Anodic films were grown on Weathering Steel by potentiostatic polarization in slightly alkaline solution. The photoelectrochemical results reveal that they are n-type iron oxide with E_g = 2.0 eV. Rust layer grown by atmospheric corrosion are n-type semiconductors with a band gap higher than that estimated for the anodic film attributed to the formation of γ-lepidocrocite. The electrochemical impedance spectra allow to evidence that rust layers have a higher conductivity with respect to anodic films due to the presence of highly doped iron oxide layers. The use of Mott-Schottky theory to model the dependence of oxide capacitance as function of potential is critically discussed.

通过在弱碱性溶液中通过恒电位极化在耐候钢上生长阳极膜。光电化学结果表明，它们是E- _g  = 2.0 eV的n型氧化铁。通过大气腐蚀而生长的锈层是n型半导体，其带隙高于因形成γ-锂蒙脱石而估计的阳极膜带隙。电化学阻抗谱可以证明由于高掺杂氧化铁层的存在，锈层相对于阳极膜具有更高的导电性。严格讨论了使用Mott-Schottky理论对氧化物电容与电势的函数关系建模的问题。