期刊文献+
共找到659篇文章
< 1 2 33 >
每页显示 20 50 100
Highly reliable and selective ethanol sensor based on α-Fe2O3 nanorhombs working in realistic environments 被引量:1
1
作者 Wenjun Yan Xiaomin Zeng +3 位作者 Huan Liu Chunwei Guo Min Ling Houpan Zhou 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第10期483-489,共7页
A highly reliable and selective ethanol gas sensor working in realistic environments based on alpha-Fe2O3(α-Fe2O3)nanorhombs is developed. The sensor is fabricated by integrating α-Fe2O3 nanorhombs onto a low power ... A highly reliable and selective ethanol gas sensor working in realistic environments based on alpha-Fe2O3(α-Fe2O3)nanorhombs is developed. The sensor is fabricated by integrating α-Fe2O3 nanorhombs onto a low power microheater based on micro-electro-mechanical systems(MEMS) technology. The α-Fe2O3 nanorhombs, prepared via a solvothermal method, is characterized by transmission electron microscopy(TEM), Raman spectroscopy, x-ray diffraction(XRD), and x-ray photoelectron spectroscopy(XPS). The sensing performances of the α-Fe2O3 sensor to various toxic gases are investigated. The optimum sensing temperature is found to be about 280℃. The sensor shows excellent selectivity to ethanol.For various ethanol concentrations(1 ppm-20 ppm), the response and recovery times are around 3 s and 15 s at the working temperature of 280℃, respectively. Specifically, the α-Fe2O3 sensor exhibits a response shift less than 6% to ethanol at280℃ when the relative humidity(RH) increases from 30% to 70%. The good tolerance to humidity variation makes the sensor suitable for reliable applications in Internet of Things(IoT) in realistic environments. In addition, the sensor shows great long-term repeatability and stability towards ethanol. A possible gas sensing mechanism is proposed. 展开更多
关键词 α-fe2o3 ETHANoL sensor chemi-resistive in REALISTIC environment micro-electro-mechanical systems(MEMS)
下载PDF
纳米α-Fe_2O_3/H_2O_2异相Fenton催化降解酸性橙7 被引量:6
2
作者 龚斌 银玉容 +4 位作者 何其 龙冉冉 王文霞 肖凯军 张玲 《精细化工》 EI CAS CSCD 北大核心 2016年第7期825-831,共7页
以水热法制备纳米α-Fe_2O_3,并应用于异相Fenton体系中催化降解酸性橙7。用扫描电子显微镜(SEM)、X射线衍射仪(XRD)表征样品的结构;在异相Fenton催化体系中,通过优化初始p H、初始底物浓度、双氧水添加量、α-Fe_2O_3添加量、温度,探... 以水热法制备纳米α-Fe_2O_3,并应用于异相Fenton体系中催化降解酸性橙7。用扫描电子显微镜(SEM)、X射线衍射仪(XRD)表征样品的结构;在异相Fenton催化体系中,通过优化初始p H、初始底物浓度、双氧水添加量、α-Fe_2O_3添加量、温度,探究合适的催化降解条件,通过多次循环催化对催化剂稳定性进行研究,并通过催化过程中产生的自由基,分析其催化机理。结果表明,α-Fe_2O_3为长约70 nm,宽约20 nm的均匀单一纳米棒。在异相Fenton催化体系中,最佳催化条件为初始p H=3.0,初始底物质量浓度200 mg/L,反应温度为30℃,双氧水的添加量为w(H_2O_2)=1.5%,催化剂α-Fe_2O_3添加量为500 mg/L,在反应120 min时脱色率为98.74%,COD去除率为73%;稳定性良好,铁离子溶出量低于0.8 mg/L,循环实验5次脱色率始终在90%以上;此外,对自由基的研究表明,·OH在本体系降解过程中占主要作用。 展开更多
关键词 α-fe2o3 双氧水 异相Fenton 催化 酸性橙7 水处理技术与环境保护
下载PDF
粉末活性炭-Fe_3O_4磁性材料-H_2O_2类Fenton体系降解亚甲基蓝研究 被引量:5
3
作者 刘军 杜茹男 李亚峰 《水处理技术》 CAS CSCD 北大核心 2017年第8期55-57,62,共4页
