Novel polypyrrole-sensitized hollow TiO2/fly ash cenospheres: Synthesis, characterization, and photocatalytic ability under visible light

The polypyrrole-sensitized TiO2 layer on fly ash cenosphere (PPy–TiO2/FAC) was successfully prepared as a promising photocatalyst with visible light response. Photocatalytic activity and kinetics of PPy–TiO2/FAC under visible light were detected in details from aspects of different dopant concentration of HCl and different pyrrole (Py)/Ti molar ratio by detecting photodegradation of methylene blue (MB) and phenol, respectively. It was found that the decomposition rate increased with the increasing Py/Ti molar ratio up to an optimal value, beyond which the photocatalytic activity showed a decreasing tendency. The concentration of HCl in the preparation of PPy–TiO2/FAC also largely influenced the photodecomposition rate of target contamination. The results demonstrate that when the molar ratio of Py/Ti is 1% and the concentration of HCl is 1 mol L−1, the synthesized photocatalyst showed the best photocatalytic activity under visible light.