Mott-Schottky Investigation of Passivation Film of Rebar in Simulated Concrete Pore Solution

The semiconducive properties of the passive film on rebar in simulated concrete pore solution were analyzed by Mott-Schottky (M-S) plots.The relation of C-2SC-E of rebar electrode showed linear M-S relationship and positive slope within -0.78-0.37 V(SCE),indicating the passivation film on rebar was n-type semiconductor.The capacitance values were frequency dependent and there was a strong dispersion of the M-S plots with frequency.With adding chloride ions in simulated concrete pore solution or prolonging the time of rebar electrode in system,the donor density of film increased.