Ag@ZnO/MWCNT ternary nanocomposite as an active and stable catalyst for the 4-nitrophenol reduction in water

García-Valdivieso, Guadalupe; Arenas-Sánchez, Eduardo; Horta-Fraijo, Patricia; Simakov, Andrey; Navarro‐Contreras, H.; Acosta, Brenda

doi:10.1088/1361-6528/abf96b

Cited by 8 publications

(6 citation statements)

References 79 publications

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“…Thus, for the Ag/ZA4‐MW catalyst, the reactivity tendency may also be associated with the steric effects. It is possible to propose that the presence of small metallic species finely dispersed into the zeolite structure can influence the reagents‐catalyst interaction [10,41] . So, the type and size of Ag species specified by the synthesis conditions must be analysed and correlated with the reaction rate.…”

Section: Resultsmentioning

confidence: 99%

Catalytic Transformation of Positional Nitrophenol Isomers on Highly Active Ag/Linde‐Type A4 Zeolite: A Comparative Analysis

et al. 2023

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The catalytic transformation of ortho-(o-NP), meta-(m-NP) and para-nitrophenols (p-NP) by Ag nanoparticles (Ag-NPs) stabilised on zeolite A4 (ZA4) is presented for the first time. The catalysts are prepared by microwave-assisted synthesis (Ag/ZA4-MW) or ion exchange (Ag/ZA4-IE). The results indicate that the nitrophenol reduction rate depends on the molecule structure and the presence of low-coordinated metallic Ag-NPs (~2 nm and sub nanometric species). Meanwhile, the reactivity tendency depends on the synthesis methodology (m-NP > p-NP > o-NP and o-NP > m-NP > p-NPfor Ag/ZA4-MW and Ag/ZA4-IE, respectively). The turnover frequency (TOF) values estimated for nitrophenols reduction are superior for Ag/ZA4-MW catalyst by several orders of magnitude compared with those obtained for Ag/ZA4-IE catalyst. In addition, the catalyst exhibits remarkable catalytic stability for the reduction of p-NP even after the fifth consecutive catalytic run. The presently prepared catalysts are characterised by superior catalytic activity for the reduction of nitroaromatic compounds than similar Ag-based materials reported in the literature.

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Section: Resultsmentioning

confidence: 99%

Catalytic Transformation of Positional Nitrophenol Isomers on Highly Active Ag/Linde‐Type A4 Zeolite: A Comparative Analysis

et al. 2023

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“…For a quantitative comparison, the activity parameter k' = k app /M was introduced, and defined as the ratio of the rate constant (k app ) to the Au loading (μmol) in the catalytic reaction mixture (M). The turnover frequencies (TOFs) values were estimated from the values of activity parameter by using the equation: [67,68] TOF ¼ k…”

Section: Resultsmentioning

confidence: 99%

“Click” Chemistry Assisted Synthesis of Magnetite‐CNT Nanohybrid Supported Gold Nanoparticles for Enhanced Catalytic Reduction of 4‐Nitrophenol

Mondal,

Samanta,

Salam Shaik

et al. 2023

ChemistrySelect

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The magnetite (Fe3O4) nanoparticles were strategically tethered over carbon nanotube (CNT) templates by using UV light‐induced thiol‐yne “click” chemistry approach which was followed by immobilization of chitosan stabilized gold nanoparticles (Au NPs) onto this surface through electrostatic interactions. Their application as a magnetically recyclable catalyst was explored through the study of the model catalytic reaction of reduction of 4‐nitrophenol (4‐NP) in the presence of an excess of NaBH4. Kinetic studies on the reduction of 4‐nitrophenol revealed Au/Fe3O4−CNT ternary nanohybrids to serve as better catalytic systems compared to Au NPs. The catalytic reduction of 4‐NP was found to occur through the formation of active gold hydride (Au−H) species. The formation of Au−H species was facilitated by Au−Fe3O4 interaction through the transfer of hydride ions via dissociation of the B−H bond of the adsorbed borohydride ions [BH4]− and the heterolytic dissociation of molecular hydrogen (H2), produced on hydrolysis of NaBH4 on the surface of Au/Fe3O4. Moreover, the π–π interactions between the nitroaromatic ring of 4‐NP and the CNT surface are believed to facilitate their proximity. Further, on visible light irradiation, dissociation of H2 on the gold surfaces was enhanced by the localized surface plasmon resonance (LSPR)‐induced hot electrons.

