Oxygen vacancy semiconductor: an additive to improve corrosion protective performance significantly

Semiconductors, based on their unique properties, are widely used in various fields such as in sensors, information and energy technologies, which are usually contact with metallic substances. Among them, oxygen vacancy semiconductors have a wide range of applications such as oxygen sensors, transparent electrodes, and oxygen separation membranes. Herein, the effect of oxygen vacancy semiconductor on facilitating the dense oxide layer formation at its metal interface was demonstrated, which might have a profound effect on many related areas. Corrosion of metal not only causes tremendous economic loss, but also leads to structural failure that brings about catastrophic consequences to human society and environment. In this manuscript, black TiO2 (BT) nanowires, a model of oxygen vacancy semiconductor, were prepared by chemical reduction of white TiO2 (WT) nanowires with NaBH4 and served as an additive in epoxy coatings to protect the metal substrates. The experimental results demonstrate that coatings containing BT nanowires exhibit superior ability to ordinary TiO2 nanowires in the formation of dense oxide layer at the steel/coating interface. Finally, the experimental results were discussed and the mechanism was proposed.