In this study, two series of CNT/TiO2 electrodes were prepared. The decrease of surface area compared with that of the pristine carbon nanotubes (CNTs) indicated the blocking of micropores on the surface of the CNTs; was further supported by scanning electron microscopy (SEM) and field emission SEM (FE-SEM) observations. The X-ray diffraction (XRD) results showed that the CNT/TiO2 composites contained a mix of anatase and rutile forms of TiO2 particles when the precursor was TiO2 powder, whereas when the precursor was Ti (OC4H7) (TNB), the composites contained only the typical single and clear anatase TiO2 particles. The energy dispersive X-ray spectroscopy (EDX) spectra showed the presence of C, O and Ti peaks for all samples. It was found that catalytic decomposition of methylene blue (MB) solution could be attributed to synthetic effects between the TiO2 photocatalysis and electro-assisted CNTs network, and that photoelectrocatalytic oxidation increased with an increase of CNT composition. It was also found that the photoelectrocatalytic oxidation efficiency for MB is higher than that of photocatalytic oxidation. Moreover, the CNT/TiO2 composites catalyst prepared by the impregnation method demonstrates higher photoelectrocatalytic activity than the mechanical mixture with the same CNT content.