Fast sonochemically-assisted synthesis of pure and doped zinc sulfide quantum dots and their applicability in organic dye removal from aqueous media

Rajabi, Hamid Reza; Karimi, Fatemeh; Kazemdehdashti, Hossein; Kavoshi, Leila

doi:10.1016/j.jphotobiol.2018.02.016

Cited by 89 publications

(27 citation statements)

References 50 publications

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“…A brief comparison between the obtained degradation efficiency of NOFX in the presence of undoped and Mn doped ZnS QDs (Figure 15) indicates that the doping of Mn in the crystalline structure of ZnS, as an impurity, has a positive effect on the degradation efficiency through photocatalysis. The improvement found after doping compared to the undoped sample is 4.2%, which is close to the values found in literature 2-3% [21,23,63].…”

Section: Effect Of Mn 2+ Dopant Concentrationsupporting

confidence: 90%

“…Also, zinc sulfide (ZnS) QDs are not poisonous, hence, they are the most popular preference for photocatalytic and biomedical uses [21,22]. Recently, ZnS, have been extensively inspected as novel semiconductors, in the field of photocatalysis, sensing and imaging, given their important properties, like visible-light response, suitable band positions, higher chemical and thermal stability, non-toxic and economical production [23][24][25]. However, reduced activity in visible light and the combination of photogenerated electron and hole pairs obstructs the large scale utilizations of these photocatalysts [26].…”

Section: Introductionmentioning

confidence: 99%

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Assessing the Photocatalytic Degradation of Fluoroquinolone Norfloxacin by Mn:ZnS Quantum Dots: Kinetic Study, Degradation Pathway and Influencing Factors

Patel¹,

Singh²,

Carabineiro

2020

Nanomaterials

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Norfloxacin (NOFX), a broadly used fluoroquinolone antibiotic, has been a subject of great concern in the past few years due to its undesirable effect on human beings and aquatic ecosystems. In this study, novel Mn doped ZnS (Mn:ZnS) quantum dots (QDs) were prepared through a facile chemical precipitation method and used as photocatalysts for NOFX degradation. Prior to photodegradation experiments, morphological and optical parameters of the QDs were examined through transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray analysis, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, fluorescence spectroscopy, Brunauer–Emmett–Teller analysis, and differential thermal and thermogravimetric analyses. Mn:ZnS QDs exhibited excellent properties of photodegradation, not only under UV irradiation but also in sunlight, which induced NOFX to photodegrade. The utmost photodegradation efficiency was obtained under optimal conditions (25 mL of NOFX, 15 mg/L, pH 10, 60 min UV irradiation, 60 mgs QDs), adopting first order kinetics. In addition, hydroxyl radicals produced by the conduction band electrons were found to be the primary reason dominating the transformation of NOFX in basic conditions, while holes, oxygen atoms, as well as the doped metal (Mn) enhanced the degradation. The QDs showed excellent reusability and stability in four repeated cycles. Finally, four different pathways were predicted, derived from the identified intermediates, with piperazinyl ring transformation being the primary one. It is expected that the synthesized Mn:ZnS QDs could be utilized as efficient photocatalytic materials for energy conversion and ecological remediation.

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Section: Effect Of Mn 2+ Dopant Concentrationsupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Assessing the Photocatalytic Degradation of Fluoroquinolone Norfloxacin by Mn:ZnS Quantum Dots: Kinetic Study, Degradation Pathway and Influencing Factors

Patel¹,

Singh²,

Carabineiro

2020

Nanomaterials

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“…However, the high energy gap of QDs reduces the amount of photon being absorbed in the solar spectrum [12]. Therefore, Doped QDs have lately suggested as an important aspect for solar energy photocatalyst [73]. The presence of dopants perturbs the band structure by modifying the density of states within the band gap.…”

Section: Doping In Quantum Dots (Qds)mentioning

confidence: 99%

Band edge positions as a key parameter to a systematic design of heterogeneous photocatalyst

Abdullah

2019

Eur J Chem

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Although, plenty of photocatalytic approaches have been developed in the past few decades to overcome major drawbacks, such as; wide band gap and fast volume/surface recombination of the charge carriers, the researchers still need to carry out careful systematic studies before conducting experiments based on physicochemical properties of a system. Thus, in this review, a detailed discussion of the band edge positions controlling the migration and charge separation of the produced charged carriers and its impact onto the photocatalytic systems are provided. The knowledge of band edge positions is a crucial prerequisite to a rational design of an efficient photocatalytic system. The enhancement mechanism should match these criteria to be reliable in the field of heterogeneous photocatalysis science.

