A novel ternary Z-scheme g-C3N4/CQDs/FeVO4 heterojunction for photodegradation of levofloxacin via peroxymonosulfate activation

Currently, it is still a significant challenge for photodegradation of the emerging pollutants using g-C3N4 (CN) due to their interior visible light responsibility and rapid recombination of e-/h+. Herein, a novel Z-scheme g-C3N4/CQDs/FeVO4 (CCF) photocatalyst was synthesized by initially preparing hollow tubular g-C3N4/CQDs (CC) and then anchoring FeVO4 on CC. The morphology, structural composition and photoelectrochemical performance of the CCF were investigated by comprehensive characterization such as FT-IR, XPS, XRD, SEM and photoelectrochemical performance tests. The CCF shows superior photodegradation capability toward LFX via activation of peroxymonosulfate (PMS), resulting in a photodegradation efficiency ∼ 97.3 % in the optimal conditions. Apart from the strengthened light responsibility, improved BET specific surface area and porous texture of CCF, the improved photodegradation properties can be ascribed to the formed Z-scheme heterojunction between CC and FeVO4, which can ameliorate the separation efficiency of e-/h+ and accelerate their transfer rate. The addition of CQDs can also serve as a channel for promoting the rapid transfer of photogenerated e-/h+. The photodegradation processes of LFX including generation of reactive oxygen species (ROS) and removal pathways were systematically explored by using radical capturing assays, electron spin resonance (ESR) tests and liquid chromatography-mass spectrometry (LC-MS) techniques. To sum up, this study provides an innovative method for regulating the photocatalytic activity of g-C3N4 via constructing Z-scheme heterostructures and incorporating CQD to degrade emerging contaminants.

Keywords

G-C3N4/CQDs/FeVO4 Z-scheme heterojunction Peroxymonosulfate Levofloxacin Photodegradation

URI

http://hdl.handle.net/10400.22/30451

Citation

Yunuo Li, Pengda Han, Dongzhe Zhang, Wenzhi Zhang, Dong-feng Chai, Lijian Meng, Liming Bai, Ming Zhao, Guohua Dong, A novel ternary Z-scheme g-C3N4/CQDs/FeVO4 heterojunction for photodegradation of levofloxacin via peroxymonosulfate activation, Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 727, Part 1, 2025, 138141, ISSN 0927-7757, https://doi.org/10.1016/j.colsurfa.2025.138141.