关键词: TiO2, 聚苯胺, 光电化学

Abstract: A TiO 2 and polyaniline (PANI) composite film was obtained by electrochemical methods. The SEM image of the composite film showed that the PANI film is almost completely covered with TiO 2. The spectra of photocurrent for the TiO 2 PANI composite film , which overlaps the TiO 2 film and PANI film, showed that the composite film is able to have higher conversion efficiency. The spectra of photocurrent for the TiO 2 PANI composite film were different from these of TiO 2 film photosensitized by PANI. The bandgap energy of TiO 2 film on partially oxidized PANI film was determined as 3.0 eV by the threshold energy of photocurrent band for TiO 2. The spectra of photocurrent for partially oxidized PANI film electrode suggested that it has the characteristics of sub band gap spectra of photocurrent and followed Fowler rule(  1/2 ～hν) . The bandgap energy of insulating matrix in partially oxidized PANI is determined as 3.33 eV by the Flowler plots, and the insulating matrix in partially oxidized PANI was verified to be reduced PANI. The flat band potentials, in the order of 0.87 V vs. NHE for partially oxidized PANI and 0.09V vs. NHE for TiO 2 PANI composite film in 1.0 mol/L HClO 4 solution,were obtained from Mott Schottky plots. The doping content of partially oxidized PANI and TiO 2 PANI composite film are 5.3×10 18 cm -3 and 9.1×10 19 cm -3 , respectively. The photoelectrochemical process of TiO 2 PANI composite film is interpreted and the energy diagram is proposed. The TiO 2 PANI composite film can be well used for treating the wastewater, for example, containing phenol.

Key words: TiO 2, Polyaniline, Photoelectrochemistry