Long-Term Dual Cathodic Protection for Q235 Carbon Steel by Co(OH)2/Graphene/TiO2Photocatalytic Material and Traditional Sacrificial Anode

A novel Co(OH)(2)/graphene/TiO2-Al-Zn-In-Mg-Ti photoanode composite (Al-TGC photoanode) was proposed and fabricated by combining the photocatalytic material with traditional sacrificial anode, aiming to not only prolong the lifetime of traditional sacrificial anode but also make photocatalytic material really applicable in practice. The cathodic protection performance of Al-TGC photoanode and traditional sacrificial anode for Q235 carbon steel (Q235CS) was evaluated by long-term electrochemical experiments and macro corrosion surface morphologies of Q235CS. Results indicated that the new Al-TGC photoanode can provide more effective cathodic protection for Q235CS at least for 30 d in 3.5 wt% NaCl solution, which is obviously better than that of a traditional sacrificial anode and an older Al photoanode composite. In this new material system, graphene plays a very important role in increasing the long-term stability and lifetime of the Al-TGC photoanode.