レーザー脱不働態化技術による過塩素酸溶液中における鉄の再不働態化挙動

抄録

The laser impact technique has been applied to the activation of passivated iron for the investigation of the repassivation kinetics combined with a channel flow double electrode (CFDE). The amount of ferrous ion dissolved from the activated iron electrode during repassivation was detected with the CFDE system. The total charge for repassivation, Q_w, was separated into the partial charges for dissolution of ferrous ion, Q_diss, and formation of adsorbed species, Q_f. The Q_diss decreases with increasing electrode potential. On the other hand, the Q_f does not depend on the electrode potential, and its value corresponds to the formation of a monolayer of trivalent oxide film. The numerical simulations for repassivation of iron were performed under a reaction model involving two adsorbed species, and their results were in good agreement with the experimental ones. The actual repassivation rate was characterized by the surface coverage of passivating adsorbed species, θ₂(t).