Internal photoemission in polyaniline
- 化学化工－已发表论文 
After self-assembling a p-aminothiophenol(PATP) monolayer on bare Au electrode, polyaniline (PANI) films were prepared by electropolymerization on the modified Au electrode and three forms of PANI (reduced PANI, partially-oxidized PANI and oxidized PANI) were obtained by electrochemical method. The SEM pattern shows that there are some hills of PANI on a compact layer of PANI. The cyclic votammograms of the probe [K3Fe (CN)(6)/K4Fe (CN)(6)] for the three forms of PANI film show that partially-oxidized PANI has a good electron transport performance. The potential dependence of magnitude and spectra of the photocurrent of PANI films were observed. The bandgap energy of 1.45 eV for oxidized PANI, which is the threshold energy of its photocurrent spectra, was obtained. The spectra of photocurrent for partially-oxidized PANI film shows that it has the characteristics of sub-band gap photocurrent spectra and follows Fowler rule (IPCE(1/2)similar tohnu). 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 is verified to be reduced PANI. The flat-band potential, in the order of 0.63 V vs. SCE, is obtained from Mott-Schottky plots. A photoelectrochemical process based on internal photoemission in partially-oxidized PANI, which agrees with the model of granular metal island that assumes metallic polymer particles are embedded in the insulating matrix, is proposed.