Phonon Energy Transfer in Graphene–Photoacid Hybrids

Three water-soluble pyrene derivatives, i.e., 1-pyrenesulfonic acid sodium salt (PAS), 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt (HPTS), and 6,8-dihydroxy-1,3-pyrenedisulfonic acid disodium salt (DHPDS), were employed in noncovalent functionalization of graphene. The phonon coupling interaction between the HPTS and DHPDS photoacids and graphene was demonstrated by UV–vis and photoluminescence spectroscopies, and the proposed mechanism of the phonon transfer was verified by temperature-dependent absorption spectroscopy. Graphene plays the role as a modulator in these graphene/photoacid hybrid systems, which switches the equilibrium between different species of the photoacids. Current work presents the pioneering investigation of phonon coupling (phonon energy transfer) in the graphene–photoacid systems

Photoinduced Charge Transfer within Polyaniline-Encapsulated Quantum Dots Decorated on Graphene

A new method to enhance the stability of quantum dots (QDs) in aqueous solution by encapsulating them with conducting polymer polyaniline was reported. The polyaniline-encapsulated QDs were then decorated onto graphene through π–π interactions between graphene and conjugated polymer shell of QDs, forming stable polyaniline/QD/graphene hybrid. A testing electronic device was fabricated using the hybrid in order to investigate the photoinduced charge transfer between graphene and encapsulated QDs within the hybrid. The charge transfer mechanism was explored through cyclic voltammetry and spectroscopic studies. The hybrid shows a clear response to the laser irradiation, presenting a great advantage for further applications in optoelectronic devices