A superior Na3 V2 (PO4 )3 -based nanocomposite (NVP/C/rGO) has been successfully developed by a facile carbothermal reduction method using one most-common chelator, disodium ethylenediamintetraacetate [Na2 (C10 H16 N2 O8 )], as both sodium and nitrogen-doped carbon sources for the first time. 2D-reduced graphene oxide (rGO) nanosheets are also employed as highly conductive additives to facilitate the electrical conductivity and limit the growth of NVP nanoparticles. When used as the cathode material for sodium-ion batteries, the NVP/C/rGO nanocomposite exhibits the highest discharge capacity, the best high-rate capabilities and prolonged cycling life compared to the pristine NVP and single-carbon-modified NVP/C.
View Article and Find Full Text PDFA new cathode material composed of romanechite-structured Na(0.31)MnO(1.9) nanofibers is developed for sodium-ion batteries for the first time.
View Article and Find Full Text PDFThe mechanism and kinetics of the reactions of CF(3)COOCH(2)CH(3), CF(2)HCOOCH(3), and CF(3)COOCH(3) with Cl and OH radicals are studied using the B3LYP, MP2, BHandHLYP, and M06-2X methods with the 6-311G(d,p) basis set. The study is further refined by using the CCSD(T) and QCISD(T)/6-311++G(d,p) methods. Seven hydrogen-abstraction channels are found.
View Article and Find Full Text PDFReactions of (CF3)2CFOCH3 and (CF3)2CFOCHO with hydroxyl radical and chlorine atom are studied at the B3LYP and BHandHLYP/6-311+G(d,p) levels along with the geometries and frequencies of all stationary points. This study is further refined by CCSD(T) and QCISD(T)/6-311+G(d,p) methods in the minimum energy paths. For the reaction (CF3)2CFOCH3 + OH, two hydrogen abstraction channels are found.
View Article and Find Full Text PDFThe geometrical structures, energetics properties, and aromaticity of C(₃₆-n) Si(n) (n ≤ 18) fullerene-based clusters were studied using density functional theory calculations. The geometries of C(₃₆-n) Si(n) clusters undergo strong structural deformation with the increase of Si substitution. For the most energy favorable structures of C(₃₆-n) Si(n) , the silicon and carbon atoms form two distinct homogeneous segregations.
View Article and Find Full Text PDFStimulated by the preparation and characterization of the isolated pentagon rule (IPR) violating chlorofullerene: C(60)Cl(8) (Nat. Mater. 2008, 7, 790-794), we have performed a systematic investigation on the structural stabilities, electronic and optical properties of the IPR-violating C(60)X(8) (X = H, F, and Cl) fullerene compounds via density functional theory.
View Article and Find Full Text PDFStimulated by the recent isolation and characterization of C₅₆Cl₁₀ chlorofullerene (Tan et al., J Am Chem Soc 2008, 130, 15240), we perform a systematic study on the geometrical structures, thermochemistry, and electronic and optical properties of C₅₆X₁₀ (X = H, F, and Cl) on the basis of density functional theory (DFT). Compared with pristine C₅₆, the equatorial carbon atoms in C₅₆X₁₀ are saturated by X atoms and change to sp³ hybridization to release the large local strains.
View Article and Find Full Text PDFElectronic structures and nonlinear optical properties of two highly deformed halofullerenes C(3v) C(60)F(18) and D(3d) C(60)Cl(30) have been systematically studied by means of density functional theory. The large energy gaps (3.62 and 2.
View Article and Find Full Text PDFThe dual-level direct kinetics method has been used to investigate the multichannel reactions of C(2)H(5)I + Cl. Three hydrogen abstraction channels and one displacement process are found for the title reaction. The calculation indicates that the hydrogen abstraction from -CH(2)- group is the dominant reaction channel, and the displacement process may be negligible because of the high barrier.
View Article and Find Full Text PDFA systematic study on the geometrical structures and electronic properties of C(68)X(4) (X=H, F, and Cl) fullerene compounds has been carried out on the basis of density functional theory. In all classical C(68)X(4) isomers with two adjacent pentagons and one quasifullerene isomer [C(s):C(68)(f)] containing a heptagon in the framework, the C(s):0064 isomers are most favorable in energy. The addition reaction energies of C(68)X(4) (C(s):0064) are high exothermic, and C(68)F(4) is more thermodynamically accessible.
View Article and Find Full Text PDFStimulated by the mass spectroscopic observation of the metallofullerene Ca@C(44), we have performed a systematic investigation to search for the most stable isomer using HF/3-21G approximately LanL2DZ, HF/6-31+G(d), B3LYP/6-31+G(d), and MP2/6-31+G(d)//B3LYP/6-31+G(d) methods. The Ca@C(44) (D(2):53) isomer with eight adjacent pentagons in the fullerene framework is predicted to possess the lowest energy. The thermodynamics stability explorations of Ca@C(44) isomers at different temperatures show that Ca@C(44) (D(2):53) is the most thermodynamically stable in the temperature range of absolute zero to 4000 K.
View Article and Find Full Text PDFA polynuclear zinc compound, [Zn(7)(BTA)(7)(OABDC)(mu(3)-OH)(2)(mu(2)-OH)(2).H(2)O] (1), has been prepared by using benzotriazole (HBTA) and 5-oxyacetatoisophthalic acid (H(3)OABDC) as ligands under hydrothermal conditions. For compound 1, an unprecedented metallophthalocyanine-like "Zn(2)(mu(3)-OH)(2) subset [Zn(4)BTA(4)]" subunit is constructed from eta(3)-BTA ligands and Zn atoms and further linked via mu(2)-OH, outer four-connected Zn atoms, and 5-oxyacetateisophthalic acid to form a novel three-dimensional framework.
View Article and Find Full Text PDFAn investigation of C(36)X(n) (X=F,Cl,Br; n=2,4,6,12) formed from the initial C(36) fullerene with D(6h) symmetry has been performed using the MP2 theory. Their equilibrium structures, reaction energies, strain energies, lowest unoccupied molecular orbital-highest occupied molecular orbital (LUMO-HOMO) gap energies, and aromaticities have been studied. The calculation results showed that those addition reaction were highly exothermic and C(36)X(n) were more stable than C(36).
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