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Prashant V. Kamat

Bio: Prashant V. Kamat is an academic researcher from University of Notre Dame. The author has contributed to research in topics: Racism & Excited state. The author has an hindex of 140, co-authored 725 publications receiving 79259 citations. Previous affiliations of Prashant V. Kamat include Indian Institute of Technology Kanpur & Council of Scientific and Industrial Research.


Papers
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TL;DR: The photophysical properties of a series of red-sensitive, highly fluorescent bis[4-(monoaza-crown ether)-phenyl]squaraine fluoroionophores are reported in this article.
Abstract: The photophysical properties of a series of red-sensitive, highly fluorescent bis[4-(monoaza-crown ether)-phenyl]squaraine fluoroionophores are reported. These dyes are soluble in both polar and nonpolar solvents with fluorescence quantum yield varying from 0.01 to 0.85. These dyes readily form aggregates in aqueous solutions. These aggregates dissociate in [beta]-cyclodextrin solutions as the dye molecules form 1:1 complex with [beta]-cyclodextrin. This complexation process is accompanied by a significant enhancement in the fluorescence yields of these dyes. Complexation of the fluoroionophores with alkali-metal ions brings about drastic reductions in their fluorescence quantum yield as well as significant changes in their redox properties. 35 refs., 9 figs., 3 tabs.

79 citations

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TL;DR: In this paper, the kinetics and mechanism of a diffusion-controlled interfacial charge transfer between excited triplet thionine and ZnO colloids in ethanol have been elucidated with laser flash photolysis.
Abstract: The kinetics and mechanism of a diffusion-controlled interfacial charge transfer between excited triplet thionine and ZnO colloids in ethanol have been elucidated with laser flash photolysis. The singlet excited state of thionine, which has a lifetime of 450 ps in ethanol, did not participate in the charge injection process. However, the triplet excited state of thionine was quenched by ZnO colloids. The triplet lifetime ({tau}{sub T}) decreased from 88 to 15 {mu}s with increasing ZnO colloid concentration. The maximum charge injection efficiency ({theta}{sub TH{center_dot}}2+) which was measured from the yield of dye cation radical was 0.1. The increase in the rate constant for reverse electron transfer (k{sub r}) at high ZnO concentration resulted in a small decrease in charge-transfer efficiency. The dependence of {tau}{sub T}, {theta}{sub TH{center_dot}}2+, and k{sub r} on the concentration of ZnO is described. 49 refs., 9 figs.

78 citations

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TL;DR: In this paper, carbon nanotubes have emerged as new architectures for designing light-harvesting assemblies and they have been used as photoresponsive electrode materials and their role in the conversion of light energy into electricity is discussed.

78 citations

Journal ArticleDOI
TL;DR: In this paper, a modification of a previous synthesis for the formation of GaAs nanocrystals is reported, which produces quantized GaAs colloids which do not also contain molecular species which interfere with the optical properties of the GaAs particles.
Abstract: A modification of a previous synthesis for the formation of GaAs nanocrystals is reported. Unlike the previous synthesis, the new procedure produces quantized GaAs colloids which do not also contain molecular species which interfere with the optical properties of the GaAs particles. The GaAs colloids have been characterized by transmission electron microscopy, electron diffraction, ultrafiltration, absorption and photoluminescence spectroscopy, and transient pumpprobe spectroscopy; these experiments indicate that the particles have a size ranging from 20 to 80 A

78 citations

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TL;DR: In this paper, the Pt-SiO 2 composite particles of ratio 1:1 and 2:1 showed superior performance towards oxygen reduction reaction (ORR) as these composite particles formed an interconnected particle-network and maximize the available electrochemically active area.

78 citations


Cited by
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[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

Journal ArticleDOI
TL;DR: Two organolead halide perovskite nanocrystals were found to efficiently sensitize TiO(2) for visible-light conversion in photoelectrochemical cells, which exhibit strong band-gap absorptions as semiconductors.
Abstract: Two organolead halide perovskite nanocrystals, CH3NH3PbBr3 and CH3NH3PbI3, were found to efficiently sensitize TiO2 for visible-light conversion in photoelectrochemical cells. When self-assembled on mesoporous TiO2 films, the nanocrystalline perovskites exhibit strong band-gap absorptions as semiconductors. The CH3NH3PbI3-based photocell with spectral sensitivity of up to 800 nm yielded a solar energy conversion efficiency of 3.8%. The CH3NH3PbBr3-based cell showed a high photovoltage of 0.96 V with an external quantum conversion efficiency of 65%.

16,634 citations

Journal ArticleDOI
TL;DR: This work reviews the historical development of Transition metal dichalcogenides, methods for preparing atomically thin layers, their electronic and optical properties, and prospects for future advances in electronics and optoelectronics.
Abstract: Single-layer metal dichalcogenides are two-dimensional semiconductors that present strong potential for electronic and sensing applications complementary to that of graphene.

13,348 citations

Journal ArticleDOI
TL;DR: A review of gold nanoparticles can be found in this article, where the most stable metal nanoparticles, called gold colloids (AuNPs), have been used for catalysis and biology applications.
Abstract: Although gold is the subject of one of the most ancient themes of investigation in science, its renaissance now leads to an exponentially increasing number of publications, especially in the context of emerging nanoscience and nanotechnology with nanoparticles and self-assembled monolayers (SAMs). We will limit the present review to gold nanoparticles (AuNPs), also called gold colloids. AuNPs are the most stable metal nanoparticles, and they present fascinating aspects such as their assembly of multiple types involving materials science, the behavior of the individual particles, size-related electronic, magnetic and optical properties (quantum size effect), and their applications to catalysis and biology. Their promises are in these fields as well as in the bottom-up approach of nanotechnology, and they will be key materials and building block in the 21st century. Whereas the extraction of gold started in the 5th millennium B.C. near Varna (Bulgaria) and reached 10 tons per year in Egypt around 1200-1300 B.C. when the marvelous statue of Touthankamon was constructed, it is probable that “soluble” gold appeared around the 5th or 4th century B.C. in Egypt and China. In antiquity, materials were used in an ecological sense for both aesthetic and curative purposes. Colloidal gold was used to make ruby glass 293 Chem. Rev. 2004, 104, 293−346

11,752 citations

Journal ArticleDOI
Ryoji Asahi1, Takeshi Morikawa1, T. Ohwaki1, Koyu Aoki1, Y. Taga1 
13 Jul 2001-Science
TL;DR: Film and powders of TiO2-x Nx have revealed an improvement over titanium dioxide (TiO2) under visible light in optical absorption and photocatalytic activity such as photodegradations of methylene blue and gaseous acetaldehyde and hydrophilicity of the film surface.
Abstract: To use solar irradiation or interior lighting efficiently, we sought a photocatalyst with high reactivity under visible light. Films and powders of TiO 2- x N x have revealed an improvement over titanium dioxide (TiO 2 ) under visible light (wavelength 2 has proven to be indispensable for band-gap narrowing and photocatalytic activity, as assessed by first-principles calculations and x-ray photoemission spectroscopy.

11,402 citations