Covalent Organic Framework Decorated TiO2 Nanotube Arrays for Photoelectrochemical Cathodic Protection of Steel

For the first time, a covalent organic framework TpBD was grown in situ on TiO 2 nanotube arrays (NTAs), and the performance of the composite was investigated for the application of photoelectrochemical (PEC) cathodic protection. The synthesized TpBD/TiO 2 NTA composite exhibited enhanced PEC cathodic protection performance under visible light. Coupled with the TpBD/TiO 2 NTA photoanode, the photoinduced potential drop values for 304 stainless steel and Q235 carbon steel in 3.5 wt% NaCl solution were 910 and 370 mV, respectively. It was proposed that the enhanced PEC performance was due to the formation of a Z-scheme heterojunction between TpBD and TiO 2 .