REDOX REACTIONS AND MAIN CARRIERS IN MILL SCALES OF REBARS

Raman spectroscopy, XRD, backscattered electronic images and Mott-Schottky plots were used to explore the redox properties and charge transport characteristics in mill scales of rebars in saturated Ca(OH)₂ solution. The results showed that mill scales of rebars could be inwardly oxidized during anodic polarization, and the Fe₃O₄ in the surface layer of the mill scale was transformed into α-Fe₂O₃. Reduction happened when it was cathodically polarized, and the α-Fe₂O₃ in the skin layer disappeared. No new phase was found at the matrix-scale interface. Rebars with mill scales had an n-type semiconductor transporting characteristics in saturated Ca(OH)₂ solution and the main carriers were interstitial iron ions.