Mahtab Hejazifar;Saeid Azizian;Hassan Sarikhani;Qiang Li;东元 赵

Journal of Analytical and Applied Pyrolysis

2012-3

SBA-15, a type of mesoporous silica, was prepared using recycled mother liquor. The results showed that ethanol accumulation in the mother liquor with continuous recycling damages the ordered structure of SBA-15 silica. The open heating of the mother liquor above 95 °C for 2 h can effectively remove ethanol, reducing the ethanol content to below 5 %. The P123 (pluronic EO ₂₀PO₇₀EO₂₀ triblock copolymer) and HCl remain in the mother liquor and can thus be utilized in the next preparation. Such treatment allows the mother liquor to be recycled at least five times. In this way, almost no acid or wastewater is discharged. The structures of the synthesized SBA-15 silicas are as well ordered as those from the fresh liquor except for slightly smaller pores and thicker pore walls. Its environmentally friendly character and cost-effectiveness make this method highly suitable for industrial SBA-15 silica production.

Lixia Jia;Mingjuan Song;Xiuqun Ye;Haifang Gu;Chenglong Zou;Guoxing Niu;东元 赵

Asian Journal of Chemistry

2013

Aluminophosphates molecular sieves AlPO₄-5 with novel morphologies of brooms and nano-fibers (∼3.8 μm and 70-200 nm in width, respectively) were hydrothermally synthesized by varying the precursor compositions, and used as templates to prepare hexagonal carbon micro and submicro tubes.

Chunxia Zhao;Yunxia Yang;Wen Chen;Huanting Wang;东元 赵;Paul A. Webley

CrystEngComm

2009

Aluminophosphate-based mesoporous molecular sieves with variable amounts of framework manganese have been synthesized at room temperature using cationic surfactant cetyltrimethylammonium chloride as a structure-directing agent. Powder X-ray diffraction shows that all solid products with a d spacing of about 0.42 nm are structurally similar to silica-based MCM-41 materials. After calcination at 500°C to decompose the surfactant these products still show a single broad diffraction peak with a d spacing of 0.36 nm and high surface area (830-930 m²/g), indicating that the products are relatively thermally stable. Electron probe microanalysis shows that the incorporation of Mn²⁺ causes an increase of the framework P/A1 ratio from about 0.6 for manganese-free samples to about 0.7 for manganese-containing samples; these values are lower than 1.0 for an ideal aluminophosphate framework. This increase in P/A1 ratio may account for the improved thermal stability of aluminophosphate mesoporous molecular sieves upon incorporation of Mn²⁺. Electron spin resonance and electron spin echo spectroscopy reveal that Mn²⁺ in both as-synthesized and calcined products is immobile and inaccessible to adsorbates such as water, ammonia, and pyridine. This suggests that Mn²⁺ is located in the mesoporous aluminophosphate framework. This is confirmed by ³¹P electron spin echo modulation which shows that Mn²⁺ is associated with three phosphorus atoms at a distance of 0.34 nm.

东元 赵;Zhaohua Luan;Larry Kevan

Journal of Physical Chemistry B

1997-8-28

An organic reagent-assisted method has been developed for the synthesis and assembly of copper sulfide, cadmium sulfide and silver sulfide nanocrystallites at low temperature under hydro- or solvothermal conditions. Nanowire-like aggregates (with an average diameter of 120 nm and length of 2 μm) assembled by digenite phase copper sulfide nanoparticles, nanotube-like aggregates (with diameters ranging from 40 to 200 nm and lengths from 400 nm to 4 μm) and nanovesicle-like aggregates (with size ranging from 50 to 180 nm) assembled using djurleite phase copper sulfide nanoparticles have been obtained using triethylenediamine, tramethylethylenediamine and di-n-butylamine as the linking agents, respectively. A cetyltrimethyl-ammonium bromide-assisted solvothermal process with CdCl₂ and thiourea as the reactants and ethylenediamine as the solvent has been proposed to control the length of the CdS nanorods from 300 nm to 4.5 μm and construct novel CdS nanorod-based structures, including polydentate wire-like architectures and polydentate sphere-like architectures composed of dozens of CdS nanorods of 10 nm in width and 100 nm in length. A CH₃(CH₂)₁₁SH-template method has been adopted to realize the synthesis and the simultaneous assembly of silver sulfide nanocrystallites with AgNO₃ and Na₂S as reactants. By changing the reaction temperature and the dodecylthiol concentration, two-dimensional orthogonal and hexagonal-like ordered silver sulfide nanoparticle arrays and quasi-orthogonal silver sulfide nanorod arrays can be obtained. This organic reagent-assisted route is very simple and can be extended to the synthesis and assembly of other semiconductor sulfide nanocrystals.

