Synthesis of an indium oxide nanoparticle embedded graphene three-dimensional architecture for enhanced lithium-ion storage

Indium oxide nanoparticles were synthesised by using a facile and scalable strategy. The as-prepared nanoparticles (20-40 nm) were in situ and homogeneously distributed in a three-dimensional (3D) graphene architecture subsequently during the fabrication process. The obtained nanocomposite acts as a high capacity anode material for lithium-ion batteries and demonstrates good cycle stability. A drastically enhanced capacity of 750 mA h g^-1 in comparison with that of bare In2O3 nanoparticles can be maintained after 100 cycles, along with an improved high rate performance (210 mA h g^-1 at 1 A g^-1 and 120 mA h g^-1 at 2 A g^-1). The excellent performance is linked with the indium oxide nanoparticles and the unique 3D interconnected porous graphene structure. The highly conductive and porous 3D graphene structure greatly enhances the performance of lithium-ion batteries by protecting the nanoparticles from the electrolyte, stabilizing the nanoparticles during cycles and buffering the volume expansion upon lithium insertion.

GaN and Gax In1-x N nanoparticles with tunable indium content: synthesis and characterization

Semiconducting GaN and Gax In1-x N nanoparticles (4-10 nm in diameter, depending on the metal ratio) with tunable indium content are prepared through a chemical synthesis (the urea-glass route). The bandgap of the ternary system depends on its composition, and therefore, the color of the final material can be turned from bright yellow (the color of pure GaN) to blue (the color of pure InN). Transmission electron microscopy (TEM and HRTEM) and scanning electron microscopy (SEM) images confirm the nanoparticle character and homogeneity of the as-prepared samples. X-ray diffraction (XRD), electron diffraction (EDX), elemental mapping, and UV/Vis, IR, and Raman spectroscopy investigations are used to confirm the incorporation of indium into the crystal structure of GaN. These nanoparticles, possessing adjusted optical properties, are expected to have potential applications in the fabrication of novel optoelectronic devices.

Frontispiece: GaN and Gax In1-x N nanoparticles with tunable indium content: synthesis and characterization

Optoelectronic Devices A captivating peculiarity of GaInN alloys is a tunable band gap, depending on the Ga/In ratio, where the pure nitrides are bright yellow (GaN) or dark blue (InN). Gax In1-x N nanoparticles were prepared by a bottom-up approach (the urea glass route). The incorporation of an increasing amount of indium in the GaN structure is indicated by different colors (i.e., different band gaps), and the alloys are further investigated by TEM and optical microscopy. More information can be found in the Full Paper by C. Giordano et al. on page 18976 ff.

pH-detachable polymer brushes formed using titanium−diol coordination chemistry and living radical polymerization (RAFT)

pH-detachable poly(styrene) brushes formed on indium−tin oxide (ITO) glass substrates using metal complex chemistry and reversible addition−fragmentation chain transfer (RAFT) polymerization was described. These pH-detachable polymeric brushes were generated using both “graft-from” and “graft-to” methodologies. The methodologies involved either the surface self-assembly of catechol-functional RAFT agents (graft-from) or catechol-terminal polymer chains (graft-to) onto the ITO substrate via titanium−diol coordination. The stepwise functionalization of the ITO glass surfaces was characterized successfully using X-ray photoelectron spectroscopy (XPS) and contact angle measurement. Poly(styrene) brushes generated using the “graft-from” method were denser than those generated using the “graft-to” method, as exemplified by atom force microscopy (AFM) and quantified using cyclic voltammetry. Poly(styrene) brushes assembled using both methods could be detached easily by manipulating the pH of the brush environment. Cyclic voltammetry was utilized to calculate precisely the surface coverage of the RAFT functionality and polymeric brush density.

Large-scale production of h-In2O3/carbon nanocomposites with enhanced lithium storage properties

h-In2O3/carbon nanocomposites were obtained via a facile ball milling process from a mixture of h-In2O3 nanoparticles and Super P carbon. Compared to pure h-In2O3 nanoparticles, the nanocomposites exhibited an initial discharge capacity of 1360 mAh g-1, a stable reversible capacity of 867 mAh g-1 after 100 cycles as well as a high coulombic efficiency of 99%. The superior lithium-ion battery performance can be attributed to the specific structure of h-In2O3 and the uniform and continuous nano-carbon coating layers. The nano-carbon coating could protect the inner active materials from fragmentation and increase the electronic conductivity. This study not only provides a promising electrode material for high-performance lithium-ion batteries, but also further demonstrates a straightforward, effective and environmental friendly process for synthesizing nanocomposites. © 2014 Elsevier Ltd.

Synthesis and structure of three molecular arylindium phosphinates

Reported here are the syntheses and molecular structures of three novel arylindium phosphinates, [(2,6-Mes₂C₆H₃In)₂(OH)₂(O₂PMe₂)₂] (1), [(2,6-Mes₂C₆H₃In)₂(OH) (O₂PPh₂)₃] (2), and [(2,6-Mes₂C₆H₃In)(O₂PMe₅C₃H)₂(H₂O)₂] (3), which were obtained by condensation reaction of the m-terphenylindium dihydroxide [(2,6-Mes₂C₆H₃In(OH)₂]₄with dimethylphosphinic acid, diphenylphosphinic acid, and ,2,3,4,4-pentamethylphosphetanic acid, respectively.

One-step synthesis of graphene quantum dots from defective CVD graphene and their application in IGZO UV thin film phototransistor

Chemical vapor deposition (CVD) has recently been considered as the most reliable method to prepare high-quality monolayer graphene films, yet the as-grown graphene usually contains wrinkles and cracks or suffers from discontinuity. These defects can easily result in the shredding of large-sized graphene into small pieces even under a gentle disturbance. Herein, this work presents a cost-effective new method to produce high-quality GQDs by vigorous sonication of defective CVD graphene. The prepared GQDs can be easily and stably dispersed in organic solvents. Morphology and optical properties of the GQDs are investigated using a number of techniques. And we observed the as-prepared GQDs are highly homogeneous, mostly consisted of single-layered graphene, roughly round shapes less than 8 nm in a diameter, and exhibited a strong blue luminescence. Impressively, it is also confirmed that the as-obtained GQDs can act as a promising light absorption material for phototransistor with a hybrid film of GQDs and indium gallium zinc oxide (IGZO) as the channel layer. The GQD/IGZO phototransistor exhibited an appreciated photocurrent, which is 10 times larger than that of the IGZO one when exposed to 270 nm light.