Evaluation of the photocatalytic degradation mechanism of methylene blue using nascent and Ag + ions-modified TiO 2 .

Autor: Saqib NU; Department of Chemistry, University of Buner, Khyber Pakhtunkhwa, Pakistan. najm_saqib@yahoo.com., Shah I; Department of Chemistry, Abbottabad University of Science and Technology, Abbottabad, Pakistan., Adnan R; School of Chemical Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia. r_adnan@usm.my., Zaman F; Department of Physics, University of Buner, Khyber Pakhtunkhwa, Pakistan., Imam SS; Department of Pure and Industrial Chemistry, Bayero University, P.M.B 3011, Kano, Nigeria., Jan HA; Department of Botany, University of Buner, Khyber Pakhtunkhwa, Pakistan., Aamir A; Department of Chemistry, University of Buner, Khyber Pakhtunkhwa, Pakistan., Haleem MA; Department of Chemistry, University of Buner, Khyber Pakhtunkhwa, Pakistan.
Jazyk: angličtina
Zdroj: Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology [Photochem Photobiol Sci] 2024 Feb; Vol. 23 (2), pp. 245-256. Date of Electronic Publication: 2023 Dec 18.
DOI: 10.1007/s43630-023-00513-2
Abstrakt: In photocatalytic removal of organic pollutants, adsorption and degradation are two important processes that take place. Various instrumental techniques and trapping experiments have been used to identify the reactive species and the mechanism of photodegradation. The present work focuses on investigating the mechanism of photo-induced degradation from the comparative characterization of fresh and used samples, isotherm models, competitive adsorption, and desorption studies of pure and Ag + -modified TiO 2 NPs. The comparative characterizations of fresh and used NPs were carried out with FT-IR, EDX, and XRF analyses after methylene blue (MB) degradation. The Ag + doped TiO 2 used in this study was fabricated using simple impregnation technique. The prepared NPs were characterized using techniques including XPS, XRD, SEM/EDX, XRF, UV-DRS, and pH point-zero charge analyses (pH PZC ). The Ag + -modified TiO 2 NPs showed improved efficiency compared to pure TiO 2 NPs using normal compact fluorescent light (CFL). The Langmuir and Freundlich isotherm models were applied to test the adsorption behavior on the surface photocatalysts. The investigational data finest fitted to the Langmuir isotherms model compared to Freundlich model, suggesting the homogeneous monolayer adsorption followed by degradations. The competitive removal of MB in the presence of a photo-generated electrons trapper (Cd 2+ ) was enhanced almost 3-folds (115 mg/L) compared to the removal from a single MB solution (40 mg/L). The characterization of the used samples as well as adsorption in the dark and negligible desorption of used samples support the involvement of the proposed photo-induced degradation mechanism.
(© 2023. The Author(s), under exclusive licence to European Photochemistry Association, European Society for Photobiology.)
Databáze: MEDLINE
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