Study on the Photocathodic Protection of Q235 Steel by CdIn2S4 Sensitized TiO2 Composite in Splash Zone

In this work, the photo-catalytic activity of TiO2 is considerably enhanced via sensitization with CdIn2S4, and its application for protecting Q235 from corrosion in splash zones is examined. TiO2 nanotube arrays (NTAs) are prepared on a flat Ti substrate via two-step anodization. CdIn2S4 is deposited on the surface of TiO2 NTAs by hydrothermal reaction. TiO2 NTAs with enormous specific surface areas and large-diameter hollow nanostructures are found to benefit the immobilization of CdIn2S4. As a narrow band gap semiconductor, CdIn2S4 is able to extend the light absorption range of TiO2, and the construction of an n–n type hetero-junction accelerates the separation of carriers. Strong solar light, which accelerates the corrosion of Q235 in the splash zone area, is converted into the necessary condition for protecting Q235 from corrosion. In this work, TiO2 is sensitized with MoS2 microspheres (MoS2/TiO2 nanocomposites), which were prepared on a flat Ti substrate via a two-step anodization and hydrothermal method, sequentially.