Aerogel-derived carbon quantum dots modified BiOCl nanocomposites with augmented oxygen vacancies for enhanced photodegradation of antibiotics

Abstract

Composite carbon quantum dots (CQDs), characterize as zero-dimensional carbon nanomaterial, play a crucial role in accelerating the separation of photoelectron-hole pairs within photocatalysts. Moreover, they introduce abundant oxygen vacancies (OVs) and facilitate the formation of new defect levels. Therefore, in this study, CA/BiOCl-x was synthesized via the hydrothermal method using carbon aerogel (CA) as the precursor for CQDs endowed with visible light activity. Through the degradation of tetracycline hydrochloride (TCH), the results demonstrate that CA/BiOCl-6 % exhibits the most prominent photocatalytic efficiency, showcasing a degradation rate of TCH under visible light irradiation fourfold higher than that of pristine BiOCl. Furthermore, the degradation activity is significantly enhanced under full spectrum irradiation, achieving a degradation rate of ∼100 %. The observation indicated efficient integration of CQDs into BiOCl through C = O, introducing abundant OVs. Electrochemical analysis revealed that the enhancement of catalyst recombination significantly augmented both the lifetime of photogenerated carriers and the intensity of photocurrent. Active species quenching experiments indicated the superior role of superoxide radical (•O2−) in CA/BiOCl mediated TCH degradation. Liquid chromatography-mass spectrometry further confirmed the degradation pathways of contaminants. This study provides novel insights into the development of efficient photocatalysts for remediations of organic pollutants.