摘要：
Rational design of magnetic materials with desired magnetic properties has attracted wide interest in recent decades. Herein, we present a new 2D cobalt(II) metal-organic framework, namely [Co(MQ)_2(V_2O_6)_2]_n·4 nH_2O 1, which was hydrothermally synthesized by the reaction of Co(NO_3)_2·4H_2O, N-methyl-4,4′-bipyridinium (MQ+) chlorine salt and NH_4VO_3. Single-crystal X-ray diffraction analysis reveals that 1 crystallizes in C2/c space group with a = 16.290(5), b = 7.815(2), c = 25.297(7) A, β = 108.459(5)°, V = 3054.8(15) A~3, Z = 4, D_c = 1.890 g/cm~3, μ = 1.791 mm~(-1), F(000) = 1748, the final R = 0.0444 and wR = 0.1208 with I > 2σ(I). The individual Co(II) is connected and well separated by diamagnetic [V_2O_6]~(2-) linkers. Magnetic measurements confirm that 1 exhibits ferrimagnetic interactions.
期刊：
Physica Status Solidi (C) Current Topics in Solid State Physics,2017年14(3-4):1600110- ISSN：1862-6351
通讯作者：
Huang, Xintang(xthuang@phy.ccnu.edu.cn)
作者机构：
[Wang, Yin] Institute of Nanoscience and Nanotechnology, Central China Normal University, Wuhan, 430079 P.R. China;Corresponding author: e-mail;[Chen, Jinghua] School of Information Management, Central China Normal University, Wuhan, 430079 P.R. China;[Huang, Xintang] Institute of Nanoscience and Nanotechnology, Central China Normal University, Wuhan, 430079 P.R. China<&wdkj&>Corresponding author: e-mail
通讯机构：
[Xintang Huang] I;Institute of Nanoscience and Nanotechnology, Central China Normal University, Wuhan, 430079 P.R. China<&wdkj&>Corresponding author: e-mail
期刊：
Materials Research Express,2017年4(4):045015 ISSN：2053-1591
通讯作者：
Huang, Xin-Tang
作者机构：
[Li, Xiu; Hu, Yan-E; Tan, Jian-Feng; Huang, Xin-Tang] Cent China Normal Univ, Inst Nanosci & Nanotechnol, Dept Phys Sci & Technol, Wuhan 430079, Peoples R China.
通讯机构：
[Huang, Xin-Tang] C;Cent China Normal Univ, Inst Nanosci & Nanotechnol, Dept Phys Sci & Technol, Wuhan 430079, Peoples R China.
关键词：
Fe-doped NiO;gas sensors;nanofoams;porous nanosheets;fast response and recovery;microwave-assisted synthesis
摘要：
Fe-doped NiO, a type of p-type gas sensor, has received wide attention for its low cost, environmentally friendliness and excellent gas-sensing performance. However, the operating temperature of Fe-doped NiO is too high (300 degrees C-500 degrees C). This study attempts to investigate the possibility of Fe-doped NiO working in relatively low temperature regions. A type of NiO nanofoam assembled by porous nanosheets was synthesized through a normal pressure microwave solvent thermal method by a domestic microwave oven, and Fe doping with different doping concentrations was investigated systematically. The gas-sensing performance was tested at a relatively low temperature (200 degrees C-280 degrees C). We found that the Fe-doped NiO still had a good gas-sensing performance, even at a relatively low temperature. In detail, the NiO nanofoams with 3 at% Fe-doping concentration were proven to have the best gas sensing characteristics (the response was 12-100 ppm ethanol at 280 degrees C), and an especially fast response and recovery (the response time and the recovery time was 1 s and 3.6 s, respectively). The study promoted the research regarding the gas sensing characteristics of Fe-doped NiO at a relatively low temperature.
作者机构：
[Pan, Xiaoyang; Yi, Zhiguo; Li, Yunpeng; Chen, Xuxing] Chinese Acad Sci, Key Lab Design & Assembly Funct Nanostruct, Fujian Inst Res Struct Matter, Fuzhou 350002, Peoples R China.;[Pan, Xiaoyang; Yi, Zhiguo; Li, Yunpeng; Chen, Xuxing] Chinese Acad Sci, Fujian Inst Res Struct Matter, Fujian Prov Key Lab Nanomat, Fuzhou 350002, Peoples R China.;[Huang, Xintang; Chen, Xuxing] Cent China Normal Univ, Dept Phys, Inst Nanosci & Nanotechnol, Wuhan 430079, Peoples R China.;[Cortie, David] Australian Natl Univ, Res Sch Chem, Canberra, ACT 2601, Australia.
通讯机构：
[Yi, Zhiguo] C;Chinese Acad Sci, Key Lab Design & Assembly Funct Nanostruct, Fujian Inst Res Struct Matter, Fuzhou 350002, Peoples R China.;Chinese Acad Sci, Fujian Inst Res Struct Matter, Fujian Prov Key Lab Nanomat, Fuzhou 350002, Peoples R China.
