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This study reports the synthesis, structural characterization, adsorption studies, nanoscale interaction, and photocatalytic application of pure and Fe-doped ZnS quantum dots for the degradation of the antibiotic cefalexin in aqueous solution. Nanoparticles were synthesized via the microwave-assisted method, and Fe doping was introduced at a 1% molar ratio. HRTEM images confirmed quasi-spherical morphology and high crystallinity, with particle sizes averaging 2.4 nm (pure) and 3.5 nm (doped). XRD analysis showed a consistent cubic ZnS structure. UV-vis spectra showed strong absorption at 316 nm for both samples, and PL measurements revealed emission quenching upon Fe doping. Photocatalytic tests under UV light demonstrated significantly higher degradation rates of 10 ppm cefalexin with Fe-doped ZnS, reaching near-complete removal within 90 min. Adsorption experiments revealed higher affinity and adsorption capacity of Fe-doped ZnS toward cefalexin compared to pure ZnS, as demonstrated by the Freundlich isotherm analyses, contributing significantly to enhanced photocatalytic degradation performance. High-resolution QTOF LC-MS analysis confirmed the breakdown of the β-lactam and thiazolidine rings of cefalexin and the formation of low-mass degradation products, including fragments at m/z 122.0371, 116.0937, and 318.2241. These findings provide strong evidence for the structural destruction of the antibiotic and validate the enhanced photocatalytic performance of Fe-doped ZnS.
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Fast One-Step Microwave-Assisted Synthesis of Iron-Doped ZnS for Photocatalytic Applications
Semiconductor Zn-based nanomaterials have emerged as promising agents for the photocatalytic degradation of organic pollutants in wastewater treatment. However, achieving efficient synthesis protocols capable of rapidly producing small structures directly in aqueous environments remains challenging. Microwave-assisted synthesis presents a viable solution by enabling one-step particle generation swiftly and directly in water through increased pressure, thereby easily elevating the boiling point. This study investigates the microwave-assisted one-step synthesis of pure and iron-doped ZnS nanoparticles and assesses their efficacy in photodegrading Quinoline Yellow (QY) in aqueous suspensions. The results demonstrate a significant degradation of QY in the presence of 1% iron-doped ZnS nanoparticles, achieving approximately 66.3% degradation with 500 ppm of doped nanoparticles after 270 min. These findings highlight the considerable potential of 1% iron-doped ZnS nanoparticles as effective nanocatalysts.
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- Award ID(s):
- 2313252
- PAR ID:
- 10530816
- Publisher / Repository:
- MDPI
- Date Published:
- Journal Name:
- Crystals
- Volume:
- 14
- Issue:
- 8
- ISSN:
- 2073-4352
- Page Range / eLocation ID:
- 699
- Subject(s) / Keyword(s):
- Fe-doped ZnS microwave-assisted synthesis photodegradation Quinoline Yellow dye.
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/cryst14080699
