Modification of TiO2 nanorod arrays by graphite-like C3N4 with high visible light photoelectrochemical activity

TiO2 nanorod arrays were modified with graphite-like carbon nitride (g-C3N4) by chemical vapor deposition using melamine as a precursor. The prepared g-C3N4/TiO2/FTO was characterized by scanning and transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV–vis and photoluminescence spectroscopy for comprehensive morphological, structural, and photoelectrical properties. Electrochemical investigation reveals that modification of TiO2 by g-C3N4 dramatically improves the electron-transfer rate from electrolyte to the electrode surface and the flat band potential of the electrode shifts to a more negative potential with enhanced donor density. The g-C3N4/TiO2/FTO electrode also shows high photoelectrocatalytic activity towards degradation of rhodamine B. Under visible light irradiation, the photocurrent response of the g-C3N4/TiO2/FTO electrode is about 10 times as that of the TiO2/FTO electrode, which makes it a promising nanomaterial for future applications in solar cells, water treatment and photoelectrical devices.

► Vertically aligned TiO2 nanorods were grown on FTO by hydrothermal synthesis.
► The TiO2 nanorods were modified by g-C3N4 to construct g-C3N4/TiO2 heterojunction.
► The photocurrent of the g-C3N4/TiO2/FTO is 10 times as that of the TiO2/FTO.
► High photoelectrocatalytic activity for degradation of Rh B.
► Effective separation of photogenerated electron-hole pairs.