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

Abstract

• FCNT-Bi 2 O 2 CO 3 /30% g-C 3 N 4 S-scheme heterostructure was easily prepared by one-step hydrothermal method. • The exposure of crystal planes and bulk defects improve the degradation performance of organic pollutant. • The actual water matrix (such as the Yangtze River and the Yellow River) has little effect on FCNT-Bi 2 O 2 CO 3 /30% g-C 3 N 4 . Appropriate interfacial contact and defect engineering in heterojunction materials play a critical role to improve photocatalytic activity. In this article, a carbon bridge connected Bi 2 O 2 CO 3 /g-C 3 N 4 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-Bi 2 O 2 CO 3 /30% g-C 3 N 4 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-Bi 2 O 2 CO 3 /g-C 3 N 4 step-scheme heterojunction photocatalysts exhibited better activity than pure g-C 3 N 4 and Bi 2 O 2 CO 3 . 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.