摘要：
The search for active catalysts that efficiently oxidize methane under ambient conditions remains a challenging task for both C1 utilization and atmospheric cleansing. Here, we show that when the particle size of zinc oxide is reduced down to the nanoscale, it exhibits high activity for methane oxidation under simulated sunlight illumination, and nano silver decoration further enhances the photo-activity via the surface plasmon resonance. The high quantum yield of 8% at wavelengths < 400 nm and over 0.1% at wavelengths ∼ 470 nm achieved on the silver decorated zinc oxide nanostructures shows great promise for atmospheric methane oxidation. Moreover, the nano-particulate composites can efficiently photo-oxidize other small molecular hydrocarbons such as ethane, propane and ethylene, and in particular, can dehydrogenize methane to generate ethane, ethylene and so on. On the basis of the experimental results, a two-step photocatalytic reaction process is suggested to account for the methane photo-oxidation.
作者机构：
[Shi, JiaMing; Huang, XiaoTian; Qiu, TaoTao] Cent China Normal Univ, Dept Phys Sci & Technol, Wuhan 430079, Peoples R China.;[Qiu, TaoTao] Cent China Normal Univ, Inst Astrophys, Wuhan 430079, Peoples R China.
通讯机构：
[Qiu, TaoTao] C;Cent China Normal Univ, Dept Phys Sci & Technol, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Inst Astrophys, Wuhan 430079, Peoples R China.
关键词：
inflation;vector field;CMB anisotropies
摘要：
Anomalies in recent observational data indicate that there might be some “anisotropic hair” generated in an inflation period. To obtain general information about the effects of this anisotropic hair to inflation models, we studied anisotropic inflation models that involve one vector and one scalar using several types of potentials. We determined the general relationship between the degree of anisotropy and the fraction of the vector and scalar fields, and concluded that the anisotropies behave independently of the potentials. We also generalized our study to the case of multi-directional anisotropies.
摘要：
A facile hydrothermal method was employed to synthesize porous alpha-Fe2O3@SnO2 heterostructure nanotubes. The morphologies and structures of the as-prepared samples were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and N-2 adsorption-desorption techniques. The hollow alpha-Fe2O3 nanotubes with outer diameters of about 90 nm were uniformly coated by a 10 nm thick layer of SnO2 nanoparticles, demonstrating apparent heterostructures. The alpha-Fe2O3@SnO2 heterostructure nanotubes were applied to construct gas-sensor devices which exhibited high sensitivity, fast response-recovery, good selectivity and excellent repeatability to acetone. Because of the porous structure and large specific surface area, the heterogeneous core-shell nanocomposites show a markedly enhanced gas sensing performance in comparison with the initial alpha-Fe2O3 nanotubes and the pure SnO2 nanoparticles. For example, the sensitivity of the alpha-Fe2O3@SnO2 composites to 100 ppm acetone can reach as high as 33.4 at the optimum operating temperature of 300 degrees C, which was about twice of the value for pure alpha-Fe2O3 nanotubes and even up to 5-fold higher than that of pure SnO2 nanoparticles. (C) 2015 Elsevier B.V. All rights reserved.
摘要：
Three cadmium(II) coordination compounds were synthesized via controlling the pH in the in situ [2 + 3] cycloaddition reaction of CdSO4, 4-cyanopyridine, and sodium azide under hydrothermal treatment. Mononuclear 3 was obtained at weak acid solution pH 6.0 similar to 7.0, but 3-D coordination polymers 1 and 2 were preferred in weak alkaline conditions from pH 7.0 to 9.0. Hydrothermal reactions of CdSO4, 4-cyanopyridine, and sodium azide yield three metal coordination compounds via controlling the pH, [Cd-2(4-ptz)(SO4)(OH)(H2O)(2)](H2O) (1) [Cd-2(4-ptz)(SO4)(OH)(H2O)](n) (2), and known [Cd-2(4-ptz)(2)(H2O)(4)](H2O)(2) (3) (4-ptz=5-(4-pyridyl)tetrazole). The in situ [2+3] cycloaddition reaction of nitrile and azide in the presence of Cd(II) produces the multidentate 4-ptz in these compounds. X-ray diffraction results indicate that metal centers in 1 are linked by 4-ptz(-), and OH- in their respective (5)-, (2)-, (3)-bridging modes, forming a 3-D coordination polymer. For 2, although the same raw materials are used, the component anions are linked to Cd(II) centers in completely different ways, i.e. for 4-ptz(-) in (3)-, n (5)-, and OH- in (3)-bridging modes, forming another 3-D coordination network. Thermal stabilities and photoluminescent properties of 1 and 2 have also been investigated.
作者机构：
[Huang, Xintang; Li, Chenjia; Lv, Meng; Zuo, Jialin] Cent China Normal Univ, Dept Phys Sci & Technol, Inst Nanosci & Nanotechnol, Wuhan 430079, Peoples R China.
通讯机构：
[Huang, Xintang] C;Cent China Normal Univ, Dept Phys Sci & Technol, Inst Nanosci & Nanotechnol, Wuhan 430079, Peoples R China.
