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行星式球磨法制备碳—氧化锌纳米复合材料
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作者 尹俊霞 肖坤儒 +2 位作者 堵雷 阮履婕 杨明 《武汉轻工大学学报》 2015年第4期21-23,共3页
以醋酸锌和葡萄糖为原料用行星式球磨法及热解前驱体制备纳米碳—氧化锌复合材料。采用X-射线衍射仪和扫描电子显微镜对产物进行了结构和相貌表征,研究了碳源、热处理温度和时间等因素对纳米碳—氧化锌复合材料的影响。研究表明,以葡萄... 以醋酸锌和葡萄糖为原料用行星式球磨法及热解前驱体制备纳米碳—氧化锌复合材料。采用X-射线衍射仪和扫描电子显微镜对产物进行了结构和相貌表征,研究了碳源、热处理温度和时间等因素对纳米碳—氧化锌复合材料的影响。研究表明,以葡萄糖为碳源,热处理温度为400℃,热处理时间为10 min时,得到的碳—氧化锌复合材料产率为96.8%。 展开更多
关键词 纳米材料 热处理 行星式球磨法 碳—氧化锌
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Enhanced visible-light photocatalytic activity of Z-scheme graphitic carbon nitride/oxygen vacancy-rich zinc oxide hybrid photocatalysts 被引量:16
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作者 刘亚男 王瑞霞 +5 位作者 杨正坤 杜虹 姜一帆 申丛丛 梁况 徐安武 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2015年第12期2135-2144,共10页
With the objectives of enhancing the stability,optical properties and visible-light photocatalytic activity of photocatalysts,we modified oxygen vacancy-rich zinc oxide(Vo-ZnO) with graphitic carbon nitride(g-C3N4... With the objectives of enhancing the stability,optical properties and visible-light photocatalytic activity of photocatalysts,we modified oxygen vacancy-rich zinc oxide(Vo-ZnO) with graphitic carbon nitride(g-C3N4). The resulting g-C3N4/Vo-ZnO hybrid photocatalysts showed higher visible-light photocatalytic activity than pure Vo-ZnO and g-C3N4. The hybrid photocatalyst with a g-C3N4 content of 1 wt% exhibited the highest photocatalytic degradation activity under visible-light irradiation(λ≥ 400 nm). In addition,the g-C3N4/Vo-ZnO photocatalyst was not deactivated after five cycles of methyl orange degradation,indicating that it is stable under light irradiation. Finally,a Z-scheme mechanism for the enhanced photocatalytic activity and stability of the g-C3N4/Vo-ZnO hybrid photocatalyst was proposed. The fast charge separation and transport within the g-C3N4/Vo-ZnO hybrid photocatalyst were attributed as the origins of its enhanced photocatalytic performance. 展开更多
关键词 Oxygen deficient zinc oxide Graphitic carbon nitride Hybrid photocatalysts PHOTODEGRADATION Z-scheme
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Superior activity of Rh1/ZnO single-atom catalyst for CO oxidation 被引量:6
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作者 Bing Han Rui Lang +4 位作者 Hailian Tang Jia Xu Xiang-Kui Gu Botao Qiao Jingyue(Jimmy)Liu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第12期1847-1853,共7页
CO oxidation is of great importance in both fundamental study and industrial application.Supported noble metal catalysts are highly active for CO oxidation but suffer from the scarcity and high cost.Single-atom cataly... CO oxidation is of great importance in both fundamental study and industrial application.Supported noble metal catalysts are highly active for CO oxidation but suffer from the scarcity and high cost.Single-atom catalysts(SACs)can maximize the metal atom efficiency.Herein,ZnO nanowire(ZnO-nw)supported Rh,Au,and Pt SACs were successfully developed to investigate their CO oxidation performance.Interestingly,it was found that Rh1/ZnO-nw showed much higher activity than the other noble metals which are usually regarded as good candidates for CO oxidation.In addition,the Rh SAC possessed high stability in high-temperature CO oxidation under simulated conditions in the presence of water and hydrocarbons.The high activity and stability make Rh1/ZnO-nw promising for practical applications,especially in the automotive exhaust emission control.Theoretical calculations indicate that the CO oxidation proceeds via the Mars-van Krevelen mechanism and the lowest barrier for the rate-limiting O2 dissociation at a surface oxygen vacancy site is a key factor in determining the observed highest activity of Rh1/ZnO-nw amongst the studied SACs. 展开更多
关键词 Single-atom catalysis Carbon monoxide oxidation RHODIUM Zinc oxide nanowire Density functional theory calculations
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Zinc phthalocyanine as an efficient catalyst for halogen-free synthesis of formamides from amines via carbon dioxide hydrosilylation under mild conditions 被引量:3
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作者 Rongchang Luo Xiaowei Lin +2 位作者 Jing Lu Xiantai Zhou Hongbing Ji 《Chinese Journal of Catalysis》 CSCD 北大核心 2017年第8期1382-1389,共8页
