Turning spent coffee grounds into sustainable precursors for the fabrication of carbon dots

Spent coffee grounds (SCGs) are known for containing many organic compounds of interest, including carbohydrates, lipids, phenolic compounds and proteins. Therefore, we investigated them as a potential source to obtain carbon dots (CDs) via a nanotechnology approach. Herein, a comparison was performed between CDs produced by SCGs and classic precursors (e.g., citric acid and urea). The SCG-based CDs were obtained via the one-pot and solvent-free carbonization of solid samples, generating nanosized particles (2.1–3.9 nm). These nanoparticles exhibited a blue fluorescence with moderate quantum yields (2.9–5.8%) and an excitation-dependent emission characteristic of carbon dots. SCG-based CDs showed potential as environmentally relevant fluorescent probes for Fe3+ in water. More importantly, life cycle assessment studies validated the production of CDs from SCG samples as a more environmentally sustainable route, as compared to those using classic reported precursors, when considering either a weight-or a function-based functional unit. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

Authors
Crista D.M.A.1 , El Mragui A. , Algarra M.2 , Esteves Da Silva J.C.G. , Luque R. 4, 5 , Da Silva L.P.
Journal
Publisher
MDPI AG
Number of issue
6
Language
English
Pages
1-17
Status
Published
Number
1209
Volume
10
Year
2020
Organizations
  • 1 Chemistry Research Unit (CIQUP), Faculty of Sciences of University of Porto, R. Campo Alegre 697, Porto, 4169-007, Portugal
  • 2 Department of Inorganic Chemistry, Faculty of Science, University of Málaga, Campus de Teatino s/n, Málaga, 29071, Spain
  • 3 LACOMEPHI, GreenUPorto, Department of Geosciences, Environment and Territorial Planning, Faculty of Sciences of University of Porto, R. Campo Alegre 697, Porto, 4169-007, Portugal
  • 4 Departamento de Química Orgánica, Universidad de Córdoba, Edif. Marie Curie, Ctra N-IVA Km 396, Córdoba, E-14014, Spain
  • 5 Center for Molecular Design and Synthesis of Innovative compounds for Medicine, Peoples Friendship University of Russia (RUDN University), 6 Miklukho Maklaya Street, Moscow, 117198, Russian Federation
Keywords
Carbon dots; Fluorescence; Life cycle assessment; Nanotechnology; Sensing; Spent coffee grounds
Date of creation
02.11.2020
Date of change
02.11.2020
Short link
https://repository.rudn.ru/en/records/article/record/64691/
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