Mild bottom-up synthesis of carbon dots with temperature-dependent fluorescence

• Published in: Journal of luminescence 2021-10, Vol.238, p.118311, Article 118311
• Main Authors: Ye, Hong-Gang, Lu, Xuan, Cheng, Rui, Guo, Jiazhuang, Li, He, Wang, Cai-Feng, Chen, Su
• Format: Article
• Language: English
• Subjects: Bottom-up; Carbon dots; Mild synthesis; Photoluminescence; Temperature sensing
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2021.118311

Bottom-up methods allowing the preparation of carbon dots (CDs) with favorable attributes are highly desirable. Herein, we report the mild bottom-up synthesis of CDs towards temperature sensing. Five kinds of CDs with blue or green fluorescence were synthesized in water or tetrahydrofuran (THF) under moderate conditions (normal pressure, 50~95 °C), with use of carbonyl compounds as carbon sources, such as acetylacetone (AA), cyclohexanone (CH), 2-hydroxy-2-methylpropiophenone (HM), glutaric dialdehyde (GD), and salicylaldehyde (SA). Typically, with use of acetylacetone (AA) as carbon sources, CDs were synthesized at 95 °C in water in the presence of zinc chloride and 1, 2-dichloroethane. The synthesis, characterizations, and optical properties of AA-derived CDs were thoroughly investigated. The resultant CDs exhibit green photoluminescence (PL) at 520 nm with absolute PL quantum yield (QY) of 21%. Moreover, the PL intensity proportionally depends on temperature in the range 150–360 K, which makes AA-derived CDs potentially useful for temperature sensing. •A mild bottom-up method is developed to synthesize 5 kinds of carbon dots (CDs).•CDs are prepared from carbonyl compounds under normal pressure and 50~95 °C.•CDs show blue/green fluorescence with maximum absolute quantum yield of 21%.•Acetylacetone-derived CDs show fluorescence response to temperature (150–360 K).•CDs might be applied as sensors for temperature detection.