Qingyi Lu;Feng Gao;东元 赵

Nanotechnology

2002-12

Solutions containing hydroxy-FeAl oligocations (HFA) were prepared by two procedures: (1) treatment of a mixture of FeCl₃ and AlCl₃ with aqueous Na₂CO₃, followed by aging of the product and (2) preliminary preparation and aging of hydroxy-Al₁₃ oligocations followed by reaction of the latter with aqueous FeCl₃. Ion-exchange of Na-montmorillonite with HFA yield pillared clay (designated as FeAl-PILC) with d(001) values of 1.98-1.56 nm and a surface area of 230 m²/g. The pillar structure, thermal stability, surface acidity, and reduction behavior of the pillared clays were determined by ²⁷Al-NMR, XRD, DTA, Mössbauer spectroscopy, Py-IR, TPD, TPR. Fe/Al ratios greatly affect the pillar structure, surface area and thermal stability of FeAl-PILC. The pillar in FeAl-PILC with Fe/Al ratio <0.5 has a Keggin structure, similar to that of Al-PILC, but the pillar structures of FeAl-PILC with Fe/Al ≥0.5 are the ferric tripolymer species similar to those of Fe-PILC. The basal spacings, surface area, and thermal stability are decreased with increasing Fe/Al ratio. There is relatively strong interaction between Fe and Al in the pillars. The interaction is enhanced with decreasing Fe/Al ratio. Reduction of the Fe phase in FeAl-PILC was reduced by the interaction of Fe with Al.

东元 赵;Guojia Wang;Yashu Yang;Xiexian Guo;Qibin Wang;Jiyao Ren

Clays and Clay Minerals

1993-6

We report a general emulsion soft-template method to synthesize porous graphene foams for multi-functional applications, including lithium-oxygen batteries and oil-adsorption. Multiple micro-emulsions and micelles were employed to produce three-dimensional porous graphene with well-tailored inter-architecture for the first time. Detailed mechanism study reveals that specific interfacial interactions, such as π-π interaction, hydrophobic affinity or electrostatic interaction, are vital for the formation of porous graphene materials. When applied as cathode materials in lithium-oxygen batteries, the porous graphene foams exhibited good catalytic activity. Besides, the porous graphene materials also demonstrated the capability for oil adsorption with a high efficiency. This journal is

Xiaodan Huang;Bing Sun;Dawei Su;东元 赵;Guoxiu Wang

Journal of Materials Chemistry A

2014-6-7

A simple and convenient method, free of any template, has been proposed to synthesize hollow Ag₂S semiconductor with a novel network-like microstructure under hydrothermal conditions with AgNO₃, thiourea (Tu) and hydrochloric acid as reagents. The ratio of AgNO₃ to Tu, the reaction temperature and the addition of hydrochloric acid are of importance to the formation of the hollow network-like microstructure.

Qingyi Lu;Feng Gao;东元 赵

Chemical Physics Letters

2002-7-10

Ying Wan;东元 赵

2009-10-21

A new organically templated microporous zirconogermanate, (C ₂H₁₀N₂)H₂O[ZrGe₃O ₉] (denoted as FDZG-3), with a low framework density of 13.6 T/1000 ų, has been solvo/hydrothermally synthesized by using ZrO(NO₃)₂·2H₂O as a zirconium source and triethylenetetramine (TETA) as a structure direct agent. This compound was characterized by means of single-crystal X-ray diffraction analysis, thermogravimetrical analysis, and IR and UV-vis spectra. Its three-dimensional (3D) framework is built up by 1D sinusoidal germanate chains cross-linked by ZrO₆ octahedra, which forms a network containing three- and seven-membered rings (MRs). Four intersecting 7-MR channels can be observed along the b axis, c axis, [110], and [-110] directions, respectively. Charge-balancing (C₂H₁₀N₂)²⁺ and extraframework water molecules are encapsulated within 7-MR channels and form hydrogen bonds with framework oxygen atoms. Crystal data for FDZG-3: M = 533.13, monoclinic, space group Cc (No.9), a = 11.299(3) Å, b = 7.7649(19) Å, c = 13.835(3) Å, β = 104.826(3)°, V = 1173.4(5) ų, Z = 4, R1 = 0.0263, wR2 = 0.0529.

Zhicheng Liu;Linhong Weng;Zhenxia Chen;东元 赵

Inorganic Chemistry

2003-9-22