Assessing the Photoinduced Electron-Donating Behavior of Carbon Nanodots in Nanoconjugates

Abstract

Carbon nanodots (CNDs) undergo electron transfer in different scenarios. Previous studies have mainly focused on the electron-accepting features of CNDs in covalently linked donor–acceptor nanoconjugates. In view of this, we decided to carry out in this study the formation of covalently linked nanoconjugates that feature electron-donating pressure synthesized carbon nanodots (pCNDs) and electron-accepting 11,11,12,12-tetracyano-9,10-anthra-p-quinodimethane (TCAQ): pCND-TCAQ. The stability of the one-electron reduced form of TCAQ renders it the acceptor of choice. Detailed structural and electrochemical investigations allowed the characterization of pCND-TCAQ. Furthermore, investigations regarding intramolecular interactions, by means of steady-state and pump–probe transient absorption spectroscopies, allowed detection and characterization of three excited state species, in general, and the pCND •+ -TCAQ •– charge-separated state, in particular.

Amino Modified Carbon Dots with Electron Sink Effect Increase Interface Charge Transfer Rate of Cu‐Based Electrocatalyst to Enhance the CO2 Conversion Selectivity to C2H4

“…[27][28][29][30] CDs can be used as excellent electron donors or electron acceptors, which can effectively regulate the electron transport behavior in the composite system, and ultimately achieve the improvement of catalytic performance. [31][32][33] In our previous works, the combination of CDs and polyoxometalates (POMs) can effectively enhance the electron capture ability of Pt atoms in POMs and accelerate the electron transfer rate, thus enhancing the kinetic process of hydrogen oxidation reaction (HOR). [34] Furthermore, CDs can act as an electron storage container to capture the electrons from PtNi 2 and release them to the carrier, thus enhancing the catalytic activity of HOR by regulating the interface charge kinetics.…”

Interfacing Carbon Dots for Charge‐Transfer Processes

“…On the exploration of the electron donating properties of CDs, electron-accepting 11,11,12,12-tetracyano-9,10-anthrap-quinodimethane (TCAQ) hydroxyl-terminated units where covalently introduced on the surface of carboxylic acid-rich carbon dots (pCNDs) via a common esterification reaction. [53] Both electrochemical (square wave voltammetry) and photophysical studies (photoluminescence emission and transient absorption spectroscopy) unveiled an intrahybrid charge separation yielding the pCND •+ -TCAQ •− charge-separated state. Notably, physical mixing of the two components (1:5 and 5:1 ratios) failed to yield charge separation, highlighting the role of their covalent association.…”

Carbon Nanodots for All-in-One Photocatalytic Hydrogen Generation

“…This motivated the exploration of CNDs in the fields of imaging, sensing, lighting, etc. − CNDs were integrated into solar energy conversion schemes and probed in energy and charge transfer reactions. At the forefront of these investigations were covalent − and noncovalent − electron donor–acceptor systems involving, for example, pressure-synthesized CNDs (pCNDs). Common to these studies is the fact that they are the first steps toward a full-fledged understanding of the (photo)­catalytic performance of CNDs in energy conversion schemes. − In terms of HER photocatalysis, CNDs have mainly served as photosensitizers, in combination with nickel − /cobalt complexes, redox enzymes, , or TiO 2 nanotubes , as catalysts .…”