Fabrication of graphene films on TiO2 nanotube arrays for photocatalytic application

Graphene film was formed on the surface of titanium dioxide nanotube (TiO2 NT) arrays through in situ electrochemical reduction of a graphene oxide dispersion by cyclic voltammetry. The residual oxygen-containing groups and other structural defects such as sp3-hybridized carbons in the electrodeposited graphene were further removed by photo-assisted reduction of the underlying TiO2 NTs, thus achieving the maximum restoration of π-conjugation in the graphene planes. Spectroscopic, electrochemical, and photoelectrochemical techniques were used to characterize the graphene films, and the use of the resulting graphene–TiO2 NT material in photocatalysis was investigated. The results showed that the graphene–TiO2 NT material exhibited a greatly improved photocatalytic activity compared with unmodified TiO2 NTs.