Precursor-Dependent Photocatalytic Activity of Carbon Dots

Abstract

This work systematically compares both structural features and photocatalytic performance of a series of graphitic and amorphous carbon dots (CDs) prepared in a bottom-up manner from fructose, glucose, and citric acid. We demonstrate that the carbon source and synthetic procedures diversely affect the structural and optical properties of the CDs, which in turn unpredictably influence their photo electron transfer ability. The latter was evaluated by studying the photo-reduction of methyl viologen. Overall, citric acid-CDs were found to provide the best photocatalytic performance followed by fructose- and glucose-CDs. However, while the graphitization of glucose- and citric acid-CDs favored the photo-reaction, a reverse structure–activity dependence was observed for fructose-CDs due to the formation of a large graphitic-like supramolecular assembly. This study highlights the complexity to design in advance photo-active bio-based carbon nanomaterials.

Graphene oxide and its derivatives as promising In-vitro bio-imaging platforms

“…are further affected by the size, chemical functional groups, oxidation degree and other related factors 22,23 . GO can perform as an efficient quencher through either charge transfer or resonance energy 24 .…”

“…Under basic conditions, however, the fluorescence intensity may be recovered due to the produced COOmoieties 20,21 . Besides, the fluorescence emission and intensity of GO are further affected by the size, chemical functional groups, oxidation degree and other related factors 22,23 . GO can perform as an efficient quencher through either charge transfer or resonance energy 24 .…”

Recent Developments in Synthesis and Photocatalytic Applications of Carbon Dots

“…However, the contradict results of amorphous CDs were found for fructose precursor. The reason for this inversion was possibly due to the formation of the supramolecular aggregates from large graphitic materials, which affects the PET efficiency [77]. Another work additionally disclosed that the hydrothermal syntheses yielded amorphous CDs from citric acid, which were either nondoped (a-CDs) or nitrogen-doped (a-N-CDs), whereas the pyrolytic treatment afforded graphitic CDs, either non-doped (g-CDs) or nitrogen-doped (g-N-CDs) [78].…”

Carbon Dots: An Emerging Smart Material for Analytical Applications

“…The photocatalytic performance of the graphitic and amorphous CDs, which were synthesized using fructose, glucose, and citric acid, was investigated. In this study, the type of carbon source and the synthesis route that ultimately determines the potential of the photoelectron transfer determined the CD’s structure and optical properties [ 82 ]. Pure carbonaceous CDs (without dopants) in graphitic form exhibited better photoactivity than the amorphous one, whereas, in the case of nitrogen-doped CDs, the amorphous CDs exhibited better photoredox-activity due to the presence of photo-active molecule.…”