Spatial Distribution of Active Sites for Plasmon-Induced Chemical Reactions Triggered by Well-Defined Plasmon Modes

Nanoscale ◽  
2021 ◽  
Author(s):  
Hiro Minamimoto ◽  
Takahiro Toda ◽  
Kei Murakoshi
Keyword(s):  
Spatial Distribution ◽  
Energy Conversion ◽  
Chemical Reactions ◽  
Active Sites ◽  
Near Infrared ◽  
Oxidative Polymerization ◽  
Conductive Polymer ◽  
Infrared Light ◽  
Light Illumination ◽  
Plasmon Modes

Plasmon-induced chemical reactions triggered by near-infrared light illumination might enable efficient photo energy conversion. Here, electrochemical oxidative polymerization of a conductive polymer is conducted on plasmonic photoconversion electrodes. The absolute...

Spatial distribution of active sites on a ferroelectric PbTiO3 photocatalyst for photocatalytic hydrogen production

2017 ◽  
Vol 198 ◽  
pp. 463-472 ◽  
Author(s):  
Rengui Li ◽  
Yue Zhao ◽  
Can Li
Keyword(s):  
Spatial Distribution ◽  
Hydrogen Production ◽  
Solar Energy ◽  
Energy Conversion ◽  
Electric Fields ◽  
Charge Separation ◽  
Active Sites ◽  
Solar Energy Conversion ◽  
Photogenerated Electrons ◽  
The Right

The separation of photogenerated charge carries is a challenging issue in artificial photocatalyst systems for solar energy conversion. It has been reported that spatial charge separation can take place between different facets of semiconductor-based crystals with regular morphology and facets, which could be used to rationally deposit cocatalysts on the right facets. However, the spatial separation of photogenerated electrons and holes is still a big challenge for a particulate photocatalyst without regular morphology and specific facets. In this work, we demonstrated that photogenerated electrons and holes can be regularly separated on ferroelectric PbTiO3 photocatalyst even without regular morphology and facets. The reduction cocatalyst and oxidation cocatalyst could be selectively formed on different sites via an in situ photochemical deposition method. It is found that the photoactivity and hydrogen production for PbTiO3 with spatially separated dual-cocatalysts is remarkably enhanced to more than 100 times greater compared to native PbTiO3, which is much higher than that the case of dual-cocatalysts with a random distribution. The intrinsic electric fields and spontaneous electric polarization in the bulk of PbTiO3 are proposed to play important roles in the spatial distribution of active sites on irregular PbTiO3 particles. Our work emphasizes the essential roles of two important factors, efficient charge separation strategy and the location of dual-cocatalysts on the right sites, to construct integrated artificial photocatalyst systems for solar energy conversion.

scholarly journals High Resolution NIR Imaging of the Starburst Galaxy NGC 1808

1994 ◽  
Vol 159 ◽  
pp. 461-461
Author(s):  
L.E. Tacconi-Garman ◽  
A. Krabbe ◽  
A. Sternberg ◽  
R. Genzel
Keyword(s):  
Star Formation ◽  
Hot Spots ◽  
Active Sites ◽  
Near Infrared ◽  
Large Fraction ◽  
Line Emission ◽  
Far Infrared ◽  
Infrared Light ◽  
Continuum Emission ◽  
Starburst Galaxy

We report 0.6″ res. J, H, and K and 1.5″ res. imaging of 2.17 μm HI Brγ and 2.12 μm H2 1-0 S(1) line emission towards the nucleus of the starburst galaxy NGC 1808. In the K-band data we (partially) resolve the nucleus and see several small knots in the circumnuclear region. Further, our JHK continuum images show that a large fraction of the near infrared light in NGC 1808 is produced in young star forming clusters. The Brγ emission originates from a compact nuclear source and from several distinct emission knots in the circumnuclear region. These knots are spatially well correlated with a family of compact radio sources, but uncorrelated with the optical “hot spots”. We propose that the Brγ knots trace the actual sites of starburst activity, while the optical hot spots are just directions of low foreground extinction.We use our data together with radio and far-infrared continuum emission measurements to constrain the parameters of the individual starburst sites in NGC 1808. The data suggest that the starbursts are unsynchronized and prolonged (5 × 106–5 × 107 yrs). The star formation rates in the active sites range from ∼0.1 to ∼0.6 M⊙ yr−1, and the present rapid rate of star-formation in NGC 1808 can be maintained for at most another ∼7 × 107 yrs.Portions of this work are presently in press (Krabbe, Sternberg, and Genzel 1993), and a second paper is in preparation (Tacconi-Garman et al. 1993).

