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Abstract: Nanocrystalline mesoporous titania was synthesized via a combined sol–gel process with surfactant-assisted templating method using cetyltrimethyl ammonium bromide (CTAB) as the structure-directing agent. The process was catalyzed by different acid (hydrochloric acid, nitric acid, sulfuric acid, or phosphoric acid). The prepared samples were characterized by XRD, TEM, BET and FT-IR. The photocatalytic activity of the samples was determined by degradation of phenol in aqueous solution. Results showed that different acid had different effect on the structure and crystal phase of the samples. The sample adjusted by phosphoric acid showed highest surface area and photocatalytic activity. The formation mechanism of the samples catalyzed by different acid was also discussed. [Copyright &y& Elsevier]

Polyaniline (PANI) modified mesoporous single crystal TiO 2 microsphere (PANI/MS-TiO 2 ) with excellent photocatalytic activity was successfully prepared by a simple method of solution evaporation and chemisorption. The X-ray diffraction characterization demonstrated that the whole MS-TiO 2 kept the crystal type of anatase. The nitrogen adsorption-desorption characterization coupled with scanning electron microscopy indicated that the MS-TiO 2 possessed a unique mesoporous structure with high specific surface area, which resulted in the increased load of PANI on the surface of MS-TiO 2 and multiple light reflection in the photocatalyst. The UV–vis diffuse reflectance spectra confirmed that PANI/MS-TiO 2 presented more absorption ability in the visible light range than that of the pristine MS-TiO 2 . The transient photocurrent responses and electrochemical impedance spectroscopy (EIS) indicated the high photo responses and fast photogenerated charge separation efficiency of PANI/MS-TiO 2 . The photocatalytic activity of the PANI/MS-TiO 2 was evaluated by the photodegradation of RhB and MB under visible light irradiation. MS-TiO 2 photocatalyst with different molar ration of PANI had been prepared, and the results showed that the optimal photocatalyst (PANI/MS-TiO 2 (1:40)) exhibited the highest photocatalytic efficiency which is nearly three times as great as that of pristine MS-TiO 2 for the degradation of the RhB and MB under visible light irradiation. The remarkable performance of the PANI/MS-TiO 2 under visible light was attributed to its mesoporous single crystal structure with large surface, conductivity, as well as the synergistic effect between PANI and MS-TiO 2 . [ABSTRACT FROM AUTHOR]