Carbon Dots as Nano-Organocatalysts for Synthetic Applications

Abstract

Over the last decades, organic chemistry has taken a resolute step towards green catalytic synthesis. This tries to ensure efficient and sustainable base chemical production, while also safeguarding human health and environment. To this end, the development of novel, non-toxic and effective catalytic systems, capable of driving value-added chemical transformations in environmentally benign solvents (e. g. water) is highly desirable. Moreover, these new catalysts need to be metal-free, easy to prepare and potentially recyclable. Carbon dots, that are relatively new carbon-based nanoparticles, fulfil all these requirements owing to their outstanding physico-chemical features, thus emerging as promising nano-catalytic platforms. This Perspective highlights the recent advances in carbon dots synthesis and their applications in organic catalysis and photocatalysis, with particular attention to green non-metal-doped systems. Finally, forward-looking opportunities within this field are mentioned here.

Insight into the Multistate Emissive N, P‐doped Carbon Nano‐Onions: Emerging Visible‐Light Absorption for Photocatalysis

“…In recent years, carbon nanomaterials such as graphene, graphene oxide, nanodiamond, and their typical analogs in different dimensions (e. g.-carbon nanotubes, carbon dots, and carbon nano-onions), have drawn much attention from the scientific community due to their multimodal applicabilities in photonics, optoelectronics, catalytic and sensing devices. [1][2][3][4][5] Especially, carbon dots (CDs), are one kind of emerging carbonbased nanomaterials with excellent optical and fluorescence features with high quantum yield (QY) that have great potential in various applications including fluorescent probes, biological labeling, photocatalysis, and optoelectronic devices. [2][3][4]6] Furthermore, simple and low-cost preparation methods, high thermal and optical photostability, tunable excitation and emission features, easy surface functionalization, and environmental sustainability with high biocompatibility make them versatile materials in various fields.…”

Photon‐ and Charge‐Management in Advanced Energy Materials: Combining 0D, 1D, and 2D Nanocarbons as well as Bulk Semiconductors with Organic Chromophores

“…As a matter of fact, these were favored by their close proximity, which stem from their covalent attachment. Translation of these interactions to the excited state resulted in a 50% quenching of CND emissions and an 80% quenching of H 2 P fluorescence in the CNDH 2 P conjugate (28), in comparison to the individual components. Notable was a 6 nm red-shift of the H 2 P fluorescence features.…”

“…Strong intramolecular charge-transfer interactions were observed in CNDH 2 P conjugates (28), both in the ground and in the excited state, in H 2 O/THF 1:1 solutions- Figure 12. [115] The Soret-band absorptions of the H 2 P were found to be broadened and red-shifted by about 30 nm in comparison to a H 2 P-reference, and Q-band absorptions red-shift from 518, 555, 581, and 636 nm to 523, 556, 597, and 650 nm, respectively.…”

“…[115] The Soret-band absorptions of the H 2 P were found to be broadened and red-shifted by about 30 nm in comparison to a H 2 P-reference, and Q-band absorptions red-shift from 518, 555, 581, and 636 nm to 523, 556, 597, and 650 nm, respectively. Furthermore, CND-centered absorptions were subject to a 6 nm blue-shift in the CNDH 2 P conjugate (28), when compared with bare CNDs. These results pointed to strong electronic communications between the CNDs and H 2 P in the ground state.…”

“…Even after years of intense investigations, the mixing of 0D, 1D, and 2D nanocarbons, on one hand, and Ps, on the other hand, in advanced energy materials constitutes an interesting and challenging topic. [ 15–59 ] Often used in models for multistep electron transfer, the comprehensive understanding of electron donor‐acceptor interactions assists in paving the transformation towards artificial photosynthesis: efficient energy conversion and storage units. Considering today's call for alternative, renewable energy sources, efficient energy conversion, and storage units are of great relevance.…”