ABSTRACT: Ultrathin single-crystalline V(2) O(5) ·0.76H(2) O nanosheets with a thickness of 1.5-2.6 nm are prepared on the basis of molecular-level 'oriented attachment' through special sol-gel chemistry. The initial formation of 3-7 nm nanodiscs by confining the condensation reactions within the ab plane is critical to form nanosheets. As a proof-of-concept, these nanosheets exhibit good properties for hydrogen sensors and supercapacitors.
Small 11/2012; · 8.35 Impact Factor
ABSTRACT: Few layered graphene oxide (GO) nanosheets with large specific surface area (42.1 m2 g−1) are successfully
prepared by a modified Hummers method for use as electrodes in the vanadium bromide redox
battery. The structure and physicochemical properties of GO are investigated by X-ray diffraction, Raman
spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron
microscopy, and atomic force microscopy. Cyclic voltammetry results indicate that GO nanosheets
with polymer binder (i.e., polyvinylidiene fluoride (PVDF) or sulfonated poly(ether ether ketone) (SPEEK))
hybrids demonstrate more favorable electrocatalytic activity towards the Br−/Br3− and V3+/V2+ redox
couples than the pure graphite. This is attributed to the large numbers of oxygen-containing functional
groups on the GO nanosheet surface which can generate more active sites to catalyze the redox reactions.
For the binder-based electrodes, the SPEEK based electrode gives the best electrochemical performance
(e.g., lower overvoltage for both Br−/Br3− and V3+/V2+ redox couple reactions and higher peak currents
for the V3+/V2+ redox couple).
Electrochimica Acta 01/2012; 85(2012):175-181. · 3.83 Impact Factor
ABSTRACT: CuInSe(2) (CIS) nanodandelion structures were synthesized by a two-step solvothermal approach. First, InSe nanodandelions were prepared by reacting In(acac)(3) with trioctylphosphine-selenide (TOP-Se) in 1-octadecene (ODE) at 170 °C in the presence of oleic acid. These InSe dandelions were composed of polycrystalline nanosheets with thickness < 10 nm. The size of the InSe dandelions could be tuned within the range of 300 nm-2 µm by adjusting the amount of oleic acid added during the synthesis. The InSe dandelion structures were then reacted with Cu(acac)(2) in the second-step solvothermal process in ODE to form CIS nanodandelions. The band gap of the CIS dandelions was determined from ultraviolet (UV) absorption measurements to be ∼ 1.36 eV, and this value did not show any obvious change upon varying the size of the CIS dandelions. Brunauer-Emmett-Teller (BET) measurements showed that the specific surface area of these CIS dandelion structures was 44.80 m(2) g(-1), which was more than five times higher than that of the CIS quantum dots (e.g. 8.22 m(2) g(-1)) prepared by using reported protocols. A fast photoresponsive behavior was demonstrated in a photoswitching device using the 200 nm CIS dandelions as the active materials, which suggested their possible application in optoelectronic devices.
Nanotechnology 05/2011; 22(19):195607. · 3.98 Impact Factor