Use of curcumin as a sensitizer with ZnO nanoparticles for the visible light photocatalytic degradation of methylene blue

• Published in: Reaction kinetics, mechanisms and catalysis Vol. 137; no. 5; pp. 2827 - 2845
• Main Authors: Baleh, Hinane, Bassaid, Salah, Dehbi, Abdelkader, Benaouda, Abderrahmen, Bouazza, Asmaa, Alsalme, Ali, Bonelli, Barbara, Messori, Massimo
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.10.2024
• Subjects: Catalysis; Chemistry; Chemistry and Materials Science; Industrial Chemistry/Chemical Engineering; Physical Chemistry; Zinc oxide; Curcumin; Photosensitizer; Photocatalysis; Methylene blue
• ISSN: 1878-5190; 1878-5204
• DOI: 10.1007/s11144-024-02669-z

This work aims to examine the application of ZnO/Curcumin nanocomposite materials, in which curcumin (natural dye) is used as a photosensitizer in the photocatalytic degradation of methylene blue (MB) under visible light irradiation. The ZnO/x% curcumin nanocomposite materials (with x = 3, 5, 7, 10 and 20) are prepared by the wet impregnation method. These nanocomposite materials are characterized using various techniques; including Fourier transform infrared spectroscopy, X-ray diffraction, ultraviolet–visible spectroscopy and scanning electron microscopy. Optimal MB degradation of ~ 99% was obtained with a concentration of 0.5 g L −1 of 5% curcumin/ZnO nanocomposite catalyst material, at natural pH and initial MB concentration of 10 mg L −1 for 90 min exposure to visible light irradiation. The kinetic indicates that the Langmuir–Hinshelwood (L–H) model is well adapted to the experimental data. Pseudo-first order kinetics were obtained with a rate constant (k) and half-life time ( t 1 / 2 ) of 0.0423 min −1 and 16 min. The significant improvement in the photocatalytic properties of ZnO under visible light irradiation induced by the addition of curcumin as a photosensitizer could be due to the increase in the concentration of reactive radical species in the solution, such as superoxide ( O 2 · - ) and hydroxyles ( OH · ).