Abstract: Novel nanocomposites of TiO₂ and two kinds' carbon nanofibers with different microstructure were prepared by sol-gel method. The nanocomposites were studied via SEM, XRD, and photoelectrochemistry. The potential dependence of photocurrent and the photocurrent transients indicate that the nanocomposite shows characteristics of n-type semiconductor. The experimental results demonstrate that the PCNF/TiO₂ shows a higher photoelectrochemical response and sensitivity for visible light illumination than FCNF/TiO₂ and pristine TiO₂. This is likely because of the specific microstructure of the PCNF, which possesses large numbers of active edge sites and provides many favorable sites for electron transfer as well as a very large working surface area. The significant enhancement of the photoelectrochemical response of the CNF toward visible light responses may result from the difference of their morphologies as well as their textural properties and crystalline structure. The results show that PCNF and FCNF are thus very promising candidates for developing a class of ideal and novel modified photoelectrodes.

Key words: TiO₂ nanocomposite electrodes, Carbon nanofibers, Photoelectrochemistry, IPCE