Photobleaching and stabilization of carbon nanodots produced by solvothermal synthesis. Issue 1 (30th November 2015)

• Record Type: Journal Article
• Authors: Wang, Wenshuo; Damm, Cornelia; Walter, Johannes; Nacken, Thomas J.; Peukert, Wolfgang
• Is Part Of: Physical chemistry chemical physics. Volume 18:Issue 1(2016)
• Page Start: 466
• Page End: 475
• Publication Date: 2015-11-30
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c5cp04942c
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : In this work we performed a detailed investigation of the photostability of bottom-up produced carbon nanodots (CDs) prepared from citric acid and urea by solvothermal synthesis. Abstract : In this work we performed a detailed investigation of the photostability of bottom-up produced carbon nanodots (CDs) prepared from citric acid and urea by solvothermal synthesis. Analytical ultracentrifugation (AUC) reveals that the CDs have a hydrodynamic diameter of <1 nm and a very narrow size distribution. In the community it is widely assumed that CDs are photo-stable. In contrast, we found that CDs exposed to UV-irradiation exhibit noteworthy fluorescence degeneration compared to freshly prepared CDs or CDs stored in the dark, indicating that fluorescence bleaching is caused by a photochemical process. We found that fluorescence intensity decay due to exposure to UV-irradiation is accelerated in the presence of oxygen and identified the surface status of CDs as the decisive factor of fluorescence bleaching of CDs. Based on a discussion on the underlying mechanisms we show how to avoid photobleaching of CDs.