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.

Dye Loaded Polymer Electrodes III . Generation of Photogalvanic Effects at Electrodes Coated with Poly(4‐Vinyl Pyridine) Films Containing Rose Bengal

Abstract: Des electrodes de SnO 2 , conductrices, prerecouvertes de poly(vinyl-4 pyridine) peuvent fixer electrostatiquement un colorant anionique, le rose bengale, dans la matrice polymere protonee. Lorsque cette electrode modifiee est plongee dans une solution aqueuse contenant un couple redox convenable et illuminee dans la bande d'absorption du colorant, il y a generation d'effets photo―electrochimiques

Polymer-modified electrodes. Electrochemical and photoelectrochemical polymerization of 1-vinylpyrene

Abstract: Polymerization of 1-vinylpyrene in acetonitrile was achieved electrochemically at a conducting SnO/sub 2/ electrode by application of anodic potentials and photoelectrochemically at a n-GaAs semiconductor electrode under visible light irradiation. Both polymers exhibited characteristic excimer emission ..lambda../sub max approx. 480 nm) in both films and THF solutions similar to poly(vinylpyrene) synthesized by using Ziegler-Natta catalyst. The lifetime of the excimer emission was approx.110 ns. The mechanism of photodegradation of poly(vinylpyrene) was elucidated by using ESR techniques. 22 references, 7 figures, 1 table.

GaAs Quantum Dots

Abstract: GaAs quantum dots have been prepared by reacting gallium acetylacetonate with trimethylsilylarsine in triethylene glycol ether at 216 K. The colloidal dispersion of GaAs nanocrystals has been characterized by transmission electron microscopy, electron diffraction, ultrafiltration, optical absorption and photoluminescence spectroscopy, and transient pump-probe spectroscopy; the spectral data were also fitted to a model that accounts for the size-dependent optical properties of a Gaussian distribution of particle sizes. Our results indicate that the spectral region above 470 nm can be assigned solely to GaAs nanocrystals having a mean diameter of 40.0 A with a standard deviation of 9.7 A. The origin of spectral features below 470 nm has not yet been determined conclusively.

Unusual electrocatalytic behavior of ferrocene bound fullerene cluster films

Abstract: Fullerene clusters containing a redox couple (ferrocene) have been assembled as nanostructured films on conducting glass and carbon electrodes using an electrophoretic approach. These films show irreversibility in the reduction waves when the electrochemical scan is limited to cathodic cycles (potential range of 0 to −0.8 V versus SCE). However, the reversibility in the cyclic voltammograms can be restored by extending the scans to the anodic region (+0.75 to −0.8 V versus SCE). The ferrocene couple reoxidizes the stabilized C60 anion–tetrabutylammonium complex in the cluster assembly during the oxidation cycle. We present here a simple approach of incorporating a redox active species for improving the electrochemical activity of fullerene films. The electrochemical measurements that illustrate the electrocatalytic property of C60 cluster films are described.

Quantum Dots Continue to Shine Brightly

Abstract: F more than 2 decades, research on semiconductor nanocrystals (NCs), also known as colloidal quantum dots (QDs), has dominated the field of Nanoscience. The ability to tune the optical and electronic properties through size and shape control has made this field attractive and has stimulated studies of new applications. The five most cited papers in physical chemistry show the early impact of this discipline in diverse areas. A lot of early effort has focused on binary semiconductors such as CdSe, CdS, CdTe, ZnSe, PbSe, and PbS as they are easy to synthesize and characterize. These materials have been further modifiedin some cases profoundlyby combining them into NC heterostructures. Various semiconductor NCs have been extensively explored as light energy harvesters and emitters. Specifically, these materials were advocated for solar cells, photocatalysis, display devices, photodetectors, and photostable luminescent labels. Despite the progress made toward large-scale synthesis of these materials, this early class of NCs failed to attract as much consideration for practical applications as projected, mainly for fear of the heavy metal content. The impact of semiconductor NC research can be visualized from the number of published papers and their citations to-date for individual years (Figure 1). The initial growth in published

I and i

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 …

Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells

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%.

Electronics and optoelectronics of two-dimensional transition metal dichalcogenides.

Abstract: Single-layer metal dichalcogenides are two-dimensional semiconductors that present strong potential for electronic and sensing applications complementary to that of graphene.

Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology.

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

Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides

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.