Triangle CeO2/g-C3N4 heterojunctions: Enhanced light-driven photocatalytic degradation of methylparaben

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Vol. 458; p. 115976
• Main Authors: Zografaki, Maria, Stefa, Sofia, Vamvasakis, Ioannis, Armatas, Gerasimos S., Chaidali, Andriani G., Lykakis, Ioannis N., Binas, Vassilios
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2025
• Subjects: CeO2/g-C3N4 heterojunctions; Methylparaben degradation; Photocatalytic activity; Stability; Visible light photocatalyst; Photocatalytic activity; Stability; Visible light photocatalyst; CeO2/g-C3N4 heterojunctions; Methylparaben degradation
• ISSN: 1010-6030
• DOI: 10.1016/j.jphotochem.2024.115976

[Display omitted] •Ultrathin triangle CeO2/g-C3N4 heterojunctions.•Type II heterojunctions 10%CeO2/CN showed significantly enhanced MP removal.•Synergistic effect of the effective combination of CeO2 triangles on CN.•Rate constant was 3.8 and 11.3 times higher than that of CN under solar/vis light.•1H NMR experiments we assume that after 420 min the MP was completely degraded. In this work, an efficient photocatalytic system for methylparaben (MP) removal, using solar (λ > 360 nm) and visible (λ > 420 nm) light-driven CeO2/g-C3N4 (CeO2/CN) heterojunctions is reported for the first time. The physicochemical properties of pure CeO2, CN, and CeO2/CN composites were investigated using characterization techniques, such as XRD, FESEM-EDS, TEM, UV–Vis, PL, XPS, and electrochemical spectroscopy. Among the catalysts with different mass ratios of CeO2, 10 %CeO2/CN showed the best photocatalytic performance. This is attributed to the enhanced charge carrier’s separation because of the proper band-edge alignment between CN and CeO2 components, and the strong visible light absorbance. The photocatalytic degradation of MP followed the first-order kinetics, and the 10 %CeO2/CN catalyst exhibited a 3.8- and 11.3-times higher reaction rate (k) constant than that of pure CN, investigated under solar and visible light illumination, respectively. Further, scavenger trapping experiments confirmed that hydroxyl radicals (OH.) and dissolved oxygen are the predominant active species in MP oxidation over 10 %CeO2/CN composite catalyst. 1H NMR and LCMS-HPLC results and observations showed complete degradation of MP (0.1 g/L) to CO2 and H2O after 7 h of solar irradiation, due to the absence of the representative peaks of MP and its organic degradation products (e.g. phenols, benzoates).