采用粉末活性炭(PAC)-Fe_3O_4磁性材料与H_2O_2组成类Fenton体系降解亚甲基蓝模拟废水,并使用X射线衍射仪、扫描电镜表征磁性材料。结果表明,PAC表面负载的铁氧化物为具有磁性的Fe_3O_4,Fe_3O_4近似球形均匀的负载在PAC表面。该类Fento... 采用粉末活性炭(PAC)-Fe_3O_4磁性材料与H_2O_2组成类Fenton体系降解亚甲基蓝模拟废水,并使用X射线衍射仪、扫描电镜表征磁性材料。结果表明,PAC表面负载的铁氧化物为具有磁性的Fe_3O_4,Fe_3O_4近似球形均匀的负载在PAC表面。该类Fenton体系在PAC-Fe_3O_4磁性材料50 mg、H_2O_2投加量为30μL、p H为3、温度为40℃、反应180 min的条件下降解100 m L质量浓度为200 mg/L亚甲基蓝效果最好,亚甲基蓝和COD去除率分别为100%和94.42%。PAC-Fe_3O_4磁性材料-H_2O_2类Fenton体系对亚甲基蓝有良好的降解效果。 展开更多
关键词 粉末活性炭-fe3o4磁性材料 H2o2类Fenton体系 降解 亚甲基蓝
下载PDF
2D/2D step-schemeα-Fe2O3/Bi2WO6 photocatalyst with efficient charge transfer for enhanced photo-Fenton catalytic activity 被引量:9
4
作者 Wenliang Wang Wenli Zhao +2 位作者 Haochun Zhang Xincheng Dou Haifeng Shi 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第1期97-106,共10页
Although the traditional Fenton reaction is considered an effective strategy for solving problems caused by environmental pollution,construction of an efficient photocatalytic system by coordinating the Fenton reactio... Although the traditional Fenton reaction is considered an effective strategy for solving problems caused by environmental pollution,construction of an efficient photocatalytic system by coordinating the Fenton reaction is challenging.In this study,2D/2D step-schemeα-Fe2O3/Bi2WO6(FO/BWO)heterostructure photo-Fenton catalysts were successfully fabricated by a facile hydrothermal method.The as-prepared materials were characterized by XRD,FT-IR,TEM,XPS,UV-vis DRS,PL,I-t,EIS,and BET analyses.Under visible light irradiation,FO/BWO exhibited remarkably high and stable photo-Fenton catalytic activity for the degradation of methyl blue(MB)at low concentrations of H2O2.It was noted that FO/BWO(0.5)displayed a significantly enhanced photo-Fenton catalytic activity,which was 11.06 and 3.29 times those of FO nanosheets and BWO nanosheets,respectively.The notably improved photo-Fenton catalytic activity of FO/BWO was mainly due to the combination of H2O2 and FO under light illumination and the presence of the 2D/2D S-scheme heterostructure,with the large contact surface,abundant active sites,and efficient separation rate of photogenerated carriers playing contributory roles.Additionally,a possible catalytic mechanism for the FO/BWO composite was preliminarily proposed via active species trapping experiments.In summary,this study provided new insights into the synthesis of an effectively heterogeneous 2D/2D S-scheme photo-Fenton catalyst for degradation of organic pollutants in wastewater. 展开更多
关键词 Bi2Wo6 α-fe2o3 S-scheme PHoTo-fentoN 2D photocatalyst
下载PDF
Photocatalytic remediation of γ-HCH contaminated soil induced by α-Fe_2O_3 and TiO_2 被引量:4
5
作者 ZHAOXu QUANXie ZHAOYa-zhi ZHAOHui-min CHENShuo CHENJing-wen 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2004年第6期938-941,共4页
