Planar Heptathienoacenes Based on Unsymmetric Dithieno­[3,2‑<i>b</i>:3′,4′-d]­thiophene: Synthesis and Photophysical Properties

The unsymmetric dithieno­[3,2-<i>b</i>:3′,4′-<i>d</i>]­thiophene (<i><b>ts</b></i><b>-DTT</b>) was efficiently synthesized, and two novel hepta­thieno­acenes with linear and bull’s horn shapes were designed and prepared via different ring cyclization connection manners. All intermediates and aimed hepta­thieno­acenes were fully characterized by ¹H NMR, ¹³C NMR, and HRMS. Their UV–vis absorption behavior, fluorescence, and electrochemical properties are characterized. In addition, DFT quantum calculation was employed to further understand the electron distribution and the origin of the absorption bands

Synthesis of Novel Two-Phase Co@SiO₂ Nanorattles with High Catalytic Activity

Noble metal nanocatalysts with remarkable catalytic properties have attracted much attention; however, the high cost of these materials limits their industrial applications. Here, we design and prepare Co@SiO₂ nanorattles as a mixture of hcp-Co and fcc-Co phases as a substitute. The nanorattles exhibit both superior catalytic activity and high stability for the reduction of <i>p</i>-nitrophenol. The reduction rate nearly follows pseudo-first-order kinetics, and the reaction rate constant is as high as 0.815 min^–1 and is maintained at 0.565 min^–1 even after storing for one month, which is higher than that reported for noble metal nanocatalysts. Such an excellent property can be attributed to the novel two-phase composition and rattle-type structure

Morphology-Controllable Synthesis of Metal Organic Framework Cd₃[Co(CN)₆]₂·<i>n</i>H₂O Nanostructures for Hydrogen Storage Applications

In this paper, a potential strategy for increasing the hydrogen sorption has been demonstrated by using the nanostructure of metal organic framework. Prussian Blue analogue (PBA) Cd₃[Co­(CN)₆]₂·<i>n</i>H₂O nanocubes and octahedrons were successfully obtained at room temperature in the presence of poly­(vinylpyrrolidone) (PVP) and sodium dodecylbenzenesulfonate (SDBS), respectively. The as-prepared products were characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and thermogravimetric analysis (TGA). Detailed proof indicated that the synthetic parameters such as surfactant, the ratio of different solvents (water and ethanol) play crucial roles in the morphology and size of the nanoparticles. The fine-detailed information about porous structures of the samples has also been studied using the Brunauer–Emmet–Teller isotherm. Most importantly, two kinds of nanostructures both display high adsorption on H₂ and CO₂, showing enhanced adsorption properties compared with the bulk materials. To our knowledge, this is the first report on the synthesis of Cd₃[Co­(CN)₆]₂ nanomaterials and their H₂, CO₂ adsorption applications at the nanoscale

Co₃O₄ Nanocages for High-Performance Anode Material in Lithium-Ion Batteries

Co₃O₄ nanoparticles have been prepared by a facile strategy, which involves the thermal decomposition of nanoparticles of cobalt-based Prussian blue analogues at different temperatures. The nanoparticles prepared at 450, 550, 650, 750, and 850 °C exhibited a high discharge capacity of 800, 970, 828, 854, and 651 mAhg^–1, respectively, after 30 cycles at a current density of 50 mAg^–1. The nanocages produced at 550 °C show the highest lithium storage capacity. It is found that the nanocages display nanosize grains, hollow structure, a porous shell, and large specific surface area. At the temperature higher than 650 °C, the samples with larger grains, better crystallinity, and lower specific surface area can be obtained. It is found that the size, crystallinity, and morphology of nanoparticles have different effects on electrochemical performance. Better crystallinity is able to enhance the initial discharge capacity, while porous structure can reduce the irreversible loss. Therefore, the optimal size, crystallinity, and cage morphology are suggested to be responsible for the improved lithium storage capacity of the sample prepared at 550 °C. The as-prepared Co₃O₄ nanoparticles also have a potential application as anode material for Li-ion batteries due to their simple synthesis method and large capacity