CdTe/TiO₂ nanocomposite material for photogenerated cathodic protection of 304 stainless steel

Graphical abstract: - Highlights: • The photoelectric properties of TiO₂ could greatly improve by doping with CdTe. • The cathodic protection property of the CdTe/TiO₂ was superior to that of pure TiO₂. • The protective action of the CdTe/TiO₂ for 304SS could be maintained in the dark. - Abstract: TiO₂ nanotubes were fabricated by the anodization method, and CdTe was deposited on them via electrochemical deposition method. The optimal performance of the CdTe/TiO₂ composites was achieved via changing the acidity of the electrolyte. Scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction were used to investigate the surface morphology, elemental analysis and phase characteristics of the composite materials. Some electrochemical tests, such as open-circuit potential, current variation versus time were carried out to investigate the photogenerated cathodic protection of 304 stainless steel by CdTe/TiO₂. The results indicated that the cathodic protection performance of the CdTe/TiO₂ composite was superior to that of pure TiO₂ in the wavelength of visible light. The CdTe/TiO₂ composite exhibited optimal photogenerated cathodic protection properties under visible light for the corrosion potential of 304 stainless steel shifted negatively to −850 mV when the concentration of HCl in the deposition electrolyte was 1 mol/L.