Heterogeneous photocatalytic degradation of γ-HCH on soil surfaces was carried out to evaluate the photocatalytic effectiveness of α-Fe 2O 3 and TiO 2 toward degrading γ-HCH on soil surfaces. After being spiked ... Heterogeneous photocatalytic degradation of γ-HCH on soil surfaces was carried out to evaluate the photocatalytic effectiveness of α-Fe 2O 3 and TiO 2 toward degrading γ-HCH on soil surfaces. After being spiked with γ-HCH, soil samples were loaded with α-Fe 2O 3 or TiO 2 and exposed to UV-light irradiation. Different catalyst loads, 0%, 2%, 5%, 7%, and 10% (wt.)α-Fe 2O 3; 0%, 0.5%, 1%, 2:(wt.)TiO 2, were tested for up to 7 d irradiation. The effects of soil thickness, acidity, and humic substances were also investigated. The obtained results indicated that the γ-HCH photodegradation follows the pseudo-first-order kinetics. The addition of α-Fe 2O 3 or TiO 2 accelerates the photodegradation of γ-HCH, while the photodegradation rate decreases when the content of α-Fe 2O 3 exceeds 7%(wt.). The degradation rate increases with the soil pH value. Humic substances inhibit the photocatalytic degradation of γ-HCH. Pentachlorocyclohexene, tetrachlorocyclohexene, and trichlorobenzene are detected as photodegradation intermediates, which are gradually degraded with the photodegradation evolution. 展开更多
关键词 photocatalytic degradation Γ-HCH soil surfaces α-fe 2o 3 Tio 2
下载PDF
Enhancement of catalytic activity by homo-dispersing S_2O_8^(2–)-Fe_2O_3 nanoparticles on SBA-15 through ultrasonic adsorption 被引量:4
6
作者 Qingyan Chu Jing Chen +6 位作者 Wenhua Hou Haoxuan Yu Ping Wang Rui Liu Guangliang Song Hongjun Zhu Pingping Zhao 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第5期955-963,共9页
Mesoporous superacids S2O82–-Fe2O3/SBA-15(SFS)with active nanoparticles are prepared by ultrasonic adsorption method.This method is adopted to ensure a homo-dispersed nanoparticle active phase,large specific surface ... Mesoporous superacids S2O82–-Fe2O3/SBA-15(SFS)with active nanoparticles are prepared by ultrasonic adsorption method.This method is adopted to ensure a homo-dispersed nanoparticle active phase,large specific surface area and many acidic sites.Compared with bulk S2O82–-Fe2O3,Br?nsted acid catalysts and other reported catalysts,SFS with an Fe2O3 loading of 30%(SFS-30)exhibits an outstanding activity in the probe reaction of alcoholysis of styrene oxide by methanol with 100%yield.Moreover,SFS-30 also shows a more excellent catalytic performance than bulk S2O82–-Fe2O3 towards the alcoholysis of other ROHs(R=C2H5-C4H9).Lewis and Bronsted acid sites on the SFS-30 surfaces are confirmed by pyridine adsorbed infrared spectra.The highly efficient catalytic activity of SFS-30 may be attributed to the synergistic effect from the nano-effect of S2O82–-Fe2O3 nanoparticles and the mesostructure of SBA-15.Finally,SFS-30 shows a good catalytic reusability,providing an 84.1%yield after seven catalytic cycles. 展开更多
关键词 Mesoporous superacid Nanoparticle Nano effect S2o82-fe2o3/SBA-15 Acidic site Ultrasonic adsorption ALCoHoLYSIS
下载PDF
Growth of Carbon Nanocoils by Porous α-Fe2O3/SnO2 Catalyst and Its Buckypaper for High Efficient Adsorption 被引量:3
7
作者 Yongpeng Zhao Jianzhen Wang +7 位作者 Hui Huang Tianze Cong Shuaitao Yang Huan Chen Jiaqi Qin Muhammad Usman Zeng Fan Lujun Pan 《Nano-Micro Letters》 SCIE EI CAS CSCD 2020年第2期137-153,共17页
