Graphene incorporated nanocrystalline TiO_2 films for the photocathodic protection of 304 stainless steel

摘要

Composite films of TiO_2 and graphene (GR) were prepared on 304 stainless steel (304SS) by the sol-gel method and heat treatment. The morphology, crystalline phase, and composition of the GR/TiO_2 films were characterized systematically by X-ray diffraction, Raman spectroscopy and scanning electron microscopy, respectively. The photocathodic protection performances of the composite film under illumination and dark conditions in 3.0% NaCl solution were evaluated through the electrochemical measurements. It is indicated that the incorporation of GR in TiO_2 film can improve effectively the photocathodic protection effect for 304SS under the UV illumination. Compared to 350 mV of pure TiO_2 film, the electrode potentials can be negatively shifted to about -600 mV under UV light irradiation by incorporating GR into TiO_2 films. At the same time, a 14-fold photocurrent density can be obtained for the GR/TiO_2 film. This indicates that GR can play an excellent enhancing effect on the photogenerated cathodic protection of TiO_2 films.