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91.
Primary thioamides are prepared in moderate to excellent yields by treating nitriles with sodium hydrogen sulfide and diethylamine hydrochloride in an appropriate solvent with mild heating. 相似文献
92.
Ling Zhang Hongqi Wan Lei Chen Huidi Zhou Jianmin Chen 《Journal of Dispersion Science and Technology》2013,34(6):846-850
Sb2S3 nanoparticles surface-modified with S-tetradecyl N, N-dihydroxyethyl dithiocarbamate (C14DTC-Sb2S3) have been synthesized via extraction of Sb2S3 colloidal particles from ethylene glycol into toluene in the presence of C14DTC. The obtained products were characterized by high-resolution transmission electron microscope (HRTEM) and Fourier transformation infrared (FTIR), and their tribological behaviors as an additive in liquid paraffin were investigated using a four-ball tribometer. The results show that C14DTC-Sb2S3 nanoparticles can significantly improve the friction reduction, anti-wear, and load-carrying properties of base oils. The preliminary lubrication mechanism was discussed based on the SEM and XPS investigation of the rubbed surfaces. 相似文献
93.
硫化铟是一种稳定、低毒性的半导体材料. 本文采用低成本的化学浴沉积方法制备了硫化铟敏化太阳电池, X射线衍射(XRD)、光电子能谱(XPS)和扫描电镜(SEM)结果表明形成了硫化铟敏化的二氧化钛薄膜. 化学浴沉积温度对所得硫化铟敏化薄膜的形貌有显著的影响, 进而影响电池性能. 温度太低时, 化学浴沉积反应速率太低, 只发生少量沉积; 温度太高时, 化学浴沉积反应速率较快, 硫化铟来不及沉积到二氧化钛多孔薄膜内部. 当温度在40℃时, 硫化铟沉积均匀性最好, 薄膜的光吸收性能最佳, 电池的短路电流最大, 另外, 填充因子达到最佳, 为65%, 电池总体光电转换效率为0.32%. 相似文献
94.
采用喷雾辅助气相沉积法在水热法合成的ZnO纳米线上沉积CdS纳米颗粒。采用X射线衍射仪(XRD)、激光拉曼仪(Raman)、扫描电镜(SEM)、透射电镜(TEM)、X射线光电子能谱分析谱(XPS)和紫外可见漫反射光谱等测试手段对复合光催化剂进行表征。结果表明,3~10 nm的CdS纳米粒子修饰在直径约为100 nm ZnO纳米线的表面。XPS和Raman表明复合材料中ZnO和CdS之间存在化学相互作用。可见光催化降解罗丹明B实验结果表明ZnO/CdS复合材料的催化性能优于单相CdS或ZnO,沉积时间为30 s合成的ZnO/CdS速率常数分别是CdS和ZnO的2.91和4.03倍,且具有较高的稳定性。ZnO/CdS复合材料光催化性能增强的可能原因为光吸收范围的拓展和光生载流子分离效率的提高。 相似文献
95.
Michelle Chan Alexandra Capek Daniel A. Brill Simon J. Garrett 《Surface and interface analysis : SIA》2014,46(7):433-441
The dark gray corrosion layer (patina) formed on the surface of a polished low tin bronze alloy following exposure to a deoxygenated and saturated aqueous solutions of H2S has been characterized by X‐ray photoelectron spectroscopy, scanning electron microscopy‐energy dispersive spectroscopy and X‐ray diffraction. The system represents a model for bronze corrosion in reducing conditions where sulfate‐reducing bacteria in soils or deoxygenated seawater may generate H2S during respiration. The initial surface was dominated by metallic copper together with Sn, Pb and Zn oxides and hydroxides. Surface enrichment of Pb and Zn was noted because of a smearing effect during polishing. At least some of the lead was crystalline. In contrast, the corrosion layer formed by H2S(aq) exposure was dominated by polycrystalline Cu2S (low and high chalcocite) and smaller concentrations of CuSO4 · nH2O. This surface was enriched with Zn as Zn(OH)2. Lead was present as redeposited PbS (galena) crystallites in at least two different morphologies. Unlike bronzes exposed to oxidizing conditions, which develop protective SnO2 layers, the H2S(aq)‐exposed surface was considerably depleted in Sn. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
96.
Preparation of Yolk‐Shell and Filled Co9S8 Microspheres and Comparison of their Electrochemical Properties 下载免费PDF全文
In this study, we report the first preparation of phase‐pure Co9S8 yolk–shell microspheres in a facile two‐step process and their improved electrochemical properties. Yolk–shell Co3O4 precursor microspheres are initially obtained by spray pyrolysis and are subsequently transformed into Co9S8 yolk–shell microspheres by simple sulfidation in the presence of thiourea as a sulfur source at 350 °C under a reducing atmosphere. For comparison, filled Co9S8 microspheres were also prepared using the same procedure but in the absence of sucrose during the spray pyrolysis. The prepared yolk–shell Co9S8 microspheres exhibited a Brunauer–Emmett–Teller (BET) specific surface area of 18 m2 g?1 with a mean pore size of 16 nm. The yolk–shell Co9S8 microspheres have initial discharge and charge capacities of 1008 and 767 mA h g?1 at a current density of 1000 mA g?1, respectively, while the filled Co9S8 microspheres have initial discharge and charge capacities of 838 and 638 mA h g?1, respectively. After 100 cycles, the discharge capacities of the yolk–shell and filled microspheres are 634 and 434 mA h g?1, respectively, and the corresponding capacity retentions after the first cycle are 82 % and 66 %. 相似文献
97.