High-purity(99%)carbon nanocoils(CNCs)have been synthesized by using porousα-Fe2O3/SnO2 catalyst.The yield of CNCs reaches 9,098%after a 6 h growth.This value is much higher than the previously reported data,indicati... High-purity(99%)carbon nanocoils(CNCs)have been synthesized by using porousα-Fe2O3/SnO2 catalyst.The yield of CNCs reaches 9,098%after a 6 h growth.This value is much higher than the previously reported data,indicating that this method is promising to synthesize high-purity CNCs on a large scale.It is considered that an appropriate proportion of Fe and Sn,proper particle size distribution,and a loose-porous aggregate structure of the catalyst are the key points to the high-purity growth of CNCs.Benefiting from the high-purity preparation,a CNC Buckypaper was successfully prepared and the electrical,mechanical,and electrochemical properties were investigated comprehensively.Furthermore,as one of the practical applications,the CNC Buckypaper was successfully utilized as an efficient adsorbent for the removal of methylene blue dye from wastewater with an adsorption efficiency of 90.9%.This study provides a facile and economical route for preparing high-purity CNCs,which is suitable for large-quantity production.Furthermore,the fabrication of macroscopic CNC Buckypaper provides promising alternative of adsorbent or other practical applications. 展开更多
关键词 Carbon nanocoils Porousα-fe2o3/Sno2 CATALYST BUCKYPAPER Methylene blue adsorption
下载PDF
γ-Fe_2O_3:A magnetic separable catalyst for synthesis of 5-substituted 1H-tetrazoles from nitriles and sodium azide 被引量:1
8
作者 Gang Qi Yong Dai 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第9期1029-1032,共4页
An efficient route for the synthesis of 5-substituted 1H-tetrazole via[2+3]cycloaddition of nitriles and sodium azide is reported usingγ-Fe2O3 nanoparticles as a magnetic separable catalyst.Under optimized condition... An efficient route for the synthesis of 5-substituted 1H-tetrazole via[2+3]cycloaddition of nitriles and sodium azide is reported usingγ-Fe2O3 nanoparticles as a magnetic separable catalyst.Under optimized conditions,the moderate to good yields(71-95%) can be obtained.The catalyst can be easily separated by a magnet and reused for several circles. 展开更多
关键词 γ-fe2o3:Magnetic separable catalyst TETRAZoLE [23]Cycloaddition
下载PDF
α-Fe_2O_3/AC催化剂的制备及光Fenton反应降解双酚A
9
作者 刘旭 张西慧 《化工环保》 CAS CSCD 北大核心 2018年第6期704-709,共6页
采用温和的无模板溶液反应合成了α-Fe_2O_3/AC复合催化剂,作为光Fenton降解双酚A反应的催化剂。通过XRD、SEM、FTIR、DRS、BET、XPS等方法对催化剂的形貌和理化特性进行了分析。结果表明:该催化剂晶型良好,为介孔材料,能够有效吸收和... 采用温和的无模板溶液反应合成了α-Fe_2O_3/AC复合催化剂,作为光Fenton降解双酚A反应的催化剂。通过XRD、SEM、FTIR、DRS、BET、XPS等方法对催化剂的形貌和理化特性进行了分析。结果表明:该催化剂晶型良好,为介孔材料,能够有效吸收和利用紫外光和可见光;该催化剂具有较高的催化活性,稳定性良好;在初始双酚A质量浓度为30 mg/L、溶液pH为4、H_2O_2加入量为320 mg/L、反应温度为40℃、催化剂加入量为1.33g/L的条件下,双酚A降解率可达91.4%。 展开更多
关键词 光Fenton反应 α-fe2o3/AC催化剂 双酚A
下载PDF
固相法制备α-Fe_2O_3纳米粒子 被引量:43
10
作者 邱春喜 姜继森 +1 位作者 赵振杰 杨燮龙 《无机材料学报》 SCIE EI CAS CSCD 北大核心 2001年第5期957-960,共4页
用固相反应法合成了纳米α-Fe2O3粒子。采用XRD、TEM、Mossbauer对合成样品进行表征,结果表明此方法合成的粒子为α-Fe2O3.其粒子呈花生型,粒子直径为20~40nm左右.
