Life Cycle Assessment-Based Comparative Study between High-Yield and Standard Bottom-Up Procedures for the Fabrication of Carbon Dots

• Type: Article in International Scientific Journal
• Date: 2022-05-11

Authors

Luís Pinto da Silva (Author) FCUP; Sonia Fernandes (Author) FCUP; Joaquim C G E Esteves da Silva (Author) FCUP

Journal

Title: Materials

Vol. 429

Pages: 3446-3446

ISSN: 1996-1944

Publisher: MDPI

Indexing

ISI Web of Knowledge - 2 Citations

Scopus - 3 Citations

Associated Projects

ChemiTumorTher - Quimioluminescência Marinha como uma Terapia Anticancro de Amplo Espectro com uma Selectividade e Actividade Tumoral Melhorada

Other information

Authenticus ID: P-00W-H05

DOI: 10.3390/ma15103446

Abstract (EN): Carbon dots (CDs) are carbon-based nanomaterials with remarkable properties that can be produced from a wide variety of synthesis routes. Given that standard bottom-up procedures are typically associated with low synthesis yields, different authors have been trying to devise alternative high-yield fabrication strategies. However, there is a doubt if sustainability-wise, the latter should be really preferred to the former. Herein, we employed a Life Cycle Assessment (LCA) approach to compare and understand the environmental impacts of high-yield and standard bottom-up strategies, by applying different life cycle impact assessment (LCIA) methods. These routes were: (1) production of hydrochar, via the hydrothermal treatment of carbon precursors, and its alkaline peroxide treatment into high-yield CDs; (2) microwave treatment of carbon precursors doped with ethylenediamine; (3) and (6) thermal treatment of carbon precursor and urea; (4) hydrothermal treatment of carbon precursor and urea; (5) microwave treatment of carbon precursor and urea. For this LCA, four LCIA methods were used: ReCiPe, Greenhouse Gas Protocol, AWARE, and USEtox. Results identified CD-5 as the most sustainable synthesis in ReCiPe, Greenhouse Gas Protocol, and USEtox. On the other hand, in AWARE, the most sustainable synthesis was CD-1. It was possible to conclude that, in general, high-yield synthesis (CD-1) was not more sustainable than standard bottom-up synthesis, such as CD-5 and CD-6 (also with relatively high-yield). More importantly, high-yield synthesis (CD-1) did not generate much lower environmental impacts than standard approaches with low yields, which indicates that higher yields come with relevant environmental costs.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 22