Nanoparticles Prepared by Salt Vapor-Solvent Vapor Cocondensation and Controlled Nucleation: Metal Sulfides (ZnS, CdS, CdSe, PbS), and Metal Halide (LiF). Size, Aggregates, Structures, Digestive Ripening, Superlattices, and Impregnations

2007 ◽  
Vol 17 (17) ◽  
pp. 3562-3568 ◽  
Author(s):  
D. Heroux ◽  
A. Ponce ◽  
S. Cingarapu ◽  
K. J. Klabunde
Keyword(s):  
Metal Halide ◽  
Metal Sulfides ◽  
Solvent Vapor ◽  
Digestive Ripening ◽  
Controlled Nucleation

scholarly journals Reversible multicolor chromism in layered formamidinium metal halide perovskites

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Bryan A. Rosales ◽  
Laura E. Mundt ◽  
Taylor G. Allen ◽  
David T. Moore ◽  
Kevin J. Prince ◽  
...  
Keyword(s):  
Energy Input ◽  
Formation Energy ◽  
Optoelectronic Devices ◽  
Metal Halide ◽  
Electronic Band ◽  
Solvent Vapor ◽  
Number Of Layers ◽  
Yellow Orange ◽  
Halide Perovskites ◽  
Electronic Band Structures

Abstract Metal halide perovskites feature crystalline-like electronic band structures and liquid-like physical properties. The crystal–liquid duality enables optoelectronic devices with unprecedented performance and a unique opportunity to chemically manipulate the structure with low energy input. In this work, we leverage the low formation energy of metal halide perovskites to demonstrate multicolor reversible chromism. We synthesized layered Ruddlesden-Popper FAn+1PbnX3n+1 (FA = formamidinium, X = I, Br; n = number of layers = 1, 2, 3 … ∞) and reversibly tune the dimensionality (n) by modulating the strength and number of H-bonds in the system. H-bonding was controlled by exposure to solvent vapor (solvatochromism) or temperature change (thermochromism), which shuttles FAX salt pairs between the FAn+1PbnX3n+1 domains and adjacent FAX “reservoir” domains. Unlike traditional chromic materials that only offer a single-color transition, FAn+1PbnX3n+1 films reversibly switch between multiple colors including yellow, orange, red, brown, and white/colorless. Each colored phase exhibits distinct optoelectronic properties characteristic of 2D superlattice materials with tunable quantum well thickness.

Scanning Electron Microscope Study of Bacteria on Mineral Surfaces

1976 ◽  
Vol 34 ◽  
pp. 130-131
Author(s):  
V.K. Berry
Keyword(s):  
Oxidation Reaction ◽  
Electron Microscope Study ◽  
Elemental Sulfur ◽  
Thiobacillus Ferrooxidans ◽  
Physical Contact ◽  
Metal Sulfides ◽  
Low Grade ◽  
Mineral Surfaces ◽  
Mineral Surface ◽  
Scanning Electron Microscope Study

There are two strains of bacteria viz. Thiobacillus thiooxidansand Thiobacillus ferrooxidanswidely mentioned to play an important role in the leaching process of low-grade ores. Another strain used in this study is a thermophile and is designated Caldariella .These microorganisms are acidophilic chemosynthetic aerobic autotrophs and are capable of oxidizing many metal sulfides and elemental sulfur to sulfates and Fe2+ to Fe3+. The necessity of physical contact or attachment by bacteria to mineral surfaces during oxidation reaction has not been fairly established so far. Temple and Koehler reported that during oxidation of marcasite T. thiooxidanswere found concentrated on mineral surface. Schaeffer, et al. demonstrated that physical contact or attachment is essential for oxidation of sulfur.

Identification of acid-insoluble filter-plugging compounds and optimal acid-washing procedures for tubular backpulse pressure filters

TAPPI Journal ◽  
2011 ◽  
Vol 10 (1) ◽  
pp. 17-23
Author(s):  
KEVIN TAYLOR ◽  
RICH ADDERLY ◽  
GAVIN BAXTER
Keyword(s):  
Calcium Sulfate ◽  
Membrane Filter ◽  
Sulfamic Acid ◽  
Xrd Analysis ◽  
Metal Sulfides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gypsum Formation ◽  
Acid Washing ◽  
Hydrolysis Of

Over time, performance of tubular backpulse pressure filters in kraft mills deteriorates, even with regular acid washing. Unscheduled filter replacement due to filter plugging results in significant costs and may result in mill downtime. We identified acid-insoluble filter-plugging materials by scanning electron microscope/energy-dispersion X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis in both polypropylene and Gore-Tex™ membrane filter socks. The major filter-plugging components were calcium sulfate (gypsum), calcium phosphate (hydroxylapatite), aluminosilicate clays, metal sulfides, and carbon. We carried out detailed sample analysis of both the standard acid-washing procedure and a modified procedure. Filter plugging by gypsum and metal sulfides appeared to occur because of the acid-washing procedure. Gypsum formation on the filter resulted from significant hydrolysis of sulfamic acid solution at temperatures greater than 130°F. Modification of the acid-washing procedure greatly reduced the amount of gypsum and addition of a surfactant to the acid reduced wash time and mobilized some of the carbon from the filter. With surfactant, acid washing was 95% complete after 40 min.