关键词 固相合成 纳米粒子 α-fe2o3 α-三氧化二铁 纳米材料
下载PDF
纳米α-Fe_2O_3-TiO_2改性海藻酸钠/壳聚糖双极膜制备与表征 被引量:10
11
作者 陈日耀 陈震 +2 位作者 陈晓 郑曦 孙婷 《无机化学学报》 SCIE CAS CSCD 北大核心 2010年第10期1790-1795,共6页
在壳聚糖(CS)阴离子交换膜中添加纳米复合半导体材料α-Fe2O3-TiO2,制备了PVA-SA/α-Fe2O3-TiO2-CS双极膜(PVA:聚乙烯醇;SA:海藻酸钠),并用扫描电镜、热重分析、电子万能试验机和接触角测定仪等对其进行了表征。研究结果表明,添加纳米α... 在壳聚糖(CS)阴离子交换膜中添加纳米复合半导体材料α-Fe2O3-TiO2,制备了PVA-SA/α-Fe2O3-TiO2-CS双极膜(PVA:聚乙烯醇;SA:海藻酸钠),并用扫描电镜、热重分析、电子万能试验机和接触角测定仪等对其进行了表征。研究结果表明,添加纳米α-Fe2O3-TiO2可提高双极膜的亲水性、热稳定性和机械性能。纳米α-Fe2O3-TiO2复合半导体材料较纳米α-Fe2O3或纳米TiO2单一半导体材料具有更强的光催化双极膜中间界面层水解离能力,在高压汞灯照射下能大大降低双极膜的膜阻抗和膜电阻压降(IR降)。 展开更多
关键词 双极膜 光催化 水解离 纳米α-fe2o3 纳米TIo2
下载PDF
纳米ɑ-Fe_2O_3改性聚乙烯醇基蜂蜡复合涂膜材料工艺优化 被引量:12
12
作者 李璨 王佳媚 +4 位作者 龙门 刘瑶 刘桂超 顾凤兰 章建浩 《农业工程学报》 EI CAS CSCD 北大核心 2014年第3期243-250,共8页
为有效的提高聚乙烯醇(polyvinyl alcohol,PVA)的成膜后阻湿性能,该研究采用乳化剂聚甘油酯和单甘酯复配乳化蜂蜡使其与PVA形成稳定的乳液。在PVA基膜材料中添加了蜂蜡及纳米α-Fe2O3,利用单因素试验确定了响应曲面试验的因素水平,从而... 为有效的提高聚乙烯醇(polyvinyl alcohol,PVA)的成膜后阻湿性能,该研究采用乳化剂聚甘油酯和单甘酯复配乳化蜂蜡使其与PVA形成稳定的乳液。在PVA基膜材料中添加了蜂蜡及纳米α-Fe2O3,利用单因素试验确定了响应曲面试验的因素水平,从而使用响应面试验研究了两者之间对成膜透湿率的影响和交互作用。结果表明:随着蜂蜡添加量增加纳米α-Fe2O3添加量临界值降低且有效降低成膜透湿率,所以这2种材料之间存在明显的交互作用(P<0.05)。回归优化的最优组蜂蜡添加量为0.739 g/100mL,纳米α-Fe2O3添加量为0.04 g/100mL时透湿率达到最低点,比对照组膜降低了73.76%(P<0.05)。优化的膜材料具有明显的抑菌效果,在光催化条件下,能使大肠杆菌菌落总数下降1个数量级。 展开更多
关键词 优化 薄膜 纳米α-fe2o3 蜂蜡 PVA 透湿率 光催化抑菌
下载PDF
导电聚苯胺与磁性γ-Fe_2O_3纳米复合物的电磁性能 被引量:14
13
作者 杨青林 翟锦 +4 位作者 宋延林 万梅香 江雷 徐文国 李前树 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2003年第12期2290-2292,共3页
