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

• Published in: Applied catalysis. B, Environmental Environmental, 2018-12, Vol.237, p.1033-1043
• Main Authors: Ji, Mengxia, Liu, Yiling, Di, Jun, Chen, Rong, Chen, Zhigang, Xia, Jiexiang, Li, Huaming
• Format: Article
• Language: English
• Subjects: Bi4O5I2 hollow nanotube; BPA removal; Charge separation; N-CQDs; Photocatalytic
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2018.06.014

A novel N-doped carbon quantum dots (N-CQDs) modified Bi4O5I2 hollow nanotubes photocatalyst was prepared for the first time. The N-CQDs/Bi4O5I2 composite showed higher photocatalytic activity for the removal of BPA than pure Bi4O5I2 hollow nanotube under UV light, visible light, light above 580 nm, which exhibited the broad spectrum photocatalytic activity. [Display omitted] •Novel N-doped carbon quantum dots (N-CQDs) modified Bi4O5I2 hollow nanotubes composite photocatalysts have been prepared successfully for the first time.•The N-CQDs/Bi4O5I2-0.2 composite exhibited excellent broad spectrum photocatalytic activity for BPA removal.•Hollow nanotube structure shortened the charge carriers’ migration distance from bulk phase to surface in Bi4O5I2 while the N-CQDs accelerating the surface charge transfer.•The holes, •OH and O2− are determined to be the dominant species for the degradation of organic pollutants. Novel N-doped carbon quantum dots (N-CQDs) modified Bi4O5I2 hollow nanotubes photocatalysts have been prepared for the first time. Bi4O5I2 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/Bi4O5I2 composites. The N-CQDs/Bi4O5I2-0.2 composite showed higher photocatalytic activity for the removal of bisphenol A than pure Bi4O5I2 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 •O2−). Combined with free radical trapping experiment results, hole, •OH and •O2− were demonstrated to be the main active species and synergistically promoted the enhancement of photocatalytic activity for N-CQDs/Bi4O5I2 composite.