We report supramolecular cross-linking of polymer binders via dynamic host-guest interactions between hyperbranched β-cyclodextrin polymer and a dendritic gallic acid cross-linker incorporating six adamantane units for high-capacity silicon anodes. Calorimetric analysis in the solution phase indicates that the given host-guest complexation is a highly spontaneous and enthalpically driven process. These findings are further verified by carrying out gelation experiments in both aqueous and organic media. The dynamic cross-linking process enables intimate silicon-binder interaction, structural stability of electrode film, and controlled electrode-electrolyte interface, yielding enhanced cycling performance. Control experiments using both α, γ-CDp with different cavity sizes and a guest molecule incorporating a single adamantane unit verified that the enhanced cycle life originates from the host-guest interaction between β-cyclodextrin and adamantane. The impact of the dynamic cross-linking is maximized at an optimal stoichiometry between the two components. Importantly, the present investigation proves that the molecular-level tuning of the host-guest interactions can be translated directly to the cycling performance of silicon anodes.

No abstract

Molecular doping, under certain circumstances, can be used to improve the charge transport in organic semiconductors through the introduction of excess charge carriers which can in turn negate unwanted trap states often present in organic semiconductors. Here, two Lewis basic indenopyrazine copolymers with large ionization potential (5.78 and 5.82 eV) are prepared to investigate the p-doping efficiency with the Lewis acid dopant, tris­(pentafluorophenyl)­borane, using organic thin-film transistors (OTFTs). The formation of Lewis acid–base complex between the polymer and dopant molecules is confirmed via optical spectroscopy and electrical field-effect measurements, with the latter revealing a dopant-concentration-dependent device performance. By adjusting the amount of p-dopant, the hole mobility can be increased up to 11-fold while the OTFTs’ threshold voltages are reduced. The work demonstrates an alternative doping mechanism other than the traditional charge transfer model, where the energy level matching principle can limit the option of dopants.

We report the first soluble poly(3-dodecyl tellurophenylenevinylene) and compare its properties to the analogous thiophene and selenophene containing polymers.

Precise fabrication of porous ternary Pt-based nanodendrites is very important for electrochemical energy conversion owing to high surface area and great molecular accessibility of these nanodendrites. Herein, PtPdRu porous nanodendrites (PNDs) were prepared via a facile one-step ultrasonic irradiation approach at room temperature. Intriguingly, the ultrasonic irradiation drove the formation of PtPdRu PNDs with spatially interconnected porous structures, whereas magnetic stirring produced PtPdRu nanoflowers (NFs) with less porosity. The formation mechanism was ascribed to the acoustic cavitation effect and fast-reduction kinetics under sonication. The as-made PtPdRu PNDs displayed a superior catalytic performance towards ethanol oxidation reaction with a high tolerance for CO-poisoning as compared to PtPdRu NFs, PtPd NDs, and commercial Pt/C catalyst.