Nanocomposites of PAn-DBSA/γ-Fe 2O 3 with electrical and ferromagnetic behavior(σ= 2.18×10 -3-5.00×10 -5 S/cm, M s=3.7-16.6 m 2·A/kg, H c=8 805.2-9 133.1 A/m) were prepared by a chemical modification-... Nanocomposites of PAn-DBSA/γ-Fe 2O 3 with electrical and ferromagnetic behavior(σ= 2.18×10 -3-5.00×10 -5 S/cm, M s=3.7-16.6 m 2·A/kg, H c=8 805.2-9 133.1 A/m) were prepared by a chemical modification-redoping method in a neutral medium. The products were characterized by TEM, XRD, UV-Vis, four-probe method, and magnetometer. The results indicate that the electrical and magnetic properties of the nanocomposites strongly depend on γ-Fe 2O 3 content. With the increase of γ-Fe 2O 3 content, the electrical conductivity is decreased and saturation magnetization is increased. 展开更多
关键词 导电聚苯胺 Γ-fe2o3 纳米复合物 电磁性能 三氧化二铁 纳米材料
下载PDF
新型燃烧合成方法制备α-Fe_2O_3纳米晶 被引量:17
14
作者 张剑光 张明福 +1 位作者 韩杰才 赫晓东 《材料工程》 EI CAS CSCD 北大核心 2001年第7期40-42,共3页
将聚乙烯醇 (PVA)作为络合剂与硝酸铁反应 ,不调节反应体系的 p H值成功地制备出α- Fe2 O3纳米晶。络合物在 15 0℃反应后的产物灰烬经 X射线分析 ,含有部分α- Fe2 O3和γ- Fe2 O3,产物灰烬经 40 0℃煅烧 1.5 h后得到的是α- Fe2 O3和... 将聚乙烯醇 (PVA)作为络合剂与硝酸铁反应 ,不调节反应体系的 p H值成功地制备出α- Fe2 O3纳米晶。络合物在 15 0℃反应后的产物灰烬经 X射线分析 ,含有部分α- Fe2 O3和γ- Fe2 O3,产物灰烬经 40 0℃煅烧 1.5 h后得到的是α- Fe2 O3和γ- Fe2 O3的混合物 ,X射线衍射和红外光谱分析的结果显示 ,此时有机组分已分解完全。在 45 0℃煅烧1.5 h,γ- Fe2 O3全部转变为α- Fe2 O3,经透射电镜观察晶粒尺寸在 2 5~ 35 nm之间 ,且为球形 ,在 5 0 0℃的温度下煅烧得到的产物晶粒比 45 0℃煅烧产物晶粒稍有长大 ,在 2 5~ 40 展开更多
关键词 α-fe2o3 纳米晶 燃烧合成 α-四氧化三铁 制备
下载PDF
煅烧温度对Mn改性γ-Fe_2O_3催化剂结构及低温SCR脱硝活性的影响 被引量:13
15
作者 张信莉 王栋 +2 位作者 彭建升 路春美 徐丽婷 《燃料化学学报》 EI CAS CSCD 北大核心 2015年第2期243-250,共8页
