N-CQDs accelerating surface charge transfer of Bi4O5I2 hollow nanotubes with broad spectrum photocatalytic activity.

Novel N-doped carbon quantum dots (N-CQDs) modified Bi 4 O 5 I 2 hollow nanotubes photocatalysts have been prepared for the first time. Bi 4 O 5 I 2 nanomaterials with hollow nanotube structure were designed to shorten the charge carriers’ migration distance from bulk phase to surface while the N-CQDs was modified to accelerate the surface charge transfer. Multiple characterization methods have been applied to explore the phase structure, elemental composition, optical absorption properties and photocatalytic performance of as-prepared N-CQDs/Bi 4 O 5 I 2 composites. The N-CQDs/Bi 4 O 5 I 2 -0.2 composite showed higher photocatalytic activity for the removal of bisphenol A than pure Bi 4 O 5 I 2 hollow nanotube under UV light, visible light, light above 580 nm, which exhibited the broad spectrum photocatalytic activity. ESR analysis demonstrated the N-CQDs modification can tune the concentration of reactive oxygen species (•OH and •O 2 − ). Combined with free radical trapping experiment results, hole, •OH and •O 2 − were demonstrated to be the main active species and synergistically promoted the enhancement of photocatalytic activity for N-CQDs/Bi 4 O 5 I 2 composite. [ABSTRACT FROM AUTHOR]