In Situ Stabilisation of Silver Nanoparticles at Chitosan-Functionalised Graphene Oxide for Reduction of 2,4-Dinitrophenol in Water
This investigation reports the in situ growth of silver nanoparticles onto covalently bonded graphene oxide-chitosan, which serve as supported nanocatalysts for the NaBH<sub>4</sub> reduction of 2,4-dinitrophenol in aqueous systems. Fumaryl chloride reacted with chitosan in an acidic env...
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| Autores principales: | , , , |
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| Formato: | article |
| Lenguaje: | EN |
| Publicado: |
MDPI AG
2021
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| Materias: | |
| Acceso en línea: | https://doaj.org/article/474440467b2c4e67961aa175aef100a1 |
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| Sumario: | This investigation reports the in situ growth of silver nanoparticles onto covalently bonded graphene oxide-chitosan, which serve as supported nanocatalysts for the NaBH<sub>4</sub> reduction of 2,4-dinitrophenol in aqueous systems. Fumaryl chloride reacted with chitosan in an acidic environment to yield a tailored polymeric material. The latter was, in turn, treated with the pre-synthesised graphene oxide sheets under acidic conditions to generate the GO-functionalised membrane (GO-FL-CS). The adsorption of Ag<sup>+</sup> from aqueous media by GO-FL-CS yielded a set of membranes that were decorated with silver nanoparticles (Ag NPs@GO-FL-CS) without any reducing agent. Various analytical tools were used to characterise these composites, including Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller surface area analysis, X-ray diffraction, scanning electron microscopy/energy-dispersive X-ray analysis, inductively coupled plasma-mass spectrometry, and transmission electron microscopy. The silver-loaded materials were further used for the remediation of 2,4-dinitrophenol from aqueous solutions under batch operation. The BET analysis revealed that the functionalisation of GO with chitosan and Ag NPs (average size 20–60 nm) resulted in a three-fold increased surface area. The optimised catalyst (Ag mass loading 16.95%) displayed remarkable activity with an apparent pseudo-first-order rate constant of 13.5 × 10<sup>−3</sup> min<sup>−1</sup>. The cyclic voltammetry experiment was conducted to determine the nitro-conversion pathway. The reusability/stability test showed no significant reduction efficiency of this metal-laden composite over six cycles. Findings from the study revealed that Ag NPs@GO-FL-CS could be employed as a low-cost and recyclable catalyst to convert toxic nitroaromatics in wastewater. |
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