Leu-M

Lithium–sulfur batteries are amongst the most promising candidates to satisfy emerging energy-storage demands. Suppression of the polysulfide shuttle while maintaining high sulfur content is the main challenge that faces their practical development. Here, we report that 2D early-transition-metal carbide conductive MXene phases—reported to be impressive supercapacitor materials—also perform as excellent sulfur battery hosts owing to their inherently high underlying metallic conductivity and self-functionalized surfaces. We show that 70 wt % S/Ti2C composites exhibit stable long-term cycling performance because of strong interaction of the polysulfide species with the surface Ti atoms, demonstrated by X-ray photoelectron spectroscopy studies. The cathodes show excellent cycling performance with specific capacity close to 1200 mA h g−1 at a five-hour charge/discharge (C/5) current rate. Capacity retention of 80 % is achieved over 400 cycles at a two-hour charge/discharge (C/2) current rate.

Sulfur Cathodes Based on Conductive MXene Nanosheets for High-Performance Lithium–Sulfur Batteries

Nearly monodisperse single-crystalline Cu2O nanospheres were prepared by an effective solution method with NaBH4 as the reducing agent. Sensors based on them have good sensitivity to some flammable gases because thin films formed by nanospheres have capacious interspaces and enough spherical surfaces to interact with gases (ppm level).

Nearly Monodisperse Cu2O and CuO Nanospheres: Preparation and Applications for Sensitive Gas Sensors

The aim of this review article on recent developments of mechanochemistry (nowadays established as a part of chemistry) is to provide a comprehensive overview of advances achieved in the field of atomistic processes, phase transformations, simple and multicomponent nanosystems and peculiarities of mechanochemical reactions. Industrial aspects with successful penetration into fields like materials engineering, heterogeneous catalysis and extractive metallurgy are also reviewed. The hallmarks of mechanochemistry include influencing reactivity of solids by the presence of solid-state defects, interphases and relaxation phenomena, enabling processes to take place under non-equilibrium conditions, creating a well-crystallized core of nanoparticles with disordered near-surface shell regions and performing simple dry time-convenient one-step syntheses. Underlying these hallmarks are technological consequences like preparing new nanomaterials with the desired properties or producing these materials in a reproducible way with high yield and under simple and easy operating conditions. The last but not least hallmark is enabling work under environmentally friendly and essentially waste-free conditions (822 references).

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Hallmarks of mechanochemistry: From nanoparticles to technology

Hydrothermal technology for nanotechnology

Closed PbS nanowires with regular geometric morphologies (ellipse and parallelogram shape) were synthesized in the presence of poly[N-(2-aminoethyl)acrylamide] in ethylenediamine/H2O (3∶1, v/v) solvent at 110–150 °C.

Synthesis of closed PbS nanowires with regular geometric morphologies

Single-crystal, metastable, hexagonal In2O3 (H-In2O3) nanofibers with an average diameter of 80 nm and length of up to several micrometers were synthesized on a large scale, for the first time under ambient pressure, by annealing InOOH nanofibers at 490 °C. The InOOH nanofibers were prepared by a controlled hydrolysis solvothermal reaction, using InCl3·4H2O as the starting material and ether as the solvent, in the temperature range of 190–240 °C. The solvent has significant effects on the formation of the metastable phase and the morphology of the In2O3 nanocrystals during the synthesis of the precursor InOOH. Room-temperature optical absorption spectra of the hexagonal In2O3 nanofibers showed strong absorption peak located at 325 nm (3.83 eV) with a slight blue-shift compared with that of bulk In2O3 (3.75 eV). The H-In2O3 nanofibers photoluminesce at room temperature with emission peaks at 378 nm, 398 nm, and 420 nm. The successful production of metastable hexagonal In2O3 nanofibers in large scale under mild conditions could be of interest both for applications and fundamental studies.

Metastable Hexagonal In2O3 Nanofibers Templated from InOOH Nanofibers under Ambient Pressure

Uniform crystalline Cu2O cubes were synthesized in high yield by reducing the copper−citrate complex solution with glucose. A series of shape evolutions of Cu2O particles from the transient species such as multi-pod and star-shaped particles to cubic crystals have been arrested based on TEM and SEM observation. The higher growth rate along 〈111〉 induces the shrinking of the eight {111} faces, while six {100} faces remained to form Cu2O cubes because of their lower growth rate. The experimental results suggest that the building blocks with desired architecture can be selectively synthesized by programming the growth parameters in the initial synthetic scheme.

Dabin Yu

Papers

Synthesis of closed PbS nanowires with regular geometric morphologies

Metastable Hexagonal In2O3 Nanofibers Templated from InOOH Nanofibers under Ambient Pressure

Large-Scale Growth and Shape Evolution of Cu2O Cubes

Preparation and characterization of wire-like Sb2Se3 and flake-like Bi2Se3 nanocrystals

Synthesis of ITO nanowires and nanorods with corundum structure by a co-precipitation-anneal method