scholarly journals Facile synthesis of P(EDOT/Ani) : PSS with enhanced heat shielding efficiency via two-stage shot growth

RSC Advances ◽  
2018 ◽  
Vol 8 (23) ◽  
pp. 12992-12998 ◽  
Author(s):  
Chanil Park ◽  
Soeun Im ◽  
Wonseok Cho ◽  
Yunryeol Kim ◽  
Jung Hyun Kim
Keyword(s):  
Near Infrared ◽  
Oxidative Polymerization ◽  
Infrared Light ◽  
Facile Synthesis ◽  
Two Stage ◽  
Near Infrared Light ◽  
Styrene Sulfonate ◽  
Enhanced Absorption ◽  
Heat Shielding ◽  
Poly Styrene Sulfonate

Poly(3,4-ethylenedioxythiophene/aniline) : poly(styrene sulfonate), P(EDOT/Ani) : PSS, with enhanced absorption of near infrared light, was prepared by oxidative polymerization.

scholarly journals Synthesis of a Smart Conductive Block Copolymer Responsive to Heat and Near Infrared Light

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1744 ◽  
Author(s):  
Silvestre Bongiovanni Abel ◽  
Kevin Riberi ◽  
Claudia R. Rivarola ◽  
Maria Molina ◽  
Cesar A. Barbero
Keyword(s):  
Block Copolymer ◽  
Near Infrared ◽  
Local Heating ◽  
Oxidative Polymerization ◽  
Polymerization Reaction ◽  
Infrared Light ◽  
Solution Temperature ◽  
Synthetic Approach ◽  
Nir Light ◽  
Nir Absorption

A method for the synthesis of a linear block copolymer (PNIPAM-b-PANI), containing a thermoresponsive block (poly(N-isopropylacrylamide), PNIPAM) and a Near Infrared (NIR) light-absorbing block (polyaniline, PANI), is reported. The synthetic approach involves a two-step successive polymerization reaction. First, the radical polymerization of NIPAM is done using 4-aminothiophenol as a chain transfer agent for the obtention of thermosensitive block terminated with an aniline (ANI) moiety. Second, the oxidative polymerization of ANI is initiated in ANI moiety of thermosensitive block to grow the second conductive PANI block. 1H nuclear magnetic resonance (NMR) and FT-IR spectroscopy shows the characteristics peaks of both polymeric blocks revealing the successful copolymerization process. Static Light Scattering (SLS) and UV-Visible combined measurements allowed the determination of the Mw for PNIPAM-b-PANI macromolecule: 5.5 × 105 g mol−1. The resulting copolymer is soluble in water (8.3 g L−1) and in non-aqueous solvents, such as ethanol, formic acid, acetonitrile, and others. Both polymer blocks chains show the properties of the polymer chains. The block copolymer shows a lower critical solution temperature (LCST) at the same temperature (32–34 °C) than PNIPAM, while the copolymer shows pH dependent UV-vis-NIR absorption similar to PANI. The PNIPAM block suffers a coil to globule transition upon NIR light irradiation (785 nm, 100 mW), as shown by turbidimetry and Atomic Force Microscopy (AFM), due to local heating (more than 9 °C in 12 min) induced by the NIR absorption at the PANI block. Furthermore, the electrical conductivity of PNIPAM-b-PANI thin films is demonstrated (resistivity of 5.3 × 10−4 Ω−1 cm−1), indicating that the PANI block is present in its conductive form.

scholarly journals Thin MAPb0.5Sn0.5I3 Perovskite Single Crystals for Sensitive Infrared Light Detection

2022 ◽  
Vol 9 ◽  
Author(s):  
Jinming Wu ◽  
Yongqiang Zhang ◽  
Shuang Yang ◽  
Zhaolai Chen ◽  
Wei Zhu
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Near Infrared ◽  
High Sensitivity ◽  
Fast Response ◽  
Low Noise ◽  
Infrared Light ◽  
Light Illumination ◽  
Lead Iodide ◽  
Methylammonium Lead Iodide

