Functionalized carbon nanotube bridge interface drove Bi2O2CO3/g-C3N4 S-scheme heterojunction with enhanced visible-light photocatalytic activity

Abstract Appropriate interfacial contact and defect engineering in heterojunction materials play a critical role to improve photocatalytic activity. In this article, a carbon bridge connected Bi2O2CO3/g-C3N4 step-scheme heterojunction photocatalysts were fabricated by a simple one-step hydrothermal method. Among them, the functionalized carbon nanotube as a bridge has excellent electrochemical energy storage performance and favorable stability. Under visible light irradiation, the FCNT-Bi2O2CO3/30% g-C3N4 exhibited the best photocatalytic activity for the degradation tetracycline with 96%. The enhanced photocatalytic activity could be due to the doping of acidified nanotubes causing shallow potential defects in the heterostructure, exposing the {0 0 1} crystal plane and causing bulk defects, which in turn facilitate the separation of photogenerated charge carriers. Moreover, the obtained FCNT-Bi2O2CO3/g-C3N4 step-scheme heterojunction photocatalysts exhibited better activity than pure g-C3N4 and Bi2O2CO3. In addition, the formation and practical application of composite heterostructures are discussed in detail. This investigation provides new insight for designing and constructing novel S-scheme heterojunction photocatalysts.