Synthesis, photocatalytic activity, and photogenerated hydroxyl radicals of monodisperse colloidal ZnO nanospheres

Yang, Chong; Li, Qingsong; Tang, Limei; Xin, Kun; Bai, Ailing; Yu, Yingmin

doi:10.1016/j.apsusc.2015.09.140

Cited by 64 publications

(21 citation statements)

References 75 publications

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“…This step causes release of electrons from this surface and penetrates them into the conduction band of ZnO, leaving behind positively charged IBP surface. This situation propagates the direct contact between organic pollutant and catalyst surface (Mahmoud & Fouad, ; Yang et al., ). At the next stage, the ZnO particles generate electron‐hole pairs which could migrate to the catalyst surface and produce

O_{2}^{\cdot -}

by reacting with surface‐absorbed oxygen.…”

Section: Resultsmentioning

confidence: 99%

Photocatalytic degradation of ibuprofen in water using TiO₂ and ZnO under artificial UV and solar irradiation

Tanveer

Guyer²,

Abbas

2019

Water Environment Research

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The degradation of anti‐inflammatory and antipyretic drug (Ibuprofen; IBP) has been described in this study by using photocatalytic‐based advanced oxidation processes. The catalysts (TiO2 and ZnO) were activated by irradiation of artificial UV lamp and solar rays for the generation of highly oxidizing species which resulted in the degradation of IBP to intermediates and finally to carbon dioxide and water. In solar reactor, quartz and borosilicate tubes were installed for absorption of required ultraviolet rays and curved chrome plates were used to reflect and concentrate rays on the tubes containing feed mixture. The liquid chromatography, Total organic carbon (TOC), and Chemical oxygen demand (COD) tests were employed to determine the degradation rates and demineralization of solution samples. At catalyst dosing of 1–1.5 g/L, TiO2‐based experiments showed high degradation rate under acidic conditions. Similarly, for ZnO catalyst, 1 g/L dozing rate was found to be effective under neutral conditions (pH = 7.0). UV lamp‐based photocatalysis had higher degradation rate as compared to that of solar reactor. Moreover, better absorption of solar rays by quartz tubes resulted in higher degradation than that in borosilicate tubes. For UV lamp photocatalysis, the TOC and COD reduction was higher. With improved catalyst doping and better solar reactor design, solar‐based IBP degradation could be more promising than UV‐based catalysis. Practitioner points TiO2 and ZnO were employed to generate oxidizing agents for comparative photocatalytic degradation. Degradation rate of Ibuprofen with TiO2 was much higher compared to ZnO. Quartz material was found more effective as radiation absorbing material than borosilicate glass for solar photo catalysis. Influence of catalyst loading (TiO2 and ZnO) and pH conditions on degradation rate and mineralization of IBP was examined. IBP is a carcinogenic and endocrine disrupting drug so its degradation in water can protect ecological and human life.

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O_{2}^{\cdot -}

by reacting with surface‐absorbed oxygen.…”

Section: Resultsmentioning

confidence: 99%

Photocatalytic degradation of ibuprofen in water using TiO₂ and ZnO under artificial UV and solar irradiation

Tanveer

Guyer²,

Abbas

2019

Water Environment Research

View full text Add to dashboard Cite

show abstract

“…According to this formula, as illustrated in figure b, the energies gap values of all these ZnO were counted to be 3.16(S4), 3.22(S3), 3.26(S1), 3.30ev(S2), respectively and are consistent with the values reported in previous literatures. In this result, band‐gap energy of these ZnO increase gradually, which might be due to the grain size estimated from XRD datas decrease gradually (quanta dimension effect) . the increase of band‐gap energy can improve the redox ability of these ZnO with hierarchical structure, but the stronger light source is needed at the same time .…”

Section: Resultsmentioning

confidence: 83%

“…Apparently, the strong absorption band of all of the ZnO is lesser than 390 nm, which is mainly due to their wide band gap. The band gap energies of as–prepared samples can be estimated from the following equation :

{((), ahv)}^{2} = A (hv - Eg)

…”

Section: Resultsmentioning

confidence: 99%

Template‐free synthesis of hierarchical zinc oxide with improved photocatalytic properties

Wang

Han

Song

et al. 2016

Crystal Research and Technology

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Novel hierarchical nano materials possess tremendous latent force in many applications. In this paper, hierarchical flower-like, spherical and bowl-like zinc oxide was successfully synthesized by altering solvent ratio (absolute ethanol and diethylene glycol) via a simple and templatefree solvothermal synthetic route. The solvent ratio also plays a vital role in deciding the structure, crystalline, band gap energy and specific surface area of the as-synthesized samples. The preparation mechanism of ZnO in mixed alcohols was discussed. The obtained samples were characterized by energy dispersive spectroscopy(EDS), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), N2 adsorption-desorption, UV-vis diffuse reflectance spectroscopy (DRS). Photocatalytic activity of the as-prepared ZnO nanocrystals was evaluated by the degradation of MB under UV irradiation. Among, the most effective photocatalyst was synthesized when the diethylene glycol was 10 ml.

