Photocatalytic degradation of norfloxacin on different TiO<sub>2−X</sub> polymorphs under visible light in water

Yang, Hai; Mei, Liangyong; Wang, Pengcheng; Genereux, Joseph C.; Wang, Yinsheng; Yi, Bing; Au, Chak Tong; Dang, Limin; Feng, Pingyun

doi:10.1039/c7ra09022f

Cited by 30 publications

(8 citation statements)

References 67 publications

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“…Plausible intermediate formation was also spotted with the help of a HRMS study done with time-dependent norfloxacin degradation by 1% AT. The obtained results matched with the literature 39 and are summarized in Figure S12.…”

Section: Acs Applied Nano Materialssupporting

confidence: 85%

Degradation of Fluoroquinolone-Based Pollutants and Bacterial Inactivation by Visible-Light-Active Aluminum-Doped TiO₂ Nanoflakes

Kaushik

Samal

Halder

2019

ACS Appl. Nano Mater.

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The development of a visible-light-active photocatalyst for the removal of organic contaminants from water is of primary importance. In this work, we have developed a one-pot synthesis method for visible-light-active aluminum-doped titania (TiO2) with highly efficient sorption degradation of the fluoroquinolone-based pharmaceutical pollutant norfloxacin in aqueous solution. Here, we reduced the effective band gap of TiO2 by in situ doping of aluminum (1 mol %), which significantly improves the porosity, resulting in a high sorption capacity (209 mg/g) toward norfloxacin. The doping of aluminum in TiO2 makes it photocatalytically active in visible light and overcomes the shortcomings of undoped TiO2 in favor of the photodegradation process. 1% aluminum-doped TiO2 (AT) nanoflakes achieves 93% norfloxacin removal (of 2 × 10–4 M) in 2 h with almost 5 times higher rate constants (0.0143 min–1) compared to undoped TiO2 nanoflakes under visible light. Additionally, a high bacterial disinfection activity of doped samples compared to undoped TiO2 in visible light (nearly 80%) as well as in the dark (nearly 20%) was also observed toward both Staphylococcus aureus and Escherichia coli bacteria. The end product of the degradation process was analyzed using mass spectroscopy to determine the mechanistic pathways of the degradation process and the fate of the pollutants. The reusability of the prepared samples was tested and found to be active even after several cycles.

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Section: Acs Applied Nano Materialssupporting

confidence: 85%

Degradation of Fluoroquinolone-Based Pollutants and Bacterial Inactivation by Visible-Light-Active Aluminum-Doped TiO₂ Nanoflakes

Kaushik

Samal

Halder

2019

ACS Appl. Nano Mater.

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“…To achieve more vision into the probable mechanism of the photo‐decomposition of dyes, we made some extra researches. It is assumed that the reactive oxygen‐comprising radicals (O 2 •− and • OH) are created in the photocatalytic process . For • OH, we utilized a PL spectroscopic technique based on a terephthalic acid (TPA) reaction, which is repeatedly exploited in photocatalytic systems .…”

Section: Resultsmentioning

confidence: 99%

Excitons with Reverse Rectifying Characteristics for Superior Solar Photocatalysis

Samadi‐Maybodi

Shariati

2018

ChemistrySelect

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This study demonstrates an inverted energy‐gradient hybrid nanoparticle architecture that supports the formation of 2D excitons in the nanoshell domain. The developed geometry places a wide‐gap semiconductor quantum dot (ZnS, Eg= 3.68 eV) at the core of the nanocomposite particle in order to funnel the photoinduced energy into the low‐gap (CdS, Eg= 2.42 eV) shell layer. This inverted band regime helps to extract the photogenerated excitons into the shell and hence increases the exciton transport quantum efficiency, hereby leading to the superior photocatalytic efficiency for photoredox reactions over the nanohybrid. To demonstrate bandgap engineering and photoinduced charge carrier delocalization, we employed steady‐state and time‐resolved emission and absorption techniques in the presence and absence of an electron quencher (4‐nitrophenol) and hole quencher (4‐methoxyphenol). The significant suppression of band‐edge emissions and the decrement of the fluorescence lifetimes demonstrated the key role of nanoshell on the transfer of photogenerated charge carriers from core to the surface of the photocatalyst. Detailed investigations of the photocatalytic activity of ZnS@CdS and kinetic study of the reactions were also carried out under solar radiation. The contribution of O2•− and •OH to photocatalytic reactions revealed respectively via luminol chemiluminescence and terephthalic acid photoluminescence techniques.

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“…Yang et al prepared a series of anatase, rutile and brookite structures of TiO 2 as photocatalysts enabling complete degradation of 100 µM L −1 NOFX in 240 min with a dose of 0.1 gm TiO 2 [86]. According to Shankaraiah et al, about 90% of NOFX (150 mg/L) was accomplished under UV light after 180 min irradiation with 0.3 g TiO 2 .…”

Section: Identification Of Transformation Productsmentioning

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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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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Photocatalytic degradation of norfloxacin on different TiO_2−X polymorphs under visible light in water

Abstract: Reduced TiO2 (TiO2−X) materials with different crystallographic structures were prepared and characterized.

Cited by 30 publications

References 67 publications

Degradation of Fluoroquinolone-Based Pollutants and Bacterial Inactivation by Visible-Light-Active Aluminum-Doped TiO₂ Nanoflakes

Degradation of Fluoroquinolone-Based Pollutants and Bacterial Inactivation by Visible-Light-Active Aluminum-Doped TiO₂ Nanoflakes

Excitons with Reverse Rectifying Characteristics for Superior Solar Photocatalysis

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

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Photocatalytic degradation of norfloxacin on different TiO2−X polymorphs under visible light in water

Abstract: Reduced TiO2 (TiO2−X) materials with different crystallographic structures were prepared and characterized.

Cited by 30 publications

References 67 publications

Degradation of Fluoroquinolone-Based Pollutants and Bacterial Inactivation by Visible-Light-Active Aluminum-Doped TiO2 Nanoflakes

Degradation of Fluoroquinolone-Based Pollutants and Bacterial Inactivation by Visible-Light-Active Aluminum-Doped TiO2 Nanoflakes

Excitons with Reverse Rectifying Characteristics for Superior Solar Photocatalysis

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

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Photocatalytic degradation of norfloxacin on different TiO_2−X polymorphs under visible light in water

Degradation of Fluoroquinolone-Based Pollutants and Bacterial Inactivation by Visible-Light-Active Aluminum-Doped TiO₂ Nanoflakes

Degradation of Fluoroquinolone-Based Pollutants and Bacterial Inactivation by Visible-Light-Active Aluminum-Doped TiO₂ Nanoflakes