Activated carbon (AC) was impregnated with titanium dioxide (TiO2) to synthesize AC/TiO2 nanocomposite through the sol-gel method at 400°C. Nanocomposite characterization was conducted by XRD, SEM and FTIR analyses. The synthesized nanoparticles were phase-pure anatase nanocrystallites with the average size of 10 nm. The AC/TiO2 nanocomposites were applied for the first time to photocatalytic decomposition of Congo red (CR) dye under ultraviolet (UV) irradiation in a photoreactor. The effects of AC/TiO 2 nanocatalyst dosage (0.3–1 g), CR concentration (20–100 ppm), pH (3–9) and temperature (30–50°C) were examined for removal of CR solution pigments. Moreover, the adsorption kinetics and isotherm models were investigated on the AC and synthesized AC/ TiO 2 nanophotocatalyst. The adsorption mechanism was found to be a pseudo-second-order kinetics with the good agreement for both adsorbents. Also the experimental isotherms were appropriately described by the Langmuir and Temkin models for AC adsorbent and AC/TiO2 nanocomposite, respectively.
