3 research outputs found
Porous Pt Nanotubes with High Methanol Oxidation Electrocatalytic Activity Based on Original Bamboo-Shaped Te Nanotubes
In
this report, a facile and general strategy was developed to
synthesize original bamboo-shaped Te nanotubes (NTs) with well-controlled
size and morphology. On the basis of the as-prepared Te NTs, porous
Pt nanotubes (NTs) with excellent property and structural stability
have been designed and manufactured. Importantly, we avoided the use
of surface stabilizing agents, which may affect the catalytic properties
during the templated synthesis process. Furthermore, Pt NTs with different
morphology were successfully prepared by tuning the experimental parameters.
As a result, transmission electron microscopy (TEM) study shows that
both Te NTs and Pt NTs have uniform size and morphology. Following
cyclic voltammogram (CV) testing, the as-prepared porous Pt NTs and
macroporous Pt NTs exhibited excellent catalytic activities toward
electrochemical methanol oxidation reactions due to their tubiform
structure with nanoporous framework. Thus, the as-prepared Pt NTs
with specific porous structure hold potential usage as alternative
anode catalysts for direct methanol fuel cells (DMFCs)
Sub-10 nm Sr<sub>2</sub>LuF<sub>7</sub>:Yb/Er@Sr<sub>2</sub>GdF<sub>7</sub>@SrF<sub>2</sub> Up-Conversion Nanocrystals for Up-Conversion Luminescence–Magnetic Resonance–Computed Tomography Trimodal Bioimaging
Herein, sub-10 nm
core–shell nanocrystals (NCs), which select Sr<sub>2</sub>LuF<sub>7</sub>:Yb/Er as core, Sr<sub>2</sub>GdF<sub>7</sub> as middle shell,
and SrF<sub>2</sub> as an outermost shell, were synthesized by a seed-mediated
growth process. The NCs possess good crystallinity, morphology, and
up-conversion luminescent properties. After modification by polyethylenimine
branched (PEI), in vitro cell up-conversion imaging with low autofluorescence
was realized. Due to the presence of Gd<sup>3+</sup> ions, in vivo
magnetic resonance (MR) imaging was also achieved with these designed
NCs. More significantly, these special core–shell NCs exhibited
high contrast in in vivo X-ray computed tomography (CT) imaging because
of their good X-ray absorption ability. These results indicate that
the core–shell up-conversion NCs can serve as promising contrast
agents for up-conversion luminescence–MR–CT trimodal
bioimaging
Application of Cu<sub>3</sub>InSnSe<sub>5</sub> Heteronanostructures as Counter Electrodes for Dye-Sensitized Solar Cells
In this research,
we reported the synthesis of quaternary Cu<sub>3</sub>InSnSe<sub>5</sub> nanoparticles with uniform size distribution and morphology for
the first time through delicate controls over the chemical reaction
kinetics. On the basis of the preparation strategy of Cu<sub>3</sub>InSnSe<sub>5</sub> nanoparticles, Pt–Cu<sub>3</sub>InSnSe<sub>5</sub> and Au–Cu<sub>3</sub>InSnSe<sub>5</sub> heteronanostructures
were designed and yielded using a simple and efficient seed growth
method. These two heteronanostructures remained monodispersed without
presence of any Cu<sub>3</sub>InSnSe<sub>5</sub> nanocrystal impurities.
To explore their application potentials for dye-sensitized solar cells,
counter electrodes consisting of individual Cu<sub>3</sub>InSnSe<sub>5</sub>, Pt–Cu<sub>3</sub>InSnSe<sub>5</sub>, or Au–Cu<sub>3</sub>InSnSe<sub>5</sub> constituents were fabricated. Current density–voltage
(<i>J</i>–<i>V</i>) characteristics evaluation
reveals that Cu<sub>3</sub>InSnSe<sub>5</sub> nanoparticles, Pt–Cu<sub>3</sub>InSnSe<sub>5</sub> and Au–Cu<sub>3</sub>InSnSe<sub>5</sub> heterostructured nanoparticles display a comparative power
conversion efficiency (PCE) of 5.8%, 7.6%, and 6.5% to that of a Pt-based
counter electrode (7.9%), respectively. As such, we believe that the
reported preparation strategy could provide new insights to the design
and manufacture of counter electrode materials with controlled structure,
morphology, and optimized power conversion efficiency for dye-sensitized
solar cells