Confinement of Sustainable Carbon Dots Results in Long Afterglow Emitters and Photocatalyst for Radical Photopolymerization.
Angew Chem Int Ed Engl
; 63(39): e202402915, 2024 Sep 23.
Article
in En
| MEDLINE
| ID: mdl-38569128
ABSTRACT
Sustainable carbon dots based on cellulose, particularly carboxymethyl cellulose carbon dots (CMCCDs), were confined in an inorganic network resulting in CMCCDs@SiO2. This resulted in a material exhibiting long afterglow covering a time frame of several seconds also under air. Temperature-dependent emission spectra gave information on thermally activated delayed fluorescence (TADF) and room temperature phosphorescence (RTP) while photocurrent experiments provided a deeper understanding of charge availability in the dark period, and therefore, its availability on the photocatalyst surface. The photo-ATRP initiator, ethyl α-bromophenylacetate (EBPA), quenched the emission from the millisecond to the nanosecond time frame indicating participation of the triplet state in photoinduced electron transfer (PET). Both free radical and controlled radical polymerization based on photo-ATRP protocol worked successfully. Metal-free photo-ATRP resulted in chain extendable macroinitiators based on a reductive mechanism with either MMA or in combination with styrene. Addition of 9â
ppm Cu2+ resulted in Mw/Mn of 1.4 while an increase to 72â
ppm improved uniformity of the polymers; that is Mw/Mn=1.03. Complementary experiments with kerria laca carbon dots confined materials, namely KCDs@SiO2, provided similar results. Deposition of Cu2+ (9â
ppm) on the photocatalyst surface explains better uniformity of the polymers formed in the ATRP protocol.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Angew Chem Int Ed Engl
/
Angew. Chem. (Int. ed., Internet)
/
Angewandte Chemie (International ed. Internet)
Year:
2024
Document type:
Article
Affiliation country:
China
Country of publication:
Alemania