The combination of a zinc phthalocyanine(ZnPc)catalyst and a stoichiometric amount of dimethyl formamide(DMF)provided a simple route to formamide derivatives from amines,CO2,and hydrosilanes under mild conditions.We d... The combination of a zinc phthalocyanine(ZnPc)catalyst and a stoichiometric amount of dimethyl formamide(DMF)provided a simple route to formamide derivatives from amines,CO2,and hydrosilanes under mild conditions.We deduced that formation of an active zinc‐hydrogen(Zn‐H)species promoted hydride transfer from the hydrosilane to CO2.The cooperative activation of the Lewis acidic ZnPc by strongly polar DMF,led to formation of activated amines and hydrosilanes,which promoted the chemical reduction of CO2.Consequently,the binary ZnPc/DMF catalytic system showed excellent yields and superior chemoselectivity,representing a simple and sustainable pathway for the reductive transformation of CO2into valuable chemicals as an alternative to conventional halogen‐containing process. 展开更多
关键词 Carbon dioxide Zinc phthalocyanine Cooperative effect N‐formylation HYDROSILANES
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Zinc single atoms on N-doped carbon: An efficient and stable catalyst for CO2 fixation and conversion 被引量:2
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作者 Xinjiang Cui Xingchao Dai +5 位作者 Annette-Enrica Surkus Kathrin Junge Carsten Kreyenschulte Giovanni Agostini Nils Rockstroh Matthias Beller 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第11期1679-1685,共7页
The cycloaddition of epoxides and carbon dioxide represents a straightforward and atom-efficient method for synthesis of cyclic carbonates and utilization of CO2. So far, homogeneous metal complexes have been mainly a... The cycloaddition of epoxides and carbon dioxide represents a straightforward and atom-efficient method for synthesis of cyclic carbonates and utilization of CO2. So far, homogeneous metal complexes have been mainly applied for such transformations. Here, we describe the synthesis of novel heterogeneous Zn-based catalysts, which were conveniently prepared by pyrolysis of an active- carbon-supported phenanthroline-ligated Zn(OAc)2 complex. Detail structural characterizations proved the existence of single zinc sites in the active material. Compared to a Zn-based nanoparticle (Zn-NP) catalyst, the resulting single metal atom catalyst (SAC) displayed improved activity and stability for the cycloaddition of epoxides. By applying the optimal catalyst, a variety of carbonates were successfully obtained in high yields with good functional group tolerance. 展开更多
关键词 Heterogeneous catalysis Single atom catalyst ZINC Carbon dioxide CYCLOADDITION CARBONATE
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ZnCl2 salt facilitated preparation of FeNC: Enhancing the content of active species and their exposure for highly-efficient oxygen reduction reaction 被引量:7
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作者 Zhan Xin Mao Min Jie Wang +5 位作者 Lu Liu Lishan Peng Siguo Chen Li Li Jing Li Zidong Wei 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第5期799-806,共8页
Introducing catalytically-active Fe and N into carbon materials results in promising FeNC catalysts for oxygen reduction reaction. However, the doped Fe and N species are frequently subject to heavy loss in a traditio... Introducing catalytically-active Fe and N into carbon materials results in promising FeNC catalysts for oxygen reduction reaction. However, the doped Fe and N species are frequently subject to heavy loss in a traditional carbonization process owing to Fe agglomeration and evaporation of N-contained small molecules. Besides, pyrolysis may make materials sintering which embeds a large number of active sites in the bulk phase and impedes direct exposure of reactive centers to the reactants. We here report that when calcinations, the addition of ZnCl2, an ordinary salt with very wide melting temperature range well covering the carbonization process of the precursor iron porphyrin, can significantly enhance the doping level of the active species and simultaneously create highly porous structures for FeNC catalysts. The obtained FeNC demonstrates ultrahigh catalytic activities even significantly better than Pt/C in oxygen reduction reaction. 展开更多
