Morphology effects of in situ hydrothermally treated hierarchical TiO2 nanofilms on their photoelectrochemical cathodic protection performance against 304 stainless steel corrosion

Various TiO 2 nanofilms with nanosheet, nanosheet–nanowire hybrid, and nanowire nanostructures were successfully achieved through an in situ hydrothermal alkali-etching method. The effects of the TiO 2 film structures on their photoelectrochemical cathodic protection performance against 304 stainless steel corrosion were evaluated. Characterization results show that the as-prepared TiO 2 films exist mainly as anatase crystals and that TiO 2 nanowire films display high light absorption intensity, low fluorescence intensity, and great carrier density. After coupling with TiO 2 nanowire films, the corrosion potential of 340SS presents the most negative shift from − 0.216 V vs. SCE to − 0.306 V vs. SCE, and the photopotential and the photocurrent density display the largest response of − 0.284 V and 0.22 mA cm −2 . The nanowire structure enhances light scattering and trapping for efficient solar light harvesting. Graphical abstract