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“…Especially, bimetallic NPs composed of MWCNT are widely used for removing pollutants from aquatic mediums. [ 13–16 ] This shows that the bimetallic NPs contaminate the aquatic environment. Therefore, it is necessary to reveal the toxic effects of this newly synthesized NP in aquatic environments.…”

Section: Introductionmentioning

confidence: 98%

“…Bimetallic NPs gain very advanced and new properties as a result of the use of bimetallics. [13,14] Due to these important properties, bimetallic NPs are widely used in technological fields. Especially, bimetallic NPs composed of MWCNT are widely used for removing pollutants from aquatic mediums.…”

Section: Introductionmentioning

confidence: 99%

May PdCu@f‐MWCNT NPs be an ecotoxicologic risk?

Alak

Yeltekin

Köktürk

et al. 2023

Applied Organom Chemis

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The mechanisms of various metal nanoparticles (NPs) are still a matter of debate in aquatic toxicology. In order to close this gap, the number of studies on this subject is increasing. The aims of this study are to explore the interactions of PdCu@f-MWCNT NPs with zebrafish and get to know if it has an ecotoxicological risk. In this study, we synthesized, characterized PdCu@f-MWCNT NPs, and investigated its ecotoxicological effects. The chemical and morphological structures of PdCu@f-MWCNT nanomaterials were elucidated with advanced analysis techniques such as scanning electron microscope (SEM), X-ray spectrophotometer (EDX), transmission electron microscope (TEM), and X-ray diffraction (XRD) analyses. The ecotoxicological risks were investigated by conducting biochemical analyses and malformation defects in zebrafish. The results were obtained using multiple marker applications including oxidative stress parameters, proinflammatory cytokine expressions, DNA damage, and apoptosis markers. The obtained findings showed embryonic development, survival rate, and incidence of malformation increasing in parallel with the dose increase in zebrafish exposed to PdCu@f-MWCNT NPs at 10-1000 μg/L levels. Despite the observed decreases in antioxidant enzyme activities, GSH level, AChE activity, and NRF-2 level, inductions in malondialdehyde (MDA) level, IL-6, TNF-α, NF-kB, DNA damage, and apoptosis levels were observed with increasing dose. Considering these findings, it has been determined that there are toxic effects in zebrafish at all levels above the concentration that we examine as a safe dose (10 μg/L). The effects of all studied concentrations of this NP above the safe dosage, especially on oxidative stress, malformation, and immune system, were found to be quite significant. The more widespread use of nanotechnology in the future will mean more contact of aquatic organisms with NPs. As a result, it is clearly seen that these organisms, which form the important link of the food chain, and the aquatic environment are living at risk conditions.

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Ag@ZnO/MWCNT ternary nanocomposite as an active and stable catalyst for the 4-nitrophenol reduction in water

Cited by 8 publications

References 79 publications

Catalytic Transformation of Positional Nitrophenol Isomers on Highly Active Ag/Linde‐Type A4 Zeolite: A Comparative Analysis

Catalytic Transformation of Positional Nitrophenol Isomers on Highly Active Ag/Linde‐Type A4 Zeolite: A Comparative Analysis

“Click” Chemistry Assisted Synthesis of Magnetite‐CNT Nanohybrid Supported Gold Nanoparticles for Enhanced Catalytic Reduction of 4‐Nitrophenol

May PdCu@f‐MWCNT NPs be an ecotoxicologic risk?

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