Electron spin dynamics in sucrose-derived luminescent carbon dot-silica nanocomposites

0566700 - FZÚ 2023 RIV GB eng J - Journal Article
Savchenko, Dariia - Vasin, A. - Rusavsky, A. - Nazarov, A. - Lančok, Ján
Electron spin dynamics in sucrose-derived luminescent carbon dot-silica nanocomposites.
Journal of Physics and Chemistry of Solids. Roč. 162, March (2022), č. článku 110536. ISSN 0022-3697. E-ISSN 1879-2553
R&D Projects: GA MŠMT(CZ) EF16_019/0000760
Grant - others:OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Institutional support: RVO:68378271
Keywords : carbon dots * electron spin resonance * exchange interaction * nanocomposites * spin dynamics
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 4, year: 2022
Method of publishing: Limited access
https://doi.org/10.1016/j.jpcs.2021.110536

A bottom-up approach to synthesize luminescent carbon dot-silica (CDs@SiO2) nanocomposites from the sucrose precursor was utilized. A single ESR line resulting from exchange interaction between localized and non-localized electrons was observed. The non-localized electrons were related to C-related radicals in the sp3-hybridized state, while the carbon dots (CDs) act as localized electrons. The observed narrowing of the exchange ESR line with temperature rise was explained by a combination of Anderson’s spin-exchange motional narrowing and a hopping wave function. The relation between CDs size and conductivity of the CDs@SiO2 nanocomposites was found. The metallic character of the CDs@SiO2 conductivity was explained by the quantum size effect occurred due to the reaggregation of the CDs. It was concluded that the previously observed shift of photoluminescence band and its further quenching with the increase of sucrose concentration in CDs@SiO2 is caused by the quantum size effect.

Permanent Link: https://hdl.handle.net/11104/0338006