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The remediation of polluted water remains a critical environmental challenge due to the increasing anthropogenic activity. Advanced materials offer promising solutions for wastewater treatment by enabling contaminant adsorption and catalytic degradation [1]. Among these, nanostructured carbon materials, such as 3D porous graphene, exhibit high potential due to their high surface area, tunable porosity, and modifiable surface chemistry [2].
In this study, we introduce a novel, scalable, and eco-friendly method for synthesizing 3D porous graphene decorated by ZnO nanoparticles to address water pollution. Using the Laser-assisted Explosive Synthesis and Transfer (LEST) technique, porous graphene-like films were deposited onto metallic Zn foil substrates [3]. Upon immersion in aqueous solutions, the graphene films underwent in-situ decoration with ZnO microflowers, a process that occurs spontaneously under ambient conditions.
The resulting graphene/ZnO hybrid material exhibits a dual function for pollutant removal: (i) high adsorption efficiency due to the π-π interactions of sp² carbon with aromatic molecules and (ii) effective photocatalytic degradation under UV light, facilitated by the ZnO microstructures. Photocatalytic experiments using methylene blue (MB), a model cationic dye pollutant, demonstrate that the material achieves significant pollutant removal through combined adsorption and photocatalysis. The photocatalytic performance remains stable over multiple cycles, demonstrating the material’s reusability. Specifically, after a few photocatalytic cycles, the degradation rate remained approximately 80% after 25 hours, which is higher than the rate achieved using a film of ZnO nanoparticles as a photocatalyst without the 3D porous graphene substrate.
The observed pollutant degradation was correlated with the properties of the graphene/ZnO nanohybrids using various characterization techniques. The porous network observed through scanning electron microscopy (SEM) is characteristic of graphene-like structures synthesized via laser irradiation. This network is attributed to the rapid release of gases formed during the thermal decomposition of the carbonaceous precursor, induced by the absorption of laser pulses [4]. Raman and photoluminescence spectroscopies, along with X-ray photoelectron spectroscopy, revealed the time-dependent evolution of ZnO nanoparticles upon immersing the Zn-supported LEST-graphene films in water.
The LEST-based synthesis method offers significant advantages, including low energy consumption and compatibility with various substrates, making it a sustainable approach for producing advanced 3D porous materials. This study highlights the potential of 3D porous graphene/ZnO hybrids as multifunctional materials for wastewater treatment and lays the groundwork for further exploration of in-situ decoration strategies for environmental applications.
| References | [1] M. Lewoyehu, Comprehensive review on synthesis and application of activated carbon from agricultural residues for the remediation of venomous pollutants in wastewater, J. Anal. Appl. Pyrolysis 159 (2021) 105279. https://doi.org/10.1016/j.jaap.2021.105279. [2] K. Gu, E.J. Kim, S.K. Sharma, P.R. Sharma, S. Bliznakov, B.S. Hsiao, M.H. Rafailovich, Mesoporous carbon aerogel with tunable porosity as the catalyst support for enhanced proton-exchange membrane fuel cell performance, Mater. Today Energy 19 (2021) 100560. https://doi.org/10.1016/j.mtener.2020.100560. [3] K. Bhorkar, N. Samartzis, M. Athanasiou, L. Sygellou, N. Boukos, V. Dracopoulos, T. Ioannides, S.N. Yannopoulos, Laser-assisted explosive synthesis and transfer of turbostratic graphene-related materials for energy conversion applications, Npj 2D Mater. Appl. 6 (2022) 56. https://doi.org/10.1038/s41699-022-00331-7. [4] N. Samartzis, M. Athanasiou, V. Dracopoulos, S.N. Yannopoulos, T. Ioannides, Laser-assisted transformation of a phenol-based resin to high quality graphene-like powder for supercapacitor applications, Chem. Eng. J. 430 (2022) 133179. https://doi.org/10.1016/j.cej.2021.133179. |
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| Country | Greece |
| Water & Porous Media Focused Abstracts | This abstract is related to Water |
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