2 research outputs found
Solar-to-Electric Performance Enhancement by Titanium Oxide Nanoparticles Coated with Porous Yttrium Oxide for Dye-Sensitized Solar Cells
TiO<sub>2</sub>–Y<sub>2</sub>O<sub>3</sub> core–shell
nanoparticles for dye-sensitized solar cells (DSSCs) have been fabricated
by a solvothermal technique. The heterostructure of TiO<sub>2</sub> nanoparticles coated with porous Y<sub>2</sub>O<sub>3</sub> is confirmed
with transmission electron microscopy. The bonding of the Y<sub>2</sub>O<sub>3</sub> coating on the TiO<sub>2</sub> surface is quantitatively
analyzed in terms of the Lifshitz–van der Waals and electrostatic
contributions to the surface free energy of the particles. TiO<sub>2</sub> and Y<sub>2</sub>O<sub>3</sub> constitute a core–shell
heterojunction because the Fermi levels merge; this increases the
open-circuit voltage. Higher recombination resistances are obtained
in DSSCs with porous Y<sub>2</sub>O<sub>3</sub>-coated TiO<sub>2</sub> compared with those in the reference cells, indicating “backscattering”
inhibition of the porous Y<sub>2</sub>O<sub>3</sub> barrier on TiO<sub>2</sub> nanoparticles. Moreover, smaller transport resistances and
longer electron lifetimes are achieved in DSSCs with TiO<sub>2</sub>–Y<sub>2</sub>O<sub>3</sub> core–shell nanoparticles.
Compared with a reference cell, the <i>V</i><sub>OC</sub> of a DSSC with a partial Y<sub>2</sub>O<sub>3</sub> coating on the
surface of the TiO<sub>2</sub> nanoparticles improves from 683 to
738 mV and the <i>J</i><sub>sc</sub> from 14.15 to 15.35
mA·cm<sup>–2</sup>, whereas the conversion efficiency
increases by 15.2%
Chrysamides A–C, Three Dimeric Nitrophenyl <i>trans</i>-Epoxyamides Produced by the Deep-Sea-Derived Fungus <i>Penicillium chrysogenum</i> SCSIO41001
Three dimeric nitrophenyl <i>trans</i>-epoxyamides, chrysamides
A–C (<b>1</b>–<b>3</b>), were obtained from
the deep-sea-derived fungus <i>Penicillium chrysogenum</i> SCSIO41001. Their structures were characterized by spectroscopic
analysis, electronic circular dichroism computations, and X-ray single-crystal
diffraction analysis. Notably, compound <b>1</b> possesses a
novel centrosymmetric dimer skeleton featuring an unprecedented 7-oxa-2,5-diazabicyclo[2.2.1]Âheptane
ring system, which represents the first example of dimeric nitrophenyl <i>trans</i>-epoxyamide in nature. Compound <b>3</b> suppresses
the production of proinflammatory cytokine interleukin-17. A possible
biosynthetic pathway of <b>1</b>–<b>3</b> was proposed