关键词 FeNC Catalyst ZNCL2 Porous carbon Oxygen reduction reaction Fuel cell
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Isothermal reduction kinetics of zinc calcine under carbon monoxide 被引量:1
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作者 Yu-jie CHEN Yun-yan WANG +2 位作者 Ning PENG Yan-jie LIANG Bing PENG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第8期2274-2282,共9页
The reduction kinetics of zinc calcine under a CO atmosphere was evaluated by isothermal reductive roasting in a temperature range of 600-800℃.The extent of reaction of zinc calcine was measured using thermogravimetr... The reduction kinetics of zinc calcine under a CO atmosphere was evaluated by isothermal reductive roasting in a temperature range of 600-800℃.The extent of reaction of zinc calcine was measured using thermogravimetry(TG),and the decomposition mechanism of zinc ferrite in zinc calcine was analyzed based on variations in the soluble zinc and ferrous contents.The results indicate that the reaction was controlled by the nucleation of the products,with an apparent activation energy of 65.28 k J/mol.The partial pressure of CO affected the reaction rate more strongly than the CO intensity(defined as PCO/(PCO+PCO2)).The generation rate of zinc oxide was higher than that of ferrous oxide;therefore,the nucleation of ferrous oxide is the rate-determining step of the reaction. 展开更多
关键词 reduction kinetics zinc calcine zinc ferrite carbon monoxide
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Chemical fixation of carbon dioxide to cyclic carbonates catalyzed by zinc(Ⅱ) complex bearing 1,2-disubstituted benzimidazole ligand
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作者 Jorge L. S. Milani Igor S. Oliveira +4 位作者 Pamella A. Dos Santos Ana K. S. M. Valdo Felipe T. Martins Danielle Cangussu Rafael P.Das Chagas 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第2期245-249,共5页
A new zinc(II)complex of formula[ZnCl2(L1)2](1)[L1=2‐(2‐thienyl)‐1‐(2‐thienylmethyl)‐1Hbenzimidazole]was synthesized and fully characterized by nuclear magnetic resonance and infrared spectroscopy,elemental anal... A new zinc(II)complex of formula[ZnCl2(L1)2](1)[L1=2‐(2‐thienyl)‐1‐(2‐thienylmethyl)‐1Hbenzimidazole]was synthesized and fully characterized by nuclear magnetic resonance and infrared spectroscopy,elemental analysis,electrospray ionization high‐resolution mass spectrometry,and thermogravimetric analysis.The molecular structure was confirmed by single‐crystal X‐ray diffraction.Complex1consists of mononuclear tetrahedral zinc(II)units with a locked geometry resulting from weak intramolecular S···?and?–?interligand interactions.The benzimidazole ligand and its zinc(II)complex were readily obtained through a simple synthetic route.The catalytic activity of1was investigated in the coupling of carbon dioxide with epoxides to produce cyclic carbonates,and a series of parameters were evaluated.The complex efficiently catalyzed the transformation of various epoxides under solvent‐free conditions,with good conversions,turnover numbers,and turnover frequencies. 展开更多
关键词 Carbon dioxide Cyclic carbonate Zinc complex Benzimidazole ligand CYCLOADDITION Homogeneous catalysis
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Dip-coating of SiO2 onto ZnO-SiC Composite Membrane
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作者 Hyeyoun Hwang Hyunji Choi Miewon Jung 《Journal of Energy and Power Engineering》 2015年第6期562-565,共4页
SiC composite membrane was fabricated by mixing with SiC and ZnO powder. This mixture was pressed and sintered at 1,300 ℃ under air condition. This sintered ZnO-SiC membrane was dip-coated by silica sol and followed ... SiC composite membrane was fabricated by mixing with SiC and ZnO powder. This mixture was pressed and sintered at 1,300 ℃ under air condition. This sintered ZnO-SiC membrane was dip-coated by silica sol and followed by heat-treatment. This membrane was characterized by XRD (X-ray diffraction), FE-SEM (field emission scanning electron microscopy) and BET (Brunauer-Emmett-Teller) instruments. Hydrogen permeation test was conducted at 0.1 MPa pressure and also variation of temperatures. The obtained value of heat-treated membrane after dip-coating at 298 K was obtained as 1.61 × 10-6 mol/(m2·s·Pa). 展开更多
关键词 ZnO-SiC membrane dip-coated hydrogen permeation test.