o‐Fluorination of Aromatic Azides Yields Improved Azido‐Based Fluorescent Probes for Hydrogen Sulfide: Synthesis,Spectra, and Bioimaging 下载免费PDF全文
Chao Wei Runyu Wang Dr. Lv Wei Longhuai Cheng Zhifei Li Prof. Dr. Zhen Xi Prof. Dr. Long Yi 《化学:亚洲杂志》2014,9(12):3586-3592
Hydrogen sulfide (H2S) is an endogenously produced gaseous signaling molecule with multiple biological functions. To visualize the endogenous in situ production of H2S in real time, new coumarin‐ and boron‐dipyrromethene‐based fluorescent turn‐on probes were developed for fast sensing of H2S in aqueous buffer and in living cells. Introduction of a fluoro group in the ortho position of the aromatic azide can lead to a greater than twofold increase in the rate of reaction with H2S. On the basis of o‐fluorinated aromatic azides, fluorescent probes with high sensitivity and selectivity toward H2S over other biologically relevant species were designed and synthesized. The probes can be used to in situ to visualize exogenous H2S and D ‐cysteine‐dependent endogenously produced H2S in living cells, which makes them promising tools for potential applications in H2S biology. 相似文献
98.
Joseph Israel Gurti Prof. Xun-Lei Ding Ya-Ya Wang Yan Chen Dr. Wei Li Dr. Xin Wang 《Chemphyschem》2022,23(14):e202200124
The reaction of N2 with trinuclear niobium and tungsten sulfide clusters Nb3Sn and W3Sn (n=0–3) was systematically studied by density functional theory calculations with TPSS functional and Def2-TZVP basis sets. Dissociations of N−N bonds on these clusters are all thermodynamically allowed but with different reactivity in kinetics. The reactivity of Nb3Sn is generally higher than that of W3Sn. In the favorite reaction pathways, the adsorbed N2 changes the adsorption sites from one metal atom to the bridge site of two metal atoms, then on the hollow site of three metal atoms, and at that place, the N−N bond dissociates. As the number of ligand S atoms increases, the reactivity of Nb3Sn decreases because of the hindering effect of S atoms, while W3S and W3S2 have the highest reactivity among four W3Sn clusters. The Mayer bond order, bond length, vibrational frequency, and electronic charges of the adsorbed N2 are analyzed along the reaction pathways to show the activation process of the N−N bond in reactions. The charge transfer from the clusters to the N2 antibonding orbitals plays an essential role in N−N bond activation, which is more significant in Nb3Sn than in W3Sn, leading to the higher reactivity of Nb3Sn. The reaction mechanisms found in this work may provide important theoretical guidance for the further rational design of related catalytic systems for nitrogen reduction reactions (NRR). 相似文献
99.
Stanislav S. Stoyko Andrew J. Craig Joshua W. Kotchey Jennifer A. Aitken 《Acta Crystallographica. Section C, Structural Chemistry》2021,77(1):1-10
The new quaternary thiosilicate, Li2PbSiS4 (dilithium lead silicon tetrasulfide), was prepared in an evacuated fused‐silica tube via high‐temperature, solid‐state synthesis at 800 °C, followed by slow cooling. The crystal structure was solved and refined using single‐crystal X‐ray diffraction data. By strict definition, the title compound crystallizes in the stannite structure type; however, this type of structure can also be described as a compressed chalcopyrite‐like structure. The Li+ cation lies on a crystallographic fourfold rotoinversion axis, while the Pb2+ and Si4+ cations reside at the intersection of the fourfold rotoinversion axis with a twofold axis and a mirror plane. The Li+ and Si4+ cations in this structure are tetrahedrally coordinated, while the larger Pb2+ cation adopts a distorted eight‐coordinate dodecahedral coordination. These units join together via corner‐ and edge‐sharing to create a dense, three‐dimensional structure. Powder X‐ray diffraction indicates that the title compound is the major phase of the reaction product. Electronic structure calculations, performed using the full potential linearized augmented plane wave method within density functional theory (DFT), indicate that Li2PbSiS4 is a semiconductor with an indirect bandgap of 2.22 eV, which compares well with the measured optical bandgap of 2.51 eV. The noncentrosymmetric crystal structure and relatively wide bandgap designate this compound to be of interest for IR nonlinear optics. 相似文献
100.
《中国化学快报》2021,32(10):3155-3158
Accurate detection of hydrogen sulfide (H2S) is of great significance for environmental monitoring and protection. We propose a colorimetric method for the detection of H2S by the use of mixed-node Cu-Fe metal organic frameworks (Cu-Fe MOFs) as highly efficient mimic enzymes for target-induced deactivation. The Cu-Fe MOFs were synthesized by a simple solvothermal method and could catalyze the H2O2 mediated oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to oxTMB with a blue color. The presence of dissolved H2S would deactivate the mimic enzymes, and then the blue color disappeared. The mechanism of the sensor was discussed by steady-state kinetic analysis. The designed assay was highly sensitive for H2S detection with a linear range of 0−80 μmol/L and a detection limit of 1.6 μmol/L. Moreover, some potential substances in the water samples had no interference. This method with the advantages of low cost, high sensitivity, selectivity, and visual readout with the naked eye was successfully applied to the determination of H2S in industrial wastewater samples. 相似文献