The photoelectrochemistry of Au/PATP/PANI film electrode and Au/PATP/PANI/TiO2 film electrode

Au/PATP/PANI (polyaniline) film electrode was prepared by voltamometry in 0.5 mol/L aniline/0.5 mol/L HClO4 from - 0.2-0.8 V at 100 mV/s after self-assembling PATP(4-aminothiophenol) 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/partially-oxidized/reduced) of PANI film had both anodic photocurrent and cathodic photocurrent, The half-oxidized 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 subband-gap photocurrent spectra and followed Fowler rule (IPCE1/2 = E-threshold + b hv). 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/TiO2 film electrode was prepared by electrodeposition in TiCl3 solution (pH approximate to 2.2), The photocurrent spectra of Au/PATP/PANI/TiO2 film possessed the photoelectrochemical characteristics of both TiO2 and PANI, The Au/PATP/PANI/TiO2 film was expected to improve the efficient absorption of solar light.