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Decorating multiwalled carbon nanotubes with zinc oxide nano-crystallines through hydrothermal growth process 被引量:1
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作者 LI ChenSha QIAO YingJie LI YuMing 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第5期1365-1370,共6页
Multiwalled-carbon nanotubes coated with nano-crystalline zinc oxide (ZnO) was prepared by in situ growth of nano zinc oxide on the surfaces of carbon nanotubes through hydrothermal method. X-ray diffraction, transm... Multiwalled-carbon nanotubes coated with nano-crystalline zinc oxide (ZnO) was prepared by in situ growth of nano zinc oxide on the surfaces of carbon nanotubes through hydrothermal method. X-ray diffraction, transmission electron microscopy and scanning electron microscopy analysis techniques were used to characterize the samples. It was observed that a layer of nano-crystalline ZnO with the wurtzite hexagonal crystal structure was uniformly coated on the nanotube surfaces with good adhesion, which resulted in the formation of a novel ZnO-nanotuhe nano composite. In this work, the carbon nanotubes decorated by metal oxide nanoparticles were synthesized by a simple chemical-solution route which is suitable for the large-scale production with low cost. 展开更多
关键词 carbon nanotubes transmission electron microscopy zinc oxide hydrothermal growth
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A Theoretical Study of a Single-Walled ZnO Nanotube as a Sensor for H_2 O Molecules
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作者 段满益 石国升 +3 位作者 王春雷 周丽萍 陈向荣 方海平 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第8期275-279,共5页
We have studied the property of single-walled ZnO nanotubes with adsorbed water molecules, and theo- retically designed a new sensor for detecting water molecules using single-waJ1ed ZnO nanotubes using a combination ... We have studied the property of single-walled ZnO nanotubes with adsorbed water molecules, and theo- retically designed a new sensor for detecting water molecules using single-waJ1ed ZnO nanotubes using a combination of density functional theory and the non-equilibrium Green's function method. Details of the geometric structures and adsorption energies of the H2O molecules on the ZnO nanotube surface have been investigated, Our computational results demonstrate that the formation of hydrogen bonding between the H2O molecules and the ZnO nanotube, and adsorption energies of the H2O molecules on the ZnO nanotube are larger than the adsorption energies of other gas molecules present in the atmospheric environment. Moreover, the current-voltage curves of the ZnO nanotube with and without H2O molecules adsorbed on its surface are calculated, the results of which showed that the H2O molecules form stable adsorption configurations that could lead to the decrease in current. These results suggest that the single-walled ZnO nanotubes are able to detect and monitor the presence of H2O molecules by applying bias voltages. 展开更多
关键词 ZnO nanotube H20 molecule sensor density functional theory electron transport
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Visible photoluminescence from ZnO/diamond-like carbon thin films 被引量:3
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作者 张立春 李清山 +1 位作者 董艳锋 马自侠 《Optoelectronics Letters》 EI 2012年第2期113-116,共4页
ZnO/diamond-like carbon (DLC) thin films are deposited by pulsed laser deposition (PLD) on Si (111) wafer. Visible room-temperature photoluminescence (PL) is observed from ZnO/DLC thin films by fluorescence spectropho... ZnO/diamond-like carbon (DLC) thin films are deposited by pulsed laser deposition (PLD) on Si (111) wafer. Visible room-temperature photoluminescence (PL) is observed from ZnO/DLC thin films by fluorescence spectrophotometer. The Gaussian curve fitting of PL spectra reveals that the broadband visible emission contains three components with λ=508 nm, 554 nm and 698 nm. The origin and possible mechanism of the visible PL are discussed, and they can be attributed to the PL recombination of ZnO and DLC thin films. 展开更多
关键词 Pulsed laser deposition Silicon wafers Zinc oxide
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