TiO_2聚苯胺复合膜的光电化学

利用电化学方法制备了TiO2 聚苯胺 (PANI)复合膜 .该膜具有比TiO2 或PANI膜更宽的吸收谱区 ,并且不同于利用聚苯胺光敏化的TiO2 膜 ,表现为两者复合材料膜的性质 .扫描电镜图表明 ,TiO2 微粒不完全覆盖着PANI膜 .根据TiO2 微粒光电流谱带的阈值能可得复盖在部分氧化态聚苯胺膜上的TiO2 微粒的禁带宽度为 3.0eV .部分氧化态聚苯胺膜的光电流谱遵循Fowler定律 ( 1/2 ～hυ成线性 ) .通过Fowler图得出部分氧化态聚苯胺的绝缘母体禁带宽度为 3.33eV ,并证实该绝缘母体为还原态聚苯胺 .从Mott Schottky图得到在 0 .0 5mol/LK3Fe(CN) 6 /K4 Fe(CN) 6 溶液中 (pH =8.52 )部分氧化态聚苯胺的平带电位为 0 .13V ,掺杂浓度为 5.3× 10 18cm- 3;TiO2 PANI复合膜的平带电位为 - 0 .6 5V ,掺杂浓度为 9.1× 10 19cm- 3.解释了TiO2 PANI复合膜的光电化学过程并描绘出其能带图 .利用TiO2 PANI复合膜能够有效地光降解苯酚溶液 .

The Photoelectrochemistry of TiO2-Polyaniline Composite Film

A TiO2 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 TiO2. The spectra of photocurrent for the TiO2-PANI composite film , which overlaps the TiO2 film and PANI film, showed that the composite film is able to have higher conversion efficiency. The spectra of photocurrent for the TiO2-PANI composite film were different from these of TiO2 film photosensitized by PANI. The bandgap energy of TiO2 film on partially-oxidized PANI film was determined as 3.0 eV by the threshold energy of photocurrent band for TiO2. 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 TiO2-PANI composite film in 1.0 mol/L HClO4 solution,were obtained from Mott-Schottky plots. The doping content of partially-oxidized PANI and TiO2-PANI composite film are 5.3×1018　cm-3 and 9.1×1019　cm-3, respectively. The photoelectrochemical process of TiO2-PANI composite film is interpreted and the energy diagram is proposed. The TiO2-PANI composite film can be well used for treating the wastewater, for example, containing phenol.