The direct synthesis of monolayer and multilayer ReS2 by chemical vapor deposition at a low temperature of 450 °C is reported. Detailed characterization of this material is performed using various spectroscopy and microscopy methods. Furthermore initial field-effect transistor characteristics are evaluated, which highlight the potential in being used as an n-type semiconductor.

Carbon nanotubes can be chemically modified by attaching various functionalities to their surfaces, although harsh chemical treatments can lead to their break-up into graphene nanostructures. On the other hand, direct coupling between functionalities bound on individual nanotubes could lead to, as yet unexplored, spontaneous chemical reactions. Here we report an ambient mechano-chemical reaction between two varieties of nanotubes, carrying predominantly carboxyl and hydroxyl functionalities, respectively, facilitated by simple mechanical grinding of the reactants. The purely solid-state reaction between the chemically differentiated nanotube species produces condensation products and unzipping of nanotubes due to local energy release, as confirmed by spectroscopic measurements, thermal analysis and molecular dynamic simulations.

No abstract

Hybridizing faradaic and non‐faradaic charge storage mechanisms permits hybrid supercapacitors to achieve desirable high energy‐power characteristics. Although the hybridization approach increases the energy density, discrepancies in the reaction kinetics, especially sluggish charge‐transfer reactions in Faradaic battery‐type electrodes, curtails the power density. To increase the power density of battery‐type electrodes, an orthorhombic phase of niobium pentoxide (Nb2O5) is one of the most prominent contenders because the orthorhombic crystal structure provides two‐dimensional transport channels for fast Li‐ion diffusion. However, such ultrafast Li‐ion diffusion cannot be realized due to its electrical‐insulating nature. Herein, we synthesized a composite of the orthorhombic phase of niobium pentoxide (Nb2O5) interconnected with reduced graphene oxide nanosheets via facile microwave assisted methods. Such a dual‐conductive composite anode exhibits excellent rate performance to match that of the cathode which operates conventional adsorption‐desorption charge storage mechanism. By combining the composite anode with a nitrogen doped reduced graphene oxide (N‐rGO) cathode, the device delivers maximum energy density of 89 Wh kg−1 (at 125 W kg−1), and the energy density of 20 Wh kg−1 is retained even at 3500 W kg−1, which is one of the highest energy density reported for Nb2O5 based HSC to the best of our knowledge.

No abstract