Nano rutile, anatase, and bicrystalline (anatase + brookite) titania powders with an average crystal size of below 10 nm are prepared from aqueous TiOCl(2) solution at low temperatures by adjusting pH values of the starting solution and adding different additives. Adding a small amount of octyl phenol poly(ethylene oxide) into aqueous TiOCl(2) solution leads to the change of particle morphologies of obtained nano titania from needlelike to nano spherical rutile crystals. Amorphous-anatase transformation of titania could proceed in liquid-solid reaction at low temperatures, even at room temperature. A formation mechanism of rutile, anatase, and brookite titania was proposed. It is found that H(+) or H(3)O(+) plays a catalytic role in the phase transformation from amorphous to anatase titania and that the presence of a small amount of SO(4)(2)(-) ion is unfavorable to the formation of both rutile and brookite. By carefully adjusting preparation conditions, nano pure anatase with higher surface area, good crystallinity, and a lower recombination rate of photoexcited electrons and holes was obtained. This nano pure anatase showed a very good photocatalytic activity for gas-phase photo-oxidation of benzene.
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http://dx.doi.org/10.1021/la0489716 | DOI Listing |
Langmuir
January 2025
Research Center for Water Resources and Interface Science, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China.
The mechanism of the emulsion polymerization of styrene to polystyrene nanoparticles (PSNPs) remains a subject of debate. Herein, a series of reaction parameters with different surfactant concentrations, monomer contents, temperatures, and equilibration times were investigated to understand the formation mechanism of PSNPs, which demonstrate a correlation between the properties of PSNPs and the mesostructure of the premix. Cooling the model systems with self-emulsifying nanodroplets (SENDs) in the early reaction stages resulted in the hollow polystyrene spheres (H-PSSs), ruptured PSNPs, and dandelion-like PSNPs, further indicating that the oil nanodroplets are the key sites for the formation of PSNPs.
View Article and Find Full Text PDFInorg Chem
January 2025
Department of Chemistry, University of Patras, Patras 265 04, Greece.
A new [DyBiOCl(saph)] () Werner-type cluster has been prepared, which is the first Dy/Bi polynuclear compound with no metal-metal bond and one of the very few Ln-Bi (Ln = lanthanide) heterometallic complexes reported to date. The molecular compound has been deliberately transformed to its 1-D analogue [DyBiO(N)(saph)] () via the replacement of the terminal Cl ions by end-to-end bridging N groups. The overall metallic skeleton of (and ) can be described as consisting of a diamagnetic {Bi} unit with an elongated trigonal bipyramidal topology, surrounded by a magnetic {Dy} equilateral triangle, which does not contain μ-oxo/hydroxo/alkoxo groups.
View Article and Find Full Text PDFSmall Methods
January 2025
BCMaterials, Basque Centre for Materials, Applications and Nanostructures; UPV/EHU Science Park, Leioa, 48940, Spain.
Carbon coating on SiO surface is crucial for enhancing initial Coulombic efficiency (ICE) and cycling performance in batteries, while also buffering volume expansion. Despite its market prevalence, the effects of the carbon layer's quality and structure on the electrochemical properties of SiO remain underexplored. This study compares carbon layers produced via gas-phase and solid-phase coating methods, introducing an innovative technique that sequentially uses two gases to develop a low-impedance hybrid carbon structure.
View Article and Find Full Text PDFIn July 2022 southeast England experienced a record breaking heatwave and unprecedented wildfires in urban areas. We investigate fire weather trends since 1960 in southeast England using a large ensemble of initialised climate models. Record smashing temperatures coincided with widespread fires in London, and we find that while wildfire risk was high, it was not record breaking.
View Article and Find Full Text PDFJ Mamm Evol
January 2025
Department of Chemical and Biological Sciences, Youngstown State University, Youngstown, OH USA.
Unlabelled: Remains of megatheres have been known since the 18th -century and were among the first megafaunal vertebrates to be studied. While several examples of preserved integument show a thick coverage of fur for smaller ground sloths living in cold climates such as and , comparatively very little is known about megathere skin. Assuming a typical placental mammal metabolism, it was previously hypothesized that megatheres would have had little-to-no fur as they achieved giant body sizes.
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