关键词: 低碳钢, 纳米TiO₂ 涂层, 形貌, 光电化学, 腐蚀防护

Abstract:

Nano-sized titanium dioxide coatings were prepared on low carbon steel after alkaline blackening and heat treatment via the sol-gel method. The structure, morphology and composition of the prepared coatings were then characterized by means of SEM, XRD and XPS, and the corrosion resistance of the coatings was investigated via the electrochemical method. SEM results indicate that the coatings look blue-grey with many small size-variable cracks and fractures on the surface, XRD spectra show that the coatings are of the anatase structure, and XPS resuits indicate that the coatings are mainly composed of Ti, Fe, O and C. Moreover, the tested results of stable potential and Tafel curves demonstrate that the nano-sized TiO₂ coatings, which protect the low carbon steel from corrosion, are of better photo-electrochemical properties in 2.5% NaHCO₃ solution than in 3% NaCl solution.

Key words: low carbon steel, nano-sized titanium dioxide, coating, morphology, photo-electrochemistry, corrosion protection