Synthesis of polypyrrole‐modified TiO 2 composite adsorbent and its adsorption performance on acid Red G

The adsorption–desorption characteristics of Acid Red G (ARG) on the polypyrrole‐modified TiO 2 (PPy/TiO 2 ) composite as a novel adsorbent was investigated. PPy/TiO 2 was synthesized via the in‐situ polymerization of pyrrole monomer in the prepared TiO 2 sol solution. Results from X‐ray diffraction and Fourier transform infrared spectra indicated the formation of the PPy/TiO 2 composite. The adsorption experiments showed that the modification of PPy substantially improved the adsorption and regeneration abilities of PPy/TiO 2 . The adsorption equilibrium was achieved in a short time of 20 min, and the adsorption kinetics followed the pseudo‐second‐order model. The Langmuir adsorption isotherm was found for PPy/TiO 2 , with the maximum adsorption capacity of 179.21 mg/g. The regeneration experiments showed that PPy/TiO 2 could be successfully regenerated by simple alkali‐acid treatment. The adsorption efficiency of the regenerated PPy/TiO 2 adsorbent for ARG was still greater than 90% after regeneration for 10 times. Additionally, the adsorption efficiency of PPy/TiO 2 for the ARG effluent was still higher than 78% after adsorption–desorption for four times. It is expected that the PPy/TiO 2 composite can be considered as a stable adsorbent for the removal of dye. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013