Qiaojuan Gong

An environmentally friendly method for the fabrication of reduced graphene oxide foam with a super oil absorption capacity

Three kinds of graphene oxide (GO) foams were fabricated using different freezing methods (unidirectional freezing drying (UDF), non-directional freezing drying, and air freezing drying), and the corresponding reduced graphene oxide (RGO) foams were prepared by their thermal reduction of those GO foams. These RGO foams were characterized by Fourier transform infrared spectroscopy, thermal gravimetric analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. The absorption process and the factors that influence the absorption capacity were investigated. The RGO foams are hydrophobic and showed extremely high absorbing abilities for organic liquids. The absorption capacity of the RGO foams made by UDF was higher than 100 g g(-1) for all the oils tested (gasoline, diesel oil, pump oil, lubricating oil and olive oil) and had the highest value of about 122 g g(-1) for olive oil. The oil absorption capacity of the GO foams was lower than that of the RGO foams, but for olive oil, the absorption capacity was still high than 70 g g(-1), which is higher than that of most oil absorbents.

Carbon-encapsulated tungsten oxide nanowires as a stable and high-rate anode material for flexible asymmetric supercapacitors

Herein, we report an effective carbon encapsulation strategy to boost the capacitive performance of WO3−x nanowires as a high-energy and stable anode material for flexible asymmetric supercapacitors (ASCs). The carbon-encapsulated WO3−x nanowires exhibited a remarkable areal capacitance of 786.8 mF cm−2 and excellent durability. Furthermore, an ASC device with high energy and power density was also fabricated from the as-prepared carbon encapsulated WO3−x nanowire anode.

Electrochemical Preparation and Characterizations of Hierarchically Polycrystalline NiPb Dendrites

Perfect polycrystalline NiPb dendrites were prepared via cathodic electrochemical deposition on Cu substrates from aqueous solution. Cyclic voltammetry was used to gain insight into the Ni/Pb codeposition mechanism. The results reveal that the dendrite consists of a long central backbone and very orderly secondary and tertiary branches. The size and shape of the dendritic structures can be tunable by changing the synthetic parameters. A formation mechanism is proposed to illustrate the growth process.

Synthesis and crystal structure of α,β-unsaturated ketone: 3,3′-[1,2-ethanediylbis(oxy-2,1-phenylene)]bis[1-(2-pyridyl)-2-propen-1-one]

The title compound, C30H24N2O4, 3,3′-[1,2-ethanediyl-bis(oxy-2,1-phenylene)]bis[1-(2-pyridyl)-2-propen-1-one] was synthesized and characterized by elemental analysis, FT-IR spectra, 1H NMR, and X-ray single-crystal diffraction. In the molecule, the pyridine plane and the adjacent phenyl plane are almost coplanar with the dihedral angle of 3.07°, while the dihedral angle between the mean planes of the two asymmetric units is 67.56°. The crystal packing is stabilized by weak intermolecular C-H...N and C-H...O hydrogen bonds, C-H...π and π...π stacking interactions.

Synthesis, crystal structure and magnetic properties of a two-dimensional cyanide-based heterometallic coordination polymer with cationic piperazinium ligands: poly[aqua­tetra-μ2-cyanido-κ8C:N-dicyan­ido-κ2C-(piperazinium-κN4)cobalt(III)copper(II)]

Cyanide as a bridge can be used to construct homo- and heterometallic complexes with intriguing structures and interesting magnetic properties. These ligands can generate diverse structures, including clusters, one-dimensional chains, two-dimensional layers and three-dimensional frameworks. The title cyanide-bridged Cu(II)-Co(III) heterometallic compound, [Cu(II)Co(III)(CN)6(C4H11N2)(H2O)]n, has been synthesized and characterized by single-crystal X-ray diffraction analysis, magnetic measurement, thermal study, vibrational spectroscopy (FT-IR) and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM-EDS). The crystal structure analysis revealed that it has a two-dimensional grid-like structure built up of [Cu(Hpip)(H2O)](3+) cations (Hpip is piperazinium) and [Co(CN)6](3-) anions that are linked through bridging cyanide ligands. The overall three-dimensional supramolecular network is expanded by a combination of interlayer O-H...N and N-H...O hydrogen bonds involving the coordinated water molecules and the N atoms of the nonbridging cyanide groups and monodentate cationic piperazinium ligands. A magnetic investigation shows that antiferromagnetic interactions exist in the title compound.

Synthesis, characterization, and crystal structure of two α,β-unsaturated ketones with N-heterocycle

Two α,β-unsaturated ketones: C22H16N2O (1), (E)-3-(4-(1H-benzo[d]imidazol-1-yl)phenyl)-1-phenylprop-2-en-1-one and C19H16N2O2 (2), (E)-3-(4-(1H-pyrazol-1-yl)phenyl)-1-(4-methoxyphenyl)prop-2-en-1-one were synthesized and characterized by X-ray diffraction analyses, EA, 1H NMR-, and IR-spectra. In the crystal structure of 1, molecules are linked through intermolecular hydrogen bonds, C-H⋯π and π⋯π interactions forming a 3-D network, while in the crystal structures of 2, molecules are assembled by the C-H⋯O, C-H⋯N hydrogen bonds and C-H⋯π interactions into an infinite 3-D supramolecular structure. A particularly interesting feature of the packing in the structure of 2, is the extensive contribution of C-H⋯π interactions, involving two hydrogen atoms from each of the methyl groups of the methoxy substituents.