Decoration of alumina hollow fibers with zinc oxide: improvement of the photocatalytic system for methylene blue degradation

Sousa, Thiago Sousa e; Ferreira, Eduardo de Paulo; Vieira, Patrícia Angélica; Reis, Miria Hespanhol Miranda

doi:10.1007/s11356-022-20397-6

Cited by 7 publications

(5 citation statements)

References 50 publications

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“…These electrons and holes have a high oxidation potential, allowing direct oxidation of MB. The formation of * OH − radicals and the reactions that occur during the photodegradation process are given in Equations ()–() 72,73 :

\begin{equation}{\mathrm{ZnO}} + {\mathrm{h}}v\; \to {\mathrm{ZnO\;}}\left( {{{\mathrm{e}}^ - } + {{\mathrm{h}}^ + }} \right),\end{equation}

\begin{equation}{{\mathrm{H}}_2}{\mathrm{O}} + {{\mathrm{h}}^ + }\; \to \;^*{{\mathrm OH}^ - } + {{\mathrm{H}}^ + },\end{equation}

\begin{equation}{{\mathrm{O}}_2} + {{\mathrm{e}}^ - }{\mathrm{\;}} \to \;^*{\mathrm{O}}_2^ - ,\end{equation}

\begin{equation} {\hspace*{0.28em}}^{\ast}{\mathrm{O}}_{2}^{-}\hspace*{0.28em}+{\mathrm{H}}^{+}\hspace*{0.28em}{\to \hspace*{0.28em}}^{\ast}\mathrm{HOO}, \end{equation}

\begin{equation} {2\hspace*{0.28em}}^{\ast}\mathrm{HOO}\to {\mathrm{H}}_{2}{\mathrm{O}}_{2}+{\mathrm{O}}_{2}, \end{equation}

…”

Section: Resultsmentioning

confidence: 99%

“…These electrons and holes have a high oxidation potential, allowing direct oxidation of MB. The formation of *OH − radicals and the reactions that occur during the photodegradation process are given in Equations ( 3)-( 9) 72,73 :…”

Section: Photocatalytic Properties Of Zno-coated Ceramics With Varyin...mentioning

confidence: 99%

“…(9) Azmina et al 20 grew ZnO nanoparticles on sand microparticles and used 30 mg of adsorbent to degrade 100 mL of MB with a 5 mg/L concentration at a 71.7% level. On the other hand, Sousa et al 73 impregnated Al 2 O 3 hollow fiber with ZnO and investigated the MB degradation under 150 W visible light. According to their conclusions, ∼95% of the MB degraded with a 5 mg/L using 1000 mg/L catalyst.…”

Section: Photocatalytic Properties Of Zno-coated Ceramics With Varyin...mentioning

confidence: 99%

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Photocatalytic properties of ZnO nanoparticle coating on porous ceramic substrates with varying porosities produced from fly ash and red mud

Özcan,

Birol,

Dülger Kutlu

et al. 2023

Int J Applied Ceramic Tech

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In order to improve filtering efficacy, nanoparticles are often deposited as photocatalytic degrading agents onto porous ceramics. This study aimed to deposit ZnO nanoparticles on ceramic substrates produced from fly ash and red mud with adjustable porosity and investigate their photocatalytic properties. To achieve this goal, at first porous ceramics were produced and sintered at various temperature/time intervals. It was observed that sintering at 800°C for 120 min provided a proper structure and porosity. In addition, MgO replacement with MgCO3 lowered the water absorption of the samples from 25.63% to 11.45%. The samples were then coated with ZnO nanoparticles using the sol–gel method and the ZnO structures obtained were micron‐sized plates. It was observed that increasing porosity increased the ZnO amount and accordingly the photocatalytic properties of the products. During the adsorption tests conducted in the dark, the coated ceramic samples were stained with MB with a maximum MB adsorption ratio of ∼14%. On the other hand, no visible MB stain was observed on the samples that were exposed to UV irradiation, and the MB removal after the UV irradiation was 93.6%; therefore, it was concluded that the dominant MB removal mechanism was photocatalytic.

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\begin{equation}{\mathrm{ZnO}} + {\mathrm{h}}v\; \to {\mathrm{ZnO\;}}\left( {{{\mathrm{e}}^ - } + {{\mathrm{h}}^ + }} \right),\end{equation}

\begin{equation}{{\mathrm{H}}_2}{\mathrm{O}} + {{\mathrm{h}}^ + }\; \to \;^*{{\mathrm OH}^ - } + {{\mathrm{H}}^ + },\end{equation}

\begin{equation}{{\mathrm{O}}_2} + {{\mathrm{e}}^ - }{\mathrm{\;}} \to \;^*{\mathrm{O}}_2^ - ,\end{equation}

\begin{equation} {\hspace*{0.28em}}^{\ast}{\mathrm{O}}_{2}^{-}\hspace*{0.28em}+{\mathrm{H}}^{+}\hspace*{0.28em}{\to \hspace*{0.28em}}^{\ast}\mathrm{HOO}, \end{equation}

\begin{equation} {2\hspace*{0.28em}}^{\ast}\mathrm{HOO}\to {\mathrm{H}}_{2}{\mathrm{O}}_{2}+{\mathrm{O}}_{2}, \end{equation}

…”

Section: Resultsmentioning

confidence: 99%

“…These electrons and holes have a high oxidation potential, allowing direct oxidation of MB. The formation of *OH − radicals and the reactions that occur during the photodegradation process are given in Equations ( 3)-( 9) 72,73 :…”

