Reduced graphene oxide foams modified with caffeic acid for water decontamination: Capture and safe storage of Hg<sup>2+</sup>
Graphene-based materials are attractive adsorbents for water decontamination. In this work, we have produced eco-friendly reduced graphene oxide (rGO)-based sorbents by the hydrothermal reduction of graphene oxide (GO) in presence of caffeic acid (CA) and further modification with chitosan (CA_CS)....
| Autores: | , , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2024 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/390339 |
| Acesso em linha: | http://hdl.handle.net/10261/390339 https://api.elsevier.com/content/abstract/scopus_id/85204344018 |
| Access Level: | acceso abierto |
| Palavra-chave: | Caffeic acid Chitosan Mercury adsorption Reduced graphene oxide Porous foam |
| Resumo: | Graphene-based materials are attractive adsorbents for water decontamination. In this work, we have produced eco-friendly reduced graphene oxide (rGO)-based sorbents by the hydrothermal reduction of graphene oxide (GO) in presence of caffeic acid (CA) and further modification with chitosan (CA_CS). Scanning electron microscopy observations show porous macrostructures that turn more compact after CA or CA_CS modification. The specific surface area achieves a maximum value of 293 m2 g−1 for the pristine rGO foam. The macropores are mainly distributed in a range between 1–170 µm. The Hg2+ removal efficiency of the rGO-based foams was investigated across several different parameters. The foam modified with caffeic acid exhibited the most promising performance, demonstrating the highest removal efficiency at pH 4–6, with a maximum sorption capacity of 2.79 mg/g as determined by the Sips equation. Kinetic analysis indicates that intraparticle diffusion and the sorption itself are the rate-limiting steps. The notable sorption efficiency, the low desorption rate, and the applicability in real complex water matrices, including tap water, position rGO_CA as a viable material for efficiently capturing Hg(II) from large volumes of water and securely storing it in a small solid volume. |
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