Three‐dimensional porous Sb/Sb2O3 anode materials are successfully fabricated using a simple electrodeposition method with a polypyrrole nanowire network. The Sb/Sb2O3–PPy electrode exhibits ...excellent cycle performance and outstanding rate capabilities; the charge capacity is sustained at 512.01 mAh g−1 over 100 cycles, and 56.7% of the charge capacity at a current density of 66 mA g−1 is retained at 3300 mA g−1. The improved electrochemical performance of the Sb/Sb2O3–PPy electrode is attributed not only to the use of a highly porous polypyrrole nanowire network as a substrate but also to the buffer effects of the Sb2O3 matrix on the volume expansion of Sb. Ex situ scanning electron microscopy observation confirms that the Sb/Sb2O3–PPy electrode sustains a strong bond between the nanodeposits and polypyrrole nanowires even after 100 cycles, which maintains good electrical contact of Sb/Sb2O3 with the current collector without loss of the active materials.
A 3D porous Sb/Sb2O3–PPy electrode exhibits excellent cycle performance and outstanding rate capabilities due to not only high porosity of the polypyrrole nanowire network but also the buffer effects of the Sb2O3 matrix on the volume expansion of Sb.
Few-Layer Antimonene by Liquid-Phase Exfoliation Gibaja, Carlos; Rodriguez-San-Miguel, David; Ares, Pablo ...
Angewandte Chemie (International ed.),
November 7, 2016, Letnik:
55, Številka:
46
Journal Article
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We report on a fast and simple method to produce highly stable isopropanol/water (4:1) suspensions of few‐layer antimonene by liquid‐phase exfoliation of antimony crystals in a process that is ...assisted by sonication but does not require the addition of any surfactant. This straightforward method generates dispersions of few‐layer antimonene suitable for on‐surface isolation. Analysis by atomic force microscopy, scanning transmission electron microscopy, and electron energy loss spectroscopy confirmed the formation of high‐quality few‐layer antimonene nanosheets with large lateral dimensions. These nanolayers are extremely stable under ambient conditions. Their Raman signals are strongly thickness‐dependent, which was rationalized by means of density functional theory calculations.
Very stable suspensions of high‐quality single‐ or few‐layer antimonene were obtained by liquid‐phase exfoliation under sonication without the need for a surfactant. The Raman spectrum of antimonene was found to strongly depend on its thickness, which was also rationalized by quantum‐mechanical calculations.
Catalysis with Pnictogen, Chalcogen, and Halogen Bonds Benz, Sebastian; Poblador‐Bahamonde, Amalia I.; Low‐Ders, Nicolas ...
Angewandte Chemie (International ed.),
May 4, 2018, Letnik:
57, Številka:
19
Journal Article
Recenzirano
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Halogen‐ and chalcogen‐based σ‐hole interactions have recently received increased interest in non‐covalent organocatalysis. However, the closely related pnictogen bonds have been neglected. In this ...study, we introduce conceptually simple, neutral, and monodentate pnictogen‐bonding catalysts. Solution and in silico binding studies, together with high catalytic activity in chloride ion reactions, yield compelling evidence for operational pnictogen bonds. The depth of the σ holes is easily varied with different substituents. Comparison with homologous halogen‐ and chalcogen‐bonding catalysts shows an increase in activity from main group VII to V and from row 3 to 5 in the periodic table. Pnictogen bonds from antimony thus emerged as by far the best among the elements covered, a finding that provides most intriguing perspectives for future applications in catalysis and beyond.
Antimony is the winner—perhaps surprisingly, perhaps not—of a comparative evaluation of the σ‐hole interactions of various pnictogen‐, chalcogen‐, and halogen‐bonding donors in anion binding and catalysis, with the strength decreasing according to Sb>Te>I>As>Se>Br, P. Catalysis with pnictogen bonds is reported for the first time.
Two hybrid chloroantimonates(III), Bzmim3SbCl6 (1, Bzmim=1‐benzyl‐3‐methylimidazolium, Tm1=410 K) and Bzmim2SbCl5 (2, Tm2=348 K) are presented. 1 exhibits green emission (quantum efficiency of 87.5 ...%); 2 exhibits blue and red emissions under the irradiation of 310 and 396 nm light, respectively. Using different cooling methods, crystalline 1 and IL@2 (IL=ionic liquid of BzmimCl) could be generated from the molten 1. Reversible structural and PL transformation triggered by moisture or heat was observed between 1 and IL@2. Such PL switching, combined with the crystallization‐induced PL properties of 1 and 2, resulted in the firstly reported triple‐mode reversible PL switching, that is, on–off (T>Tm1), color switching (T<Tm2), and on–off–on (Tm2<T<Tm1). Furthermore, ink‐ and mask‐free laser‐printable rewritable PL paper was achieved. This study demonstrates the promise of dynamic insertion/extraction of ILs in hybrid chloroantimonates for anti‐counterfeiting and rewritable PL paper.
Fancy paper: Reversible thermally induced triple‐mode photoluminescent (PL) switching including the novel on–off–on mode on two hybrid chloroantimonates(III) is reported. These results show the great promise of the dynamic insertion/extraction of ionic liquids in hybrid chloroantimonates(III) in anti‐counterfeiting and rewritable PL paper.