Section: Photocatalytic Properties Of Zno-coated Ceramics With Varyin...mentioning

confidence: 99%

Section: Photocatalytic Properties Of Zno-coated Ceramics With Varyin...mentioning

confidence: 99%

See 1 more Smart Citation

Photocatalytic properties of ZnO nanoparticle coating on porous ceramic substrates with varying porosities produced from fly ash and red mud

Özcan,

Birol,

Dülger Kutlu

et al. 2023

Int J Applied Ceramic Tech

View full text Add to dashboard Cite

show abstract

“…In our previous works, palladium (Silva et al 2020), graphite (Terra et al 2018) and graphene oxide (Ribeiro et al 2022) were successfully deposited on the outer surface of ceramic hollow bers and the composite membranes were used for gas permeations. Also, different oxide catalysts were deposited inside the microvoids of alumina hollow bers and the composite systems were evaluated for Cr(VI) (Costa et al 2019) and methylene blue (Sousa et al 2022) photodegradations. However, the evaluation of a proper assembling of catalysts in asymmetric hollow bers was not yet systematically studied.…”

Section: Introductionmentioning

confidence: 99%

Well-dispersed titanium dioxide and silver nanoparticles on external and internal surfaces of asymmetric alumina hollow fibers for enhanced chromium (VI) photoreductions

Costa

Ribeiro

Nascimento

et al. 2023

Environ Sci Pollut Res

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Silver (Ag)-decorated titanium dioxide (TiO 2 ) catalysts were produced under ultrasound irradiation at different loadings of Ag nanoparticles (from 5 to 50 wt%). Then, the catalysts were supported on internal and external surfaces of alumina hollow bers with asymmetric pore size distribution. The produced catalysts were considered for Cr(VI) photoreductions. The ultrasound-assisted process potentialized the distribution of Ag nanoparticles on the TiO 2 surface. The loading of Ag nanoparticles at concentrations greater than 5 wt% was necessary to improve the TiO 2 activity for Cr(VI) photoreduction. The loading of Ag nanoparticles at 30 wt% improved the Cr(VI) photoreduction of the single TiO 2 catalyst from 40.49 ± 0.98 to 55.00 ± 0.83% after 180 min of reaction. Suspended and supported Ag-decorated TiO 2 catalysts achieved total Cr(VI) photoreduction after 21 h of reaction. The adjusted reaction rate constant with the externally supported Ag-TiO 2 catalyst was 3.57x10 -3 ± 0.18 x10 -3 min -1 . Similar reaction rate constants were achieved with suspended and internally supported catalysts (approximately 2.70x10 -3 min -1 ). After 10 sequential reuses, all catalysts presented similar Cr(VI) photoreductions of approximately 66%.Nevertheless, the use of the externally supported catalyst is suggested for Cr(VI) photoreductions due to its superior catalyst activity at least in the rst reuse cycles. HighlightsProduction and decoration of Ag nanoparticles on TiO 2 by ultrasound irradiation Cr(VI) photoreduction is favored by the increase in Ag nanoparticle loading Supporting of Ag-decorated TiO2 catalysts on alumina hollow bers Externally supported catalysts presented superior reaction rate for Cr(VI) reduction

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Section: Introductionmentioning

confidence: 99%

Well-dispersed titanium dioxide and silver nanoparticles on external and internal surfaces of asymmetric alumina hollow fibers for enhanced chromium (VI) photoreductions

Costa

Ribeiro

Nascimento

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

Silver (Ag)-decorated titanium dioxide (TiO2) catalysts were produced under ultrasound irradiation at different loadings of Ag nanoparticles (from 5 to 50 wt%). Then, the catalysts were supported on internal and external surfaces of alumina hollow fibers with asymmetric pore size distribution. The produced catalysts were considered for Cr(VI) photoreductions. The ultrasound-assisted process potentialized the distribution of Ag nanoparticles on the TiO2 surface. The loading of Ag nanoparticles at concentrations greater than 5 wt% was necessary to improve the TiO2 activity for Cr(VI) photoreduction. The loading of Ag nanoparticles at 30 wt% improved the Cr(VI) photoreduction of the single TiO2 catalyst from 40.49 ± 0.98 to 55.00 ± 0.83% after 180 min of reaction. Suspended and supported Ag-decorated TiO2 catalysts achieved total Cr(VI) photoreduction after 21 h of reaction. The adjusted reaction rate constant with the externally supported Ag-TiO2 catalyst was 3.57x10-3 ± 0.18 x10-3 min-1. Similar reaction rate constants were achieved with suspended and internally supported catalysts (approximately 2.70x10-3 min-1). After 10 sequential reuses, all catalysts presented similar Cr(VI) photoreductions of approximately 66%. Nevertheless, the use of the externally supported catalyst is suggested for Cr(VI) photoreductions due to its superior catalyst activity at least in the first reuse cycles.

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Decoration of alumina hollow fibers with zinc oxide: improvement of the photocatalytic system for methylene blue degradation

Cited by 7 publications

References 50 publications

Photocatalytic properties of ZnO nanoparticle coating on porous ceramic substrates with varying porosities produced from fly ash and red mud

Photocatalytic properties of ZnO nanoparticle coating on porous ceramic substrates with varying porosities produced from fly ash and red mud

Well-dispersed titanium dioxide and silver nanoparticles on external and internal surfaces of asymmetric alumina hollow fibers for enhanced chromium (VI) photoreductions

Well-dispersed titanium dioxide and silver nanoparticles on external and internal surfaces of asymmetric alumina hollow fibers for enhanced chromium (VI) photoreductions

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