Open AccessUltrafast Interface Charge Separation in Carbon Nanodot–Nanotube Hybrids
Author(s) -
Alice Sciortino,
Francesco Ferrante,
Gil Gonçalves,
Stefania Sandoval,
Radian Popescu,
D. Gerthsen,
Nicolò Mauro,
Gaetano Giammona,
Gianpiero Buscarino,
F. M. Gelardi,
S. Agnello,
Marco Cannas,
Dario Duca,
Fabrizio Messina
Publication year - 2021
Publication title -
acs applied materials and interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.535
H-Index - 228
eISSN - 1944-8252
pISSN - 1944-8244
DOI - 10.1021/acsami.1c16929
Subject(s) - materials science , carbon nanotube , electron transfer , nanotechnology , photoluminescence , photoinduced charge separation , delocalized electron , carbon nanobud , nanodot , photocatalysis , nanotube , optical properties of carbon nanotubes , optoelectronics , artificial photosynthesis , photochemistry , biochemistry , chemistry , physics , quantum mechanics , catalysis
Carbon dots are an emerging family of zero-dimensional nanocarbons behaving as tunable light harvesters and photoactivated charge donors. Coupling them to carbon nanotubes, which are well-known electron acceptors with excellent charge transport capabilities, is very promising for several applications. Here, we first devised a route to achieve the stable electrostatic binding of carbon dots to multi- or single-walled carbon nanotubes, as confirmed by several experimental observations. The photoluminescence of carbon dots is strongly quenched when they contact either semiconductive or conductive nanotubes, indicating a strong electronic coupling to both. Theoretical simulations predict a favorable energy level alignment within these complexes, suggesting a photoinduced electron transfer from dots to nanotubes, which is a process of high functional interest. Femtosecond transient absorption confirms indeed an ultrafast (<100 fs) electron transfer independent of nanotubes being conductive or semiconductive in nature, followed by a much slower back electron transfer (≈60 ps) from the nanotube to the carbon dots. The high degree of charge separation and delocalization achieved in these nanohybrids entails significant photocatalytic properties, as we demonstrate by the reduction of silver ions in solution. The results are very promising in view of using these "all-carbon" nanohybrids as efficient light harvesters for applications in artificial photocatalysis and photosynthesis.