Turning Spent Coffee Grounds into Sustainable Precursors for the Fabrication of Carbon Dots

• Type: Article in International Scientific Journal
• Date: 2020

Authors

Crista, DMA (Author) Other; El Mragui, A (Author) Other; Algarra, M (Author) Other; Joaquim C G E Esteves da Silva (Author) FCUP; Luque, R (Author) Other; da Silva, LP (Author) FCUP

Journal

Title: Nanomaterials

Vol. 10

Pages: 1-17

ISSN: 2079-4991

Publisher: MDPI

Indexing

ISI Web of Knowledge - 28 Citations

Scopus - 31 Citations

Other information

Authenticus ID: P-00S-B31

DOI: 10.3390/nano10061209

Abstract (EN): 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 Fe(3+)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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 17