Au/PATP/PANI膜电极和Au/PATP/PANI/TiO2膜电极的光电化学

Au/PATP/PANI (polyaniline) film electrode was prepared by voltamometry in 0.5 mol/L aniline/0.5 mol/L HClO 4 from -0.2—0.8 V at 100 mV/s after selfassembling PATP(4aminothiophenol) on bare Au. The potential dependence of photocurrent and the photocurrent spectra of Au/PATP/PANI film electrode were obtained. The potential dependence of photocurrent showed that all of the three forms(oxidized/partiallyoxidized/reduced) of PANI film had both anodic photocurrent and cathodic photocurrent. The halfoxidized PANI film had a great photoelectrochemical response. The photocurrent spectra of Au/PATP/PANI film electrode showed both half oxidized and reduced PANI film had the characteristics of subbandgap photocurrent spectra and followed Fowler rule(IPCE 1/2 =E threshold + b hν ). A photoelectrochemical model on internal photoemission at insulator covered metal was presented to interpret it, which agreed with the model of granular metal island. The model assumed metallic polymer particles embedded in the nonmetallic matrix, while, Au/PATP/PANI/TiO 2 film electrode was prepared by electrodeposition in TiCl 3 solution (pH≈2.2). The photocurrent spectra of Au/PATP/PANI/TiO 2 film possessed the photoelectrochemical characteristics of both TiO 2 and PANI. The Au/PATP/PANI/TiO 2 film was expected to improve the efficient absorption of solar light.