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“…Samples have a H3 hysteresis loop belonging to type‐IV isotherms, it reveals that the macropores exist in catalysts; the consequence might be attributed to the aggregation of thin nanosheets, each pore size of the three samples reached to 270 nm through observing the corresponding figure ( Figure ). It can be speculate that S2 sample has the underlying excellent photocatalytic properties due to the larger specific surface area, providing more active site to quicken up reaction rate …”

Section: Resultsmentioning

confidence: 99%

“…The UV–vis diffuse reflectance spectra ( Figure ) exhibits that the absorption edges of samples are reach to 573(S1), 683(S2) and 588(S3) nm respectively, illuminating that the catalyst can respond to visible light. The formula below is used to calculate the band gap energies of as‐received sample:

α normalh ν = A {((), h ν - E_{g})}^{n / 2}

…”

Section: Resultsmentioning

confidence: 99%

Fabrication of BiOI Hierarchical Microspheres with Efficient Photocatalysis for Methylene Blue and Phenol Removal

Wang

Song

Hou

et al. 2017

Crystal Research and Technology

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BiOI hierarchical microspheres were synthesized by a solvothermal method. The different ratio of the amount of substance (Bi:I) drastically affects the feature that is embodied in multiaspect, such as crystallinity, morphological characteristics, component content, specific surface area and band gap width. These dissimilarities exert a great influence on photocatalytic performance. Ethylene glycol acts as soft template to guide the generation of the hierarchical microspheres. The presence of methanol has a positive effect on uniformity of reaction system in physical and chemical properties, because of its easy dispersibility and intersolubility. With interaction of mixed solvent, it leads to generate the uniform microspheres. The as‐received samples are characterized by X‐ray diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), energy dispersive spectroscopy(EDS), N2 adsorption‐desorption, UV–vis diffuse reflectance spectroscopy (DRS), X‐ray photoelectron spectroscopy (XPS), and fluorescence spectrophotometer. The formation of BiOI hierarchical microspheres were discussed with variational ratio of the amount of substance in mixed alcohol. To evaluate photocatalysis of as‐prepared BiOI, the methylene blue and phenol were exposed to visible light, which indicated degradation efficiency up to 98.09% just in 50 min and 94.14% within 6 h. The result shows that BiOI hierarchical microsphere is a promising photocatalyst in practical application.

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Synthesis, photocatalytic activity, and photogenerated hydroxyl radicals of monodisperse colloidal ZnO nanospheres

Cited by 64 publications

References 75 publications

Photocatalytic degradation of ibuprofen in water using TiO₂ and ZnO under artificial UV and solar irradiation

Photocatalytic degradation of ibuprofen in water using TiO₂ and ZnO under artificial UV and solar irradiation

Template‐free synthesis of hierarchical zinc oxide with improved photocatalytic properties

Fabrication of BiOI Hierarchical Microspheres with Efficient Photocatalysis for Methylene Blue and Phenol Removal

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Synthesis, photocatalytic activity, and photogenerated hydroxyl radicals of monodisperse colloidal ZnO nanospheres

Cited by 64 publications

References 75 publications

Photocatalytic degradation of ibuprofen in water using TiO2 and ZnO under artificial UV and solar irradiation

Photocatalytic degradation of ibuprofen in water using TiO2 and ZnO under artificial UV and solar irradiation

Template‐free synthesis of hierarchical zinc oxide with improved photocatalytic properties

Fabrication of BiOI Hierarchical Microspheres with Efficient Photocatalysis for Methylene Blue and Phenol Removal

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Product

Resources

About

Photocatalytic degradation of ibuprofen in water using TiO₂ and ZnO under artificial UV and solar irradiation

Photocatalytic degradation of ibuprofen in water using TiO₂ and ZnO under artificial UV and solar irradiation