Photoelectrochemical properties of polypyrrole/TiO2 nanotube arrays nanocomposite under visible light

In this study, different amount of polypyrrole (PPy) were electropolymerized on highly ordered TiO2 nanotube arrays (TiO2NTs) anodized by Ti foil in aqueous solution containing fluoride. In order to improve the conductivity of PPy, an anionic surfactant sodium dodecyl benzene sulfonate (SDBS) was used as doping during electropolymerization. The PPy modified TiO2NTs was confirmed by scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FTIR) and UV–vis spectroscopy (UV–vis). The results indicated that there might exist a strong interaction between TiO2NTs and PPy. Photoelectrochemical response showed that PPy/TiO2NTs electropolymerized for 30 s presented the maximum IPCE 1.81% under 550 nm visible light. The results were ascribed to the presence of narrow band gap p-type conducting polymer semiconductor PPy enhancing visible-light absorption and decreasing the recombination of photo electron–hole result in enhanced photocurrent. These results have implications for the use of PPy/TiO2NTs as a photoswitch or solar cell.