采用共沉淀法,在不同煅烧温度下制备一系列Mn改性γ-Fe2O3催化剂(Fe0.7M n0.3Oz),研究了煅烧温度对Fe0.7M n0.3Oz催化剂低温SCR脱硝活性的影响,并借助XRD、N2吸附-脱附、EDS及SEM等手段对催化剂进行表征。结果表明,350℃煅烧所得Fe0.7... 采用共沉淀法,在不同煅烧温度下制备一系列Mn改性γ-Fe2O3催化剂(Fe0.7M n0.3Oz),研究了煅烧温度对Fe0.7M n0.3Oz催化剂低温SCR脱硝活性的影响,并借助XRD、N2吸附-脱附、EDS及SEM等手段对催化剂进行表征。结果表明,350℃煅烧所得Fe0.7M n0.3Oz催化剂的低温SCR活性最佳,在70℃时取得92%的NOx转化率,100~200℃可维持100%的NOx转化率,而450℃煅烧所得催化剂的低温SCR活性最低;煅烧温度为350℃时,催化剂具有最大的比表面积和比孔容、发达的孔隙结构及适当结晶度的γ-Fe2O3,而煅烧温度为400或450℃时,催化剂发生烧结且有α-Fe2O3生成,不利于低温SCR反应的进行,因此,Fe0.7M n0.3Oz催化剂的最佳煅烧温度为350℃。 展开更多
关键词 低温选择性催化还原 催化剂 煅烧温度 Γ-fe2o3 Mn
下载PDF
均分散超微细α-Fe_2O_3水溶胶的制备 被引量:23
16
作者 魏雨 刘晓林 郑学忠 《物理化学学报》 SCIE CAS CSCD 北大核心 1996年第6期551-554,共4页
Cubic and ellipsoide ultrafine monodispersed hematite colloidal particles wereprepared by hydrothermal reaction from Fe(OH)3 get in the presence of Sn4+ ions. Thenumbers of nuclei increase with the concentration of ... Cubic and ellipsoide ultrafine monodispersed hematite colloidal particles wereprepared by hydrothermal reaction from Fe(OH)3 get in the presence of Sn4+ ions. Thenumbers of nuclei increase with the concentration of Sn4+ ions. The initial concentrationof Fe(OH)3 gel might approach to 0.5 mol.L- 1. The products were characterized by TEMand XRD. 展开更多
关键词 α-fe2o3 分散粒子 氧化铁 水溶胶
下载PDF
络合物型溶胶 - 凝胶过程研制纳米晶γ-Fe_2O_3磁粉 被引量:20
17
作者 刘静波 王智民 +3 位作者 谷林夫 刘宝珠 毛桂洁 刘遵田 《功能材料》 EI CAS CSCD 北大核心 1998年第2期144-147,156,共5页
本文与传统的柠檬酸盐方法不同,首次直接以柠檬酸铁为起始物质,经由络合物型溶胶凝胶过程非醇盐法制得超细的铁棕磁粉。使用DTA、XRD、FTIR、SEM、BET以及磁天平等测试手段,表征了试样的特性,证明产物为纳米晶... 本文与传统的柠檬酸盐方法不同,首次直接以柠檬酸铁为起始物质,经由络合物型溶胶凝胶过程非醇盐法制得超细的铁棕磁粉。使用DTA、XRD、FTIR、SEM、BET以及磁天平等测试手段,表征了试样的特性,证明产物为纳米晶γFe2O3,具有良好的磁性,XRD给出了原始晶粒的精确尺寸30.4nm,并与BET所测平均团粒尺寸147nm加以比较。讨论了络合物型溶胶凝胶过程的最适宜工艺条件和某些反应机理。 展开更多
关键词 络合物型 溶胶-凝胶过程 纳米晶 Γ-fe2o3
下载PDF
煅烧温度对γ-Fe_2O_3催化剂结构及其脱硝活性的影响 被引量:8