Antimony (Sb) is an attractive anode material for sodium-ion batteries (SIBs) with a high theoretical capacity of 660 mAh g −1 . However, its practical application is greatly hindered by the rapid ...capacity fading which is largely due to the large volume expansion during sodiation. Tuning the morphology and structure at the nanoscale or using carbonaceous materials as the buffer layer is essential to address this issue. Here, a facile carbon-coating coupled with a thermal-reduction strategy has been developed to synthesize unique Sb@C coaxial nanotubes. With different annealing time, the hollow space and the amount of Sb inside the tube can be easily tuned by the partial evaporation of Sb. The as-obtained Sb@C nanotubes exhibit excellent sodium storage properties. The remarkable electrochemical performance results from the unique coaxial nanoarchitecture. Specifically, it delivers a high specific capacity of 407 mAh g −1 at 100 mA g −1 after 240 cycles. Furthermore, a stable capacity of 240 mAh g −1 can be retained at 1.0 A g −1 even after 2000 cycles. Most importantly, high capacities of 350 mAh g −1 and 310 mAh g −1 can be achieved at large current densities of 10 and 20 A g −1 , respectively, which represents the best rate performance among the reported Sb-based anode materials.
A significant amount of antimony (Sb) enters into the environment every year because of the wide use of Sb compounds in industry and agriculture. The exposure to Sb, either direct consumption of Sb ...or indirectly, may be fatal to the human health because both antimony and antimonide are toxic. Firstly, the introduction of Sb chemistry, distribution and health threats are presented in this review, which is essential to the removal techniques. Then, we provide the recent and common techniques to remove Sb, including adsorption, coagulation/flocculation, membrane separation, electrochemical methods, ion exchange and extraction. Removal techniques concentrate on the advantages, drawbacks, economical efficiency and the recent achievements of each technique. We also take an overall consideration of experimental conditions, comparison criteria, and economic aspects.
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•The Sb contamination emerges as a serious threat.•Various techniques are used for Sb contamination removal.•Adsorption methods show superiority in the removal of Sb under commercial scale.•Integrated utilization of new techniques is needed.
A novel noncentrosymmetric (NCS) polar fluoride sulfate, CsSbF2SO4, was obtained by ionothermal synthesis. A meticulously designed co‐substitution approach was used to successfully replace the TiO68− ...and PO43− functional groups in KTiOPO4 (KTP) with SbO4F27− and SO42− units, respectively. The structure of CsSbF2SO4 features a pseudo‐3D framework consisting of interconnected 1D SbF2O2SO45− chains of corner‐sharing SbO4F27− octahedra and SO42− tetrahedra. The title compound exhibits a sharply enlarged band gap compared to its parent compound, KTP, benefitting from the introduction of F− ions and the displacement of Sb3+ cations. Second harmonic generation (SHG) measurements manifested that CsSbF2SO4 is phase‐matchable and revealed a strong SHG response of about 3.0 KH2PO4 (KDP), which is the highest value reported for any metal sulfate reported to date. The reported fluoride sulfate is a promising near ultraviolet (UV) nonlinear optical (NLO) material.
The fluoride sulfate CsSbF2SO4 was obtained from KTiOPO4 by chemical co‐substitution of the TiO68− and PO43− functional groups in KTiOPO4 with SbO4F27− and SO42− units. CsSbF2SO4 features a significantly wider energy band gap than KTiOPO4 and a strong second harmonic generation response.
Pure micrometric antimony can be successfully used as negative electrode material in Na-ion batteries, sustaining a capacity close to 600 mAh g–1 at a high rate with a Coulombic efficiency of 99 over ...160 cycles, an extremely high capacity compared to any other compound tested against both Li and Na. The reaction mechanism with Na does not simply go through the alloying mechanism observed for Li where the intermediate species are those expected from the phase diagram. In the case of Na, the intermediate phases are mostly amorphous and could not be precisely identified. Surprisingly, we evidenced that a competition takes place at the end of the discharge of the Sb/Na cell between the formation of the hexagonal and the cubic polymorphs of Na3Sb, the last being described in the literature as unstable at atmospheric pressure and only synthesized under high pressure (1–9 GPa). In addition, fluoroethylene carbonate added to the electrolyte combined with an appropriate electrode formulation based on carboxymethyl cellulose, carbon black, and vapor ground carbon fibers seems to be determinant in the excellent performances of this material.
The typical two‐dimensional (2D) semiconductors MoS2, MoSe2, WS2, WSe2 and black phosphorus have garnered tremendous interest for their unique electronic, optical, and chemical properties. However, ...all 2D semiconductors reported thus far feature band gaps that are smaller than 2.0 eV, which has greatly restricted their applications, especially in optoelectronic devices with photoresponse in the blue and UV range. Novel 2D mono‐elemental semiconductors, namely monolayered arsenene and antimonene, with wide band gaps and high stability were now developed based on first‐principles calculations. Interestingly, although As and Sb are typically semimetals in the bulk, they are transformed into indirect semiconductors with band gaps of 2.49 and 2.28 eV when thinned to one atomic layer. Significantly, under small biaxial strain, these materials were transformed from indirect into direct band‐gap semiconductors. Such dramatic changes in the electronic structure could pave the way for transistors with high on/off ratios, optoelectronic devices working under blue or UV light, and mechanical sensors based on new 2D crystals.
Unlike black phosphorus, both arsenic and antimony are typical semimetals in their natural, layered bulk state. However, monolayered arsenene and antimonene are indirect wide‐band‐gap semiconductors, and under strain, they become direct band‐gap semiconductors. Owing to these band‐gap transitions, these materials could find applications in nano‐ and optoelectronic devices.
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