This study has explored the visible-light illumination promoted corrosion behavior of weathering steelin simulated marine atmospheric condition. Open circuit potential measurements supplied a directinsight on this photovoltaic effect. To obtain better understanding on this process, the correspondingsurface electronic properties together with its microstructures and chemical composition variationswere characterized by Mott-Schottky analysis, AFM, XPS and confocal Raman microspectroscopy.All these combined results revealed that the rusted weathering steel sample collected in the darkdisplayed n-type photo-response due to the presence of hematite (-Fe2O3), maghemite (- Fe2O3),lepidocrocite (-FeOOH) and goethite (-FeOOH) on its surface. Whereas under illumination, thephotogenerated electron-hole pair not only facilitated anodic dissolution and chloride ion adsorptionbut also leading to hematite to magnetite (Fe3O4) transformation in the metal/corrosion layer interface.
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