TiO2 nanorod arrays on the conductive mica combine photoelectrochemical cathodic protection with barrier properties

Oriented rutile TiO2 nanorod arrays (TiO2 NRA) were elaborately grown on the conductive mica (C-mica) with Sb-SnO2 seed crystal by a hydrothermal strategy to achieve TiO2 NRA/C-mica composites. The as-obtained samples were characterized by X-ray diffraction, field emission scanning electron microscope, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance spectroscopy and photo-electrochemical measurements. Compared with TiO2 NP/mica, TiO2 NRA/C-mica coated film exhibits more excellent physical barrier ability in the dark, and an enhanced photo-induced current density as well as a more negative photo-potential shift in the light, indicating remarkable photo-cathodic protection for 304 stainless steel (304SS). The distinctive 1D-2D architecture of TiO2 NRA/C-mica facilitates the transmission and separation of photo-induced electron-hole pairs. Furthermore, it's the first time that the TiO2 NRA/C-mica hybrid film is found to possess continuous and stable cathodic protection for the 304SS over a long period in the dark.