Metal halide perovskite single-crystal detectors have attracted increasing attention due to the advantages of low noise, high sensitivity, and fast response. However, the narrow photoresponse range of widely investigated lead-based perovskite single crystals limit their application in near-infrared (NIR) detection. In this work, tin (Sn) is incorporated into methylammonium lead iodide (MAPbI3) single crystals to extend the absorption range to around 950 nm. Using a space-confined strategy, MAPb0.5Sn0.5I3 single-crystal thin films with a thickness of 15 μm is obtained, which is applied for sensitive NIR detection. The as-fabricated detectors show a responsivity of 0.514 A/W and a specific detectivity of 1.4974×1011 cmHz1/2/W under 905 nm light illumination and –1V. Moreover, the NIR detectors exhibit good operational stability (∼30000 s), which can be attributed to the low trap density and good stability of perovskite single crystals. This work demonstrates an effective way for sensitive NIR detection.

scholarly journals Towards near-infrared photosensitization of tungsten trioxide nanostructured films by upconverting nanoparticles

RSC Advances ◽  
2015 ◽  
Vol 5 (100) ◽  
pp. 81875-81880 ◽  
Author(s):  
Frédéric Venne ◽  
Marta Quintanilla ◽  
Francis Quenneville ◽  
Dilek Işik ◽  
Bill Baloukas ◽  
...  
Keyword(s):  
Thin Films ◽  
Solar Energy ◽  
Metal Oxide ◽  
Energy Conversion ◽  
Tungsten Trioxide ◽  
Near Infrared ◽  
Infrared Light ◽  
Nanostructured Films ◽  
Semiconducting Thin Films ◽  
Nanostructured Metal

Upconverting nanoparticles are explored in the field of solar energy conversion to extend the light harvesting properties of nanostructured metal oxide semiconducting thin films to near infrared light.

Fluorescent proteins for in vivo imaging, where's the biliverdin?

2020 ◽  
Vol 48 (6) ◽  
pp. 2657-2667
Author(s):  
Felipe Montecinos-Franjola ◽  
John Y. Lin ◽  
Erik A. Rodriguez
Keyword(s):  
Hydrogen Peroxide ◽  
In Vivo Imaging ◽  
Near Infrared ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Fluorescent Imaging ◽  
Infrared Light ◽  
Red Fluorescent Protein ◽  
Color Palette

Noninvasive fluorescent imaging requires far-red and near-infrared fluorescent proteins for deeper imaging. Near-infrared light penetrates biological tissue with blood vessels due to low absorbance, scattering, and reflection of light and has a greater signal-to-noise due to less autofluorescence. Far-red and near-infrared fluorescent proteins absorb light >600 nm to expand the color palette for imaging multiple biosensors and noninvasive in vivo imaging. The ideal fluorescent proteins are bright, photobleach minimally, express well in the desired cells, do not oligomerize, and generate or incorporate exogenous fluorophores efficiently. Coral-derived red fluorescent proteins require oxygen for fluorophore formation and release two hydrogen peroxide molecules. New fluorescent proteins based on phytochrome and phycobiliproteins use biliverdin IXα as fluorophores, do not require oxygen for maturation to image anaerobic organisms and tumor core, and do not generate hydrogen peroxide. The small Ultra-Red Fluorescent Protein (smURFP) was evolved from a cyanobacterial phycobiliprotein to covalently attach biliverdin as an exogenous fluorophore. The small Ultra-Red Fluorescent Protein is biophysically as bright as the enhanced green fluorescent protein, is exceptionally photostable, used for biosensor development, and visible in living mice. Novel applications of smURFP include in vitro protein diagnostics with attomolar (10−18 M) sensitivity, encapsulation in viral particles, and fluorescent protein nanoparticles. However, the availability of biliverdin limits the fluorescence of biliverdin-attaching fluorescent proteins; hence, extra biliverdin is needed to enhance brightness. New methods for improved biliverdin bioavailability are necessary to develop improved bright far-red and near-infrared fluorescent proteins for noninvasive imaging in vivo.

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