Fa-Qian Liu

Amine-Tethered Adsorbents Based on Three-Dimensional Macroporous Silica for CO2 Capture from Simulated Flue Gas and Air

New covalently tethered CO2 adsorbents are synthesized through the in situ polymerization of N-carboxyanhydride (NCA) of l-alanine from amine-functionalized three-dimensional (3D) interconnected macroporous silica (MPS). The interconnected macropores provide low-resistant pathways for the diffusion of CO2 molecules, while the abundant mesopores ensure the high pore volume. The adsorbents exhibit high molecular weight (of up to 13058 Da), high amine loading (more than 10.98 mmol N g(-1)), fast CO2 capture kinetics (t1/2 < 1 min), high adsorption capacity (of up to 3.86 mmol CO2 g(-1) in simulated flue gas and 2.65 mmol CO2 g(-1) in simulated ambient air under 1 atm of dry CO2), as well as good stability over 120 adsorption-desorption cycles, which allows the overall CO2 capture process to be promising and sustainable.

Synthesis, characterization, and high temperature CO2 capture of new CaO based hollow sphere sorbents

New mesoscopic hollow sphere sorbents composed of CaO/Ca12Al14O33 with tunable cavity size are successfully synthesized using sulfonated polystyrene (PS) as hard template. The monodispersed hollow nanostructure provides the void space that can buffer against the large volume change during the carbonation/calcination cycles. The as-prepared high temperature CO2 sorbents have large specific surface areas, fast adsorption kinetics, significantly improved CO2 adsorption capacity and cyclic reaction stability. This method opens up new opportunities in the development of high performance next-generation high temperature CO2 sorbents.

Covalent grafting of polyethyleneimine on hydroxylated three-dimensional graphene for superior CO2 capture

Covalently tethered CO2 adsorbents are synthesized by acid catalyzed ring-opening polymerization of aziridine on the basal planes of three-dimensional hydroxylated graphene (HG). The resulting materials possess high surface areas, strong covalent bonds between polyethyleneimine (PEI) and graphene, and high thermal conductivity. The HG–PEI nanocomposites exhibit high amine loading (more than 10.03 mmol N g−1), high adsorption capacity (up to 4.13 mmol CO2 g−1 in simulated ambient air under 1 atm of dry CO2) as well as good stability both at low (100 °C) and high desorption temperatures (135 °C), which allows the overall CO2 capture process to be promising and sustainable.

A three-dimensional conducting oxide hollow nanobead photoanode: synthesis, characterization, and applications in dye-sensitized solar cells

It was reported that liquid-electrolyte-based dye-sensitized solar cells (DSSCs) are “majority carrier” devices where the internal electric field is screened off; accordingly, the electrons travel through the TiO2 nanoparticles by diffusion rather than drift, resulting in “sticky” electrons which undergo frequent trapping and detrapping. We report here the drift transport observed in I−/I3− electrolyte-based DSSCs by using a 3-dimensional (3-D) transparent conducting oxide (TCO) such as fluorinated tin oxide (FTO) coated with TiO2 as the photoanode. By re-allocating the charge transport process, the thin TiO2 layer (20–30 nm) covering the entire TCO scaffold leads to a striking reduction in charge transport distance by a factor of 102 to 103. Electrochemical impedance spectroscopy (EIS) study indicates that it is viable to establish a potential gradient in the 3-D TCO scaffold; thus, the electron transport in this 3-D TCO structure exhibits field-driven drift behaviour, which is verified by the linear dependence of electron lifetime on the photovoltage, along with the virtual independence of electron transport resistance with respect to the bias voltage in spite of the use of the liquid I−/I3− electrolyte.

A morphology controllable synthesis of 3D graphene nanostructures and their energy storage applications

A template-assisted and morphology-controllable synthesis of 3D sulfonated graphene (SG) architectures was reported. The morphology can be controlled between a hollow nanobeads structure and macro-porous structure. The assembly mechanisms are investigated with respect to influencing factors including surface charge of the templating beads and pH value of the precursory solutions. The structures of these SG nanostructures are characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In the application of the Li-ion battery, a maximum specific capacity of 865.5 mA h g−1 for the macro-porous SG electrode is achieved at a current density of 100 mA g−1. Furthermore, even after 100 cycles, more than 99.0% of the specific capacity is still maintained. In the application of supercapacitors, a maximum specific capacity of 256.25 F g−1 for the hollow nanobead SG cell is achieved at a current density of 0.5 A g−1 and a satisfactory capacity retention is also obtained even after 1000 cycles.

Synthesis of Ag nanoparticles decorated MnO2/sulfonated graphene composites with 3D macroporous structure for high performance capacitors electrode materials

An effective strategy to improve the conductivity of MnO2-based electrodes is to combine them with some conductive materials, such as metal or carbon-based materials. In this work, Ag nanoparticles decorated MnO2/Sulfonated Graphene composite with 3D macroporous structure (3D Ag–MnO2/SG) was synthesized and their performance as electrode material in supercapacitors was studied. The improved conductivity and the elaborate design of 3D porous structure allowed the 3D Ag–MnO2/SG electrode to possess enhanced electrochemical performance. For example, the electrochemical testing results demonstrated that the 3D Ag–MnO2/SG presents a capacitance of 537 F g−1 at 0.5 A g−1, which is much higher than that of MnO2 (∼172 F g−1). Moreover, the 3D Ag–MnO2/SG electrode delivers a higher capacity retention rate in high current density and smaller charge transfer resistance than that of MnO2, which is contributed by the synergistic effect from the Ag nanoparticles and the 3D porous SG.

Triaqua(benzene-1,2-dicarboxylato-kO)-(1,10-phenanthroline-k(2)N,N ')zinc(II) monohydrate

The structure of the title compound, [Zn(C8H4O4)(C12H8N2)-(H2O)(3)]center dot H2O, displays a distorted octahedral coordination geometry, with two N atoms from the bidentate phenanthroline ligand, three O atoms from three meridional H2O molecules and one O atom from the monodentate phthalate ion.

cis-Dichloridobis(1,10-phenanthroline-κ2N,N′)­cadmium(II) hemihydrate

The title compound, [ CdCl2( C12H8N2)(2)]center dot 0.5H(2)O, crystallizes with two independent complex molecules and one water molecule in the asymmetric unit. The Cd atoms in both independent complexes display a distorted octahedral coordination geometry formed by four N atoms from two phenanthroline ligands and two Cl atoms. In the crystal structure, pi-pi stacking interactions link complexes in two symmetry- independent ladders parallel to the c axis. Intermolecular O-H center dot center dot center dot Cl hydrogen bonds stabilize the crystal packing.

4-(2-fluorobenzylideneamino)-3-(1,2,4-triazol-4-ylmethyl)-1H-1,2,4-triazole-5(4H)-thione

In the title compound, C12H10FN7S, the dihedral angles made by the plane of the thione-substituted triazole ring with the planes of the other triazole ring and the benzene ring are 74.55 (2) and 11.50 (3)degrees, respectively. The structure shows a number of N - H center dot center dot center dot N intermolecular hydrogen-bonding interactions, and weak C - H center dot center dot center dot S intra- and intermolecular interactions.

5,6-Dimethyl-1H-benzimidazol-3-ium nitrate.

The title salt, C9H11N2 +·NO3 −, features a planar cation (r.m.s. for 11 non-H atoms = 0.016 Å). In the crystal, N—H⋯O hydrogen bonds link nitrate and benzimidazole ions into a three-dimensional network.