BiSe Sensitized TiO Nanotube Films for Photogenerated Cathodic Protection of 304 Stainless Steel Under Visible Light.

Titanium dioxide (TiO) nanotube arrays coupled with a narrow gap semiconductor-bismuth selenide (BiSe)-exhibited remarkable enhancement in the photocathodic protection property for 304 stainless steel under visible light. BiSe/TiO nanocomposites were successfully synthesized using a simple two-step method, including an electrochemical anodization method for preparing pure TiO and a chemical bath deposition method for synthesizing BiSe nanoflowers. The morphology and structure of the composite films were studied by scanning electron microscopy, energy dispersion spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction. In addition, the influence of the BiSe content on the photoelectrochemical and photocathodic protection properties of the composite films was also studied. The photocurrent density of the BiSe/TiO nanocomposites was significantly higher than that of pure TiO under visible light. The sensitizer BiSe enhanced the efficient separation of the photogenerated electron-hole pairs and the photocathodic protection properties of TiO. Under visible light illumination, BiSe/TiO nanocomposites synthesized by the chemical bath deposition method with Bi (0.5 mmol/L) exhibited the optimal photogenerated cathodic protection performance for 304 stainless steel.