Surface treatment of titanium by in-situ anodizination and NiO photodeposition: enhancement of photoelectrochemical properties for water splitting and photocathodic protection of stainless steel

摘要

Chromium-doped TiO_2 nanotubes (CT) film on titanium substrates was prepared by an in-situ electrochemical anodizing method and then a wide range time was used for photodeposition of NiO on the surface of CT to optimize the condition for the fabrication of NiO-chromium-doped TiO_2 nanotubes (NCT). Various techniques were used to characterization which confirms the anatase form of TiO_2 as well as the presence of NiO. The UV-Vis spectra exhibit that deposited of NiO on the surface of CT progressively enhances visible light absorption. Photoelectrochemical performance of as-prepared samples was studied in the presence and absence of light which showed that NCT samples are markedly beneficial for reducing photo generated charges recombination. NCT2 sample effectively increased photocurrent density four times more than the bare CT sample and showed the maximum amount of H_2 evolution during water splitting after 60 min. In addition, Tafel tests are performed to investigate the photocathodic protection of as-prepared samples for 403 stainless steel. It was observed that the photocathodic protection performance is achieved for NCT2 which prepared at a photodeposition time of 20 min.