsorption. The photocatalytic activity on the degradation of MB in aqueous solution under UV irradiation was tested and compared to that of \(\hbox {TiO}_{2}\) anatase (\(\hbox {TiO}_{2}\, \hbox {A}\)) and a mixture of carbon with \(\hbox {TiO}_{2 }\) (\(\hbox{C--TiO}_{2}\)). \(\hbox {TiO}_{2}/\hbox {C}\)-500 catalyst was found to be more active than the other catalysts; the C with high surface area provided sites for adsorption, allowing the migration of the dye to the surface of \(\hbox {TiO}_{2}\). A synergistic effect between C and \(\hbox {TiO}_{2}\) was shown, which enhanced the photocatalytic activity by retarding the recombination of photogenerated electron–hole pairs, improving light absorption.