18
作者 王栋 张信莉 +3 位作者 彭建升 路春美 韩奎华 徐丽婷 《环境科学研究》 EI CAS CSSCI CSCD 北大核心 2015年第5期808-815,共8页
采用沉淀-微波热解法,以Fe SO4·7H2O为铁源制备环境友好的γ-Fe2O3催化剂,结合XRD(X射线衍射)、N2等温吸附-脱附、SEM(扫描电子显微镜)、EDS(能谱仪)等手段对催化剂样品的晶相、孔结构、表面形貌、表面元素组成等进行表征,... 采用沉淀-微波热解法,以Fe SO4·7H2O为铁源制备环境友好的γ-Fe2O3催化剂,结合XRD(X射线衍射)、N2等温吸附-脱附、SEM(扫描电子显微镜)、EDS(能谱仪)等手段对催化剂样品的晶相、孔结构、表面形貌、表面元素组成等进行表征,并考察其NH3-SCR(选择性催化还原)脱硝性能,研究煅烧温度对γ-Fe2O3催化剂物性及NH3-SCR脱硝性能的影响规律.结果表明:300、350和450℃下煅烧制备的催化剂中生成的杂质α-Fe2O3对SCR反应不利,而400℃煅烧制备的γ-Fe2O3催化剂脱硝性能最优,NOx转化率最高可达95%以上,XRD结果表明其纯度高,并且在60~100 nm孔径区间具有发达的孔隙结构,有利于SCR反应进行;随着煅烧温度升高,γ-Fe2O3催化剂表面晶格氧逐渐增加,颗粒形貌经历了片状颗粒(300、350℃)→球状颗粒(400℃)→针状颗粒(450℃)的变化过程,均匀的球状颗粒形貌及其表面丰富的晶格氧是400℃煅烧制得催化剂具备最优脱硝性能的重要因素. 展开更多
关键词 选择催化还原 脱硝 催化剂 Γ-fe2o3 煅烧温度 微波
下载PDF
γ-Fe_2O_3纳米粉末的光谱吸收特性研究 被引量:20
19
作者 王泽敏 刘勇 +1 位作者 戢明 曾晓雁 《功能材料》 EI CAS CSCD 北大核心 2006年第2期284-286,291,共4页
利用专门的纳米粉末制备装置,以直径为Φ0.5mm的纯铁丝为原料,采用波长为1064nm的Nd∶YAG脉冲激光器在流动的N2/O2混合反应气体中制备得到了-γFe2O3纳米粉末,采用X射线和光电子能谱仪(XPS)对纳米粉末的结构和表面成分进行了表征。利用... 利用专门的纳米粉末制备装置,以直径为Φ0.5mm的纯铁丝为原料,采用波长为1064nm的Nd∶YAG脉冲激光器在流动的N2/O2混合反应气体中制备得到了-γFe2O3纳米粉末,采用X射线和光电子能谱仪(XPS)对纳米粉末的结构和表面成分进行了表征。利用紫外/可见光分光度计和傅立叶近红外光谱仪,分别测试了平均粒径为20nm的-γFe2O3纳米粉末在紫外/可见光和红外光谱段的吸收性能,同时对光谱吸收机理进行了分析。实验结果表明,与普通的γ-Fe2O3相比,纳米级的-γFe2O3粉末在红外、紫外/可见光波段都有较强的吸收,对应的吸收率都是随着纳米粉末含量的增加而不断提高。 展开更多
关键词 γ-fe2o3纳米粉 紫外/可见光光谱 红外光谱 吸收机理
下载PDF
一种液相制备均匀α-Fe_2O_3微粉的新方法 被引量:9
20
作者 魏雨 赵建路 +1 位作者 武瑞涛 张艳峰 《功能材料》 EI CAS CSCD 北大核心 2000年第1期105-106,共2页
利用沸腾回流强迫水解法由FeCl3或Fe(NO3) 3溶液( 0 .5 -1.0mol·L-1)在弱酸性环境下 ,制备了均匀亚微米级α -Fe2 O3胶粒。如果在反应液中加入微量Na2 SO3,完全转化为α-Fe2 O3粒子的时间可缩短至几小时。
关键词 均匀胶粒 液相制备 α-fe2o3 微粉
下载PDF
上一页 1 2 33 下一页 到第
使用帮助 返回顶部