Local Reactivity on Carbon Quantum Dots: The Influence of the Geometries and Chemical Doping for Chemical Sensor Applications

Abstract

Carbon-based compounds have been considered materials of great technological interest, mainly due to their high synthesis flexibility, low cost, and unique properties. In particular, graphene-based compounds, such as modified graphene, graphene nanoribbons, and carbon quantum dots (CQD) show improved performance for a variety of applications. CQDs are particularly interesting; such zero dimensional structures usually show strong fluorescence, good water solubility, chemical stability, ease of functionalization and other properties that depend on the CQDs' geometries, sizes, and terminal edges. To better understand the influence of these factors on the electronic and reactivity properties of the CQDs, here we evaluate five different geometries and 11 chemical modifications of this material in a DFT framework using low computational cost electronic descriptors. The results indicate that geometries, edges, and chemical modifications have different roles in the local reactivities of these compounds. For instance, geometric features govern the orbital-based chemical reactivities, while the substituents' nature governs the molecular electrostatic potentials. The evaluation of frontier energy level alignments point out CQDs as potential materials for Cl 2 and SO 2 detection, which is reinforced by simulations via fully atomistic reactive molecular dynamics (FARMD).

Meta-Analysis of Molecular Design Strategies for Non-Fullerene Acceptor Based Organic Solar Cell Materials

“…28 These side chains were also predicted to perform well in our previous study that used genetic algorithms to design unfused NFAs. 19 There are not many studies on the effect of substituting units in unfused NFAs. Some studies have compared fluorene and carbazole central units, with differences in optical and electronic properties due to different electron-donating strengths.…”

“…In this work, the largest NFA-based OSC dataset to date was developed, expanding on our previous dataset 19 , and consisting of 1975 NFA/donor pairs curated from 842 papers. This dataset contains 1082 unique NFAs and 432 unique donors.…”

Peanut shell carbon quantum dots modified with citric acid: amplifying visual detection of fluorescence sensitivity for Cu2+

“…For the past few years, carbon quantum dots have attracted great attention due to their unique properties, such as stable photoluminescence, 9 low toxicity, 10 good biocompatibility, 11 and high solubility. 12 Carbon quantum dots have been greatly used in various applications, such as chemical sensing, 13 bioimaging, 14 biosensing, 15 and photocatalysis. 16 Different preparation methods have used different chemicals as the source of carbon or the surface passivation reagent.…”