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“…[1][2][3] These properties make QDs very promising tools in photoelectronic devices, biomedical and pharmaceutical fields. 4 According to the literature, QDs could be used in targeted drug delivery, 5 multiplexed bioimaging, 6 diagnostic, 7 luminescent sensors 8,9 and nanophotocatalysts 10,11 applications after they coupled with different molecules. Despite the numerous benefits provided by QDs, people still have doubts about their potential harmful health effects, which are related to the heavy metals such as Cd, Pb, As, and Te in these materials.…”

Section: Introductionmentioning

confidence: 99%

<p>In vivo Comparison of the Biodistribution and Toxicity of InP/ZnS Quantum Dots with Different Surface Modifications</p>

Chen

et al. 2020

IJN

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Introduction: Indium phosphide (InP) quantum dots (QDs) have shown a broad application prospect in the fields of biophotonics and nanomedicine. However, the potential toxicity of InP QDs has not been systematically evaluated. In particular, the effects of different surface modifications on the biodistribution and toxicity of InP QDs are still unknown, which hinders their further developments. The present study aims to investigate the biodistribution and in vivo toxicity of InP/ZnS QDs. Methods: Three kinds of InP/ZnS QDs with different surface modifications, hQDs (QDs-OH), aQDs (QDs-NH 2), and cQDs (QDs-COOH) were intravenously injected into BALB/c mice at the dosage of 2.5 mg/kg BW or 25 mg/kg BW, respectively. Biodistribution of three QDs was determined through cryosection fluorescence microscopy and ICP-MS analysis. The subsequent effects of InP/ZnS QDs on histopathology, hematology and blood biochemistry were evaluated at 1, 3, 7, 14 and 28 days post-injection. Results: These types of InP/ZnS QDs were rapidly distributed in the major organs of mice, mainly in the liver and spleen, and lasted for 28 days. No abnormal behavior, weight change or organ index were observed during the whole observation period, except that 2 mice died on Day 1 after 25 mg/kg BW hQDs treatment. The results of H&E staining showed that no obvious histopathological abnormalities were observed in the main organs (including heart, liver, spleen, lung, kidney, and brain) of all mice injected with different surfacefunctionalized QDs. Low concentration exposure of three QDs hardly caused obvious toxicity, while high concentration exposure of the three QDs could cause some changes in hematological parameters or biochemical parameters related to liver function or cardiac function. More attention needs to be paid on cQDs as high-dose exposure of cQDs induced death, acute inflammatory reaction and slight changes in liver function in mice. Conclusion: The surface modification and exposure dose can influence the biological behavior and in vivo toxicity of QDs. The surface chemistry should be fully considered in the design of InP-based QDs for their biomedical applications.

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Fast sonochemically-assisted synthesis of pure and doped zinc sulfide quantum dots and their applicability in organic dye removal from aqueous media

Cited by 89 publications

References 50 publications

Assessing the Photocatalytic Degradation of Fluoroquinolone Norfloxacin by Mn:ZnS Quantum Dots: Kinetic Study, Degradation Pathway and Influencing Factors

Assessing the Photocatalytic Degradation of Fluoroquinolone Norfloxacin by Mn:ZnS Quantum Dots: Kinetic Study, Degradation Pathway and Influencing Factors

Band edge positions as a key parameter to a systematic design of heterogeneous photocatalyst

<p>In vivo Comparison of the Biodistribution and Toxicity of InP/ZnS Quantum Dots with Different Surface Modifications</p>

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