关键词：
SnO2 nanomaterial;molecular imprinting mechanism;CO gas sensor;high sensitivity
摘要：
Response of highly sensitive SnO<sub>2</sub> semiconductor carbon monoxide (CO) gas sensors based on target gas CO quasi-molecular-imprinting mechanism design is investigated with gas concentrations varied from 50 to 3000 ppm. SnO<sub>2</sub> nanoparticles prepared via hydrothermal method and gas sensor film devices S<sub>C</sub> (exposed to the target gas CO for 12 h after the suspension coating of SnO<sub>2</sub> film to be fully dried, design of quasi-molecular-imprinting mechanism, the experiment group) and S<sub>A</sub> (exposed to air after the suspension coating of SnO<sub>2</sub> film to be fully dried, the comparison group) made from SnO<sub>2</sub> nanoparticles are all characterized by XRD, SEM and BET surface area techniques, respectively. The gas response experimental results reveal that the sensor S<sub>C</sub> demonstrates quicker response and higher sensitivity than the sensor S<sub>A</sub> does. The results suggest that in addition to the transformation of gas sensor materials, surface area, and porous membrane devices, the Molecular Imprinting Theory is proved to be another way to promote the performance of gas sensors. View Full-Text
期刊：
Journal of Alloys and Compounds,2015年633:153-156 ISSN：0925-8388
通讯作者：
Huang, Rui
作者机构：
[Huang, Xintang; Zhang, Yi; Lin, Zhenxu] Cent China Normal Univ, Inst Nanosci & Nanotechnol, Wuhan 430079, Peoples R China.;[Wang, Xiang; Song, Jie; Huang, Rui; Zhang, Yi; Song, Chao; Lin, Zhenxu; Guo, Yanqing] Hanshan Normal Univ, Dept Phys & Elect Engn, Chaozhou 521041, Guangdong, Peoples R China.
通讯机构：
[Huang, Rui] H;Hanshan Normal Univ, Dept Phys & Elect Engn, Chaozhou 521041, Guangdong, Peoples R China.
关键词：
/Plasma enhance chemical vapor deposition;Photoluminescence;Si-based materials;Silicon oxycarbide
摘要：
Luminescent a-SiCxOy films were prepared at a low temperature of 150 °C by using very high frequency plasma enhanced chemical vapor deposition technique. The prepared a-SiCxOy films present remarkable photoluminescence with yellow to blue shifting emission when increasing the oxygen content from 29% to 44%. Interestingly, the light emissions in the visible region can be clearly observed with the naked eyes in a bright room. The structure and the chemical compositions of the films were further investigated by Raman spectroscopy and Fourier transform infrared absorption spectroscopy, respectively. Based on the PL results and the analyses of the bonding configurations of the films, the yellow emission is suggested from the SiC related defect luminescent centers, while the blue emission is associated with Si-related oxygen defect luminescent centers.
期刊：
Sensors and Actuators B-Chemical,2015年212:47-54 ISSN：0925-4005
通讯作者：
Huang, Xintang
作者机构：
[Ruan, Xiaofan; Huang, Xintang; Tan, Wenhu; Yu, Qiuxiang] Cent China Normal Univ, Dept Phys Sci & Technol, Inst Nanosci & Nanotechnol, Wuhan 430079, Peoples R China.
通讯机构：
[Huang, Xintang] C;Cent China Normal Univ, Dept Phys Sci & Technol, Inst Nanosci & Nanotechnol, Wuhan 430079, Peoples R China.
关键词：
SnO2;Quasi molecular-cluster imprinting;Ethanol gas sensor;Clusters
摘要：
A novel method was developed to design highly sensitive ethanol gas sensor based on the mechanism of ethanol quasi molecular imprinting. SnO2 nanoparticles E and W were prepared by incorporating liquid ethanol which is the tested objective gas with deionized water thermal method and pure deionized water thermal method respectively. SnO2 nanoparticle films WW and EW for ethanol gas sensor were obtained by mixing pure deionized water with the as-prepared powders W and E, and WE and EE were prepared by mixing liquid ethanol with W and E powders respectively. The ethanol gas sensing properties of these films were evaluated. Testing results reveal that the sensor S-EE based on film EE which was fabricated by mixing liquid ethanol with E nanoparticles exhibits the most excellent sensing performance to ethanol gas and the response descended in the order of S-WE, S-EW and S-WW. It proves that the introduced objective gas in the procedure of device fabrication plays a very important role for design a highly sensitive gas sensor. In addition, we consider that pore diameter of about 4.3 nm may be the critical size for the smooth adsorption and desorption of ethanol gas. (C) 2015 Elsevier B.V. All rights reserved.
摘要：
The adsorption of methane on intrinsic, vacancy and N-doped graphene are investigated using the first-principles method of density functional theory. We build models by placing methane on three different adsorption sites, including the A, B and C sites above the perfect, vacancy and N-doped graphene. The results indicate that the different adsorption sites of methane on the perfect, vacancy and N-doped graphene have little impact on the band structures. The introduction of N atom can possibly make the adsorption of methane on graphene much easier in the case of A adsorption site. The interactions between methane and N-doped graphenes with a vacancy are much stronger than other systems in the case of B and C adsorption sites.
