Hydrogenated TiO2 nanotube arrays with enhanced photoelectrochemical property for photocathodic protection under visible light

Abstract The hydrogenated TiO2 nanotube arrays (H-TiO2 NTs) were prepared by annealing anodized TiO2 NTs in hydrogen atmosphere, and then used as photoanodes for photocathodic protection of 304 stainless steel (304SS) under visible light and simulated solar light. The effects of hydrogenated temperature and time on the photoeletrochemical (PEC) performance of H-TiO2 NTs were studied in details. The PEC tests showed that the photocurrent density of H-TiO2 NTs was up to 270.8 μA/cm2 and 1.20 mA/cm2 under visible and simulated solar light with good stability, which is about 23 times and 4.5 times than that of pristine TiO2 NTs. Furthermore, photo-induced open circuit potential (OCP) and Tafel curves were measured to evaluate the photocathodic protection effect of H-TiO2 NTs. Salient visible light responses and sharp decline of the OCP made H-TiO2 NTs a promising photocathodic protection material and could be applied to protect the coupled 304 stainless steel from corrosion.