The effect of incorporating carbon nanotubes in titania films used for the photocathode protection of 304 stainless steel

Composite films of TiO2 and multiwall carbon nanotubes (MWCNTs) were prepared on 304 stainless steel (304 SS) by the sol–gel method and heat treatment. Their crystal phase and surface structure were characterized by X-ray diffraction and electron microscopy. The photoelectrochemical performance of the composite films in 3.0% NaCl solution was evaluated by electrochemical measurements under UV irradiation and dark conditions. Since highly conductive MWCNTs in the TiO2 films can transport the photo-generated electrons easily and quickly to the metal substrate, the MWCNT/TiO2 composite films exhibited three times the photocurrent and the half the charge transfer resistance of pure TiO2 films, and provide a much better photocathode protection for 304 SS.