Evaluation of Therapeutic Effectiveness of Photodynamic Therapy (PDT) Using Metal Halide Lamp for Actinic Keratosis and Bowen's Disease

2011 ◽  
Vol 73 (3) ◽  
pp. 260-265
Author(s):  
Toshinori BITO ◽  
Shun OHMORI ◽  
Mayuko YOSHIZAWA ◽  
Sanehito HARUYAMA ◽  
Yu SAWADA ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Actinic Keratosis ◽  
Metal Halide ◽  
Therapeutic Effectiveness ◽  
Bowen’S Disease ◽  
Bowen's Disease ◽  
Metal Halide Lamp

Hollow Metal Halide Perovskite Nanocrystals with Efficient Blue Emissions

2019 ◽  
Author(s):  
Michael Worku ◽  
Yu Tian ◽  
Chenkun Zhou ◽  
Haoran Lin ◽  
Maya Chaaban ◽  
...  
Keyword(s):  
Precursor Solution ◽  
Visible Spectral Region ◽  
Metal Halide ◽  
Synthetic Control ◽  
Perovskite Nanocrystals ◽  
Highly Efficient ◽  
Quantum Confinement Effects ◽  
Metal Halide Perovskite ◽  
Lead Bromide ◽  
Halide Perovskite

Metal halide perovskite nanocrystals (NCs) have emerged as a new generation light emitting materials with narrow emissions and high photoluminescence quantum efficiencies (PLQEs). Various types of perovskite NCs, e.g. platelets, wires, and cubes, have been discovered to exhibit tunable emissions across the whole visible spectral region. Despite remarkable advances in the field of metal halide perovskite NCs over the last few years, many nanostructures in inorganic NCs have yet been realized in metal halide perovskites and producing highly efficient blue emitting perovskite NCs remains challenging and of great interest. Here we report for the first time the discovery of highly efficient blue emitting cesium lead bromide perovskite (CsPbBr3) NCs with hollow structures. By facile solution processing of cesium lead bromide perovskite precursor solution containing additional ethylenediammonium bromide and sodium bromide, in-situ formation of hollow CsPbBr3 NCs with controlled particle and pore sizes is realized. Synthetic control of hollow nanostructures with quantum confinement effects results in color tuning of CsPbBr3 NCs from green to blue with high PLQEs of up to 81 %.<br><div><br></div>

Lead-Free Metal Halide Perovskite Nanocrystals for Photocatalysis in Water

2019 ◽  
Author(s):  
Subhajit Bhattacharjee ◽  
Sonu Pratap Chaudhary ◽  
Sayan Bhattacharyya
Keyword(s):  
Charge Carrier ◽  
Wide Spectrum ◽  
Real Life ◽  
Metal Halide ◽  
Lead Free ◽  
Water Medium ◽  
Type I ◽  
Type Ii ◽  
Perovskite Layer ◽  
Halide Perovskites

<p>Metal halide perovskites with high absorption coefficient, direct generation of free charge carriers, excellent ambipolar charge carrier transport properties, point-defect tolerance, compositional versatility and solution processability are potentially transforming the photovoltaics and optoelectronics industries. However their limited ambient stability, particularly those of iodide perovskites, obscures their use as photocatalysts especially in aqueous medium. In an unprecedented approach we have exploited the photo-absorption property of the less toxic lead-free Cs<sub>3</sub>Bi<sub>2</sub>X<sub>9 </sub>(X = Br, I) nanocrystals (NCs) to catalyse the degradation of water pollutant organic dye, methylene blue (MB) in presence of visible light at room temperature. After providing a proof-of-concept with bromide perovskites in isopropanol, the perovskites are employed as photocatalysts in water medium by designing perovskite/Ag<sub>2</sub>S and perovskite/TiO<sub>2 </sub>composite systems, with Type I (or quasi Type II) and Type II alignments, respectively. Ag<sub>2</sub>S and TiO<sub>2</sub> coatings decelerate penetration of water into the perovskite layer while facilitating charge carrier extraction. With a minimal NC loading, Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub>/Ag<sub>2</sub>S degrades ~90% MB within an hour. Our approach has the potential to unravel the photocatalytic properties of metal halide perovskites for a wide spectrum of real-life applications. </p>

Epitaxial Metal Halide Perovskites by InkJet Printing

2019 ◽  
Author(s):  
Mykhailo Sytnyk ◽  
Ole Lytken ◽  
Tim Freund ◽  
Wolfgang Heiss ◽  
Christina Harreiss ◽  
...  
Keyword(s):  
Inkjet Printing ◽  
Metal Halide ◽  
Halide Perovskites
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