Self-Assembled Core-Shell CdTe/Poly(3-hexylthiophene) Nanoensembles as Novel Donor-Acceptor Light-Harvesting Systems.

The self-assembly of novel core-shell nanoensembles consisting of regioregular poly(3-hexylthiophene) nanoparticles (P3HT) of 100 nm as core and semiconducting CdTe quantum dots (CdTe) as shell with a thickness of a few tens of nanometers was accomplished by employing a reprecipitation approach. The structure, morphology, and composition of CdTe/P3HT nanoensembles were confirmed by high-resolution scanning transmission microscopy and dynamic light-scattering studies. Intimate interface contact between the CdTe shell and the P3HT core leads to the stabilization of the CdTe/P3HT nanoensemble as probed by the steady-state absorption spectroscopy.

Carbon quantum dots/block copolymer ensembles for metal-ion sensing and bioimaging.

Fluorescent carbon quantum dots (CQDs) rich in amine moieties that can be easily protonated under acidic conditions were electrostatically interacted with diblock copolymer poly[sodium(carboxylate sulfamate) isoprene]-b-poly(ethylene oxide) (CSS-IEO-3) possessing negatively charged sulfamate and carboxylate species on the CSS part of the diblock copolymer. The so-formed CQDs/CSS-IEO-3 material was found to be stable in a neutral and high salinity environment, which is critical when aiming for biological applications. Moreover, the photoluminescence of CQDs within CQDs/CSS-IEO-3, with emission at 420 nm upon excitation at 320 nm, was unaffected by pH and salinity changes, denoting the absence of significant aggregation phenomena and highlighting the potential of CQDs/CSS-IEO-3 for bioimaging.

Mechanistic insights into the photocatalytic properties of metal nanocluster/graphene ensembles. Examining the role of visible light in the reduction of 4-nitrophenol.

Metal nanoclusters (M) based on silver and gold, abbreviated as Ag and Au, respectively, were synthesized and combined with functionalized graphene, abbreviated as f-G, forming novel M/f-G ensembles. The preparation of M/f-G was achieved by employing attractive electrostatic interactions developed between negatively charged M, attributed to the presence of carboxylates due to α-lipoic acid employed as a stabilizer, and positively charged f-G, attributed to the presence of ammonium units as addends. The realization of M/f-G ensembles was established via titration assays as evidenced by electronic absorption and photoluminescence spectroscopy as well as scanning transmission electron microscopy (STEM) and energy-dispersive X-ray (EDX) spectroscopy analyses.

Transition-Metal Chalcogenide/Graphene Ensembles for Light-Induced Energy Applications.

Recently, nanomaterials that harvest solar energy and convert it to other forms of energy are of great interest. In this context, transition metal chalcogenides (TMCs) have recently been in the spotlight due to their optoelectronic properties that render them potential candidates mainly in energy conversion applications. Integration of TMCs onto a strong electron-accepting material, such as graphene, yielding novel TMC/graphene ensembles is of high significance, since photoinduced charge-transfer phenomena, leading to intra-ensemble charge separation, may occur.

Single-Step Functionalization and Exfoliation of Graphene with Polymers under Mild Conditions.

The simultaneous polymer functionalization and exfoliation of graphene sheets by using mild bath sonication and heat treatment at low temperature is described. In particular, free-radical polymerization of three different vinyl monomers takes place in the presence of graphite flakes. The polymerization procedure leads to the exfoliation of graphene sheets and at the same time the growing polymer chains are attached onto the graphene lattice, which gives solubility and stability to the final graphene-based hybrid material.