Preparation of CdSe/graphene/TiO₂ Nanotube Composite and Its Protection Properties for Metals

The composite of CdSe/graphene/TiO2 nanotube film was fabricated by cyclic voltammetric deposition of graphene and CdSe on the surface of TiO2 prepared by anodic oxidation process. The composite was characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), UV-visible diffuse reflectance spectra (UV-vis DRS). The photocathodic protection properties of the composite for 304 stainless steel were examined by the open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS). It′s shown that the anatase TiO2 nanotube films were arranged closely and the diameter ranged from 30 to 60 nm. Graphene and cubic CdSe covered the TiO2 evenly and distributed on the mouth and walls of the nanotube arrays. Under visible light illumination, the OCP of the 304 stainless steel coupled with the composite film dropped from -180 mV to -900 mV (SCE). Compared with pure TiO2, the photopotential of the composite film was more negative. When the light was cut off, the photocathodic protection of the composite could maintain more than 12 h. It indicates that this can solve the recombination of photoinduced electrons and holes within the TiO2 film.