Significantly activated persulfate by novel carbon quantum dots-modified N-BiOCl for complete degradation of bisphenol-A under visible light irradiation

The practical application of bismuth-based photocatalysts in the field of micropollutant photodegradation is limited due to their weak light absorption and rapid charge recombination. Herein, we have developed a novel carbon quan-tum dots-modified N-BiOCl (CDs-N-BiOCl) photocatalyst to activate persulfate (PS) for the complete elimination of endocrine-disruptor bisphenol A (BPA) under visible light irradiation. The photoelectric properties characterization shows that N atoms could replace Cl atoms or adsorb on Bi atoms to form local N 1s states in the BiOCl lattice, accom-panied by the introduction of doping energy levels that shorten the electron migration distance. Meanwhile, the dec-orated CDs could effectively accept the photoinduced electrons from N-BiOCl conduction band to facilitate the charge separation. Thus, the 7%CDs-N-BiOCl (7CNB) nanocomposite synergistically activated PS realized rapid and effective degradation of BPA within 20 min (degradation efficiency and mineralization reached 100 % and 66.4 % respectively). Moreover, the 7CNB/PS system displayed favorable adaptability, durability, and interference resistance. Furthermore, the biotoxicity experiments demonstrated that the photodegradation intermediates promoted the growth of Escherichia coli which indicates its eco-friendliness for practical application. Finally, the electron transfer mechanism and the for-mation of reactive oxygen species in the photodegradation process were interpreted. In short, this work will present a promising strategy for bismuth-based photocatalysts to be used for the efficient treatment of real water bodies under visible light irradiation.

Automated summary

In this study, a novel carbon quantum dots-modified N-BiOCl photocatalyst was developed to activate persulfate for efficient degradation of bisphenol A (BPA) under visible light irradiation. The introduction of N atoms and decorated carbon quantum dots improved the photoelectric properties of N-BiOCl, facilitating charge separation and electron migration. The 7% CDs-N-BiOCl nanocomposite synergistically activated PS and achieved rapid and effective degradation of BPA, with degradation efficiency and mineralization reaching 100% and 66.4%, respectively. The system displayed good adaptability, durability, and interference resistance, and the photodegradation intermediates promoted the growth of Escherichia coli, indicating its eco-friendliness for practical application.