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磁载光催化剂TiO_2/SiO_2/γ-Fe_2O_3的制备及其催化氧化性能 认领 引用 被引量:6
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作者 包淑娟 张校刚 刘献明 《功能材料》 EI CAS 北大核心 2004年第1期108-110,113,共3页
 采用化学共沉淀法制备磁基体(Fe3O4),煅烧使其转化为γ Fe2O3。溶胶 凝胶法成功得到易于固液分离回收的磁载TiO2光催化剂TiO2/SiO2/γ Fe2O3。用TEM和XRD进行形貌和物相表征。研究了催化剂对可溶性染料Orange Ⅱ的降解性能,并探讨了...  采用化学共沉淀法制备磁基体(Fe3O4),煅烧使其转化为γ Fe2O3。溶胶 凝胶法成功得到易于固液分离回收的磁载TiO2光催化剂TiO2/SiO2/γ Fe2O3。用TEM和XRD进行形貌和物相表征。研究了催化剂对可溶性染料Orange Ⅱ的降解性能,并探讨了煅烧温度、时间对活性的影响。结果表明:最佳煅烧温度为450℃,最佳煅烧时间为30min。这种情况下得到的磁载TiO2光催化剂TiO2/SiO2/γ Fe2O3,在3次循环使用后降解率仍保持在95%以上。 展开更多
关键词 磁载 光催化剂 化学共沉淀法 制备 催化氧化性能 TiO2/SiO2/γ-Fe2O3
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The Preparation and Gas-sensing Property of Nanosize γ-Fe_2O_3/SiO_2 认领 引用 被引量:3
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作者 马丽景 闫涛 +4 位作者 白守礼 黄小葳 宋永吉 陈霭璠 LIU Chung Chium 《Chinese Journal of Chemical Engineering》 SCIE EI CAS 2004年第2期282-285,共4页
Nanostructured γ-Fe2O3/SiO2 complex oxide was prepared by sol-gel method with tetraethoxysilane and iron nitrate as precursors. The particle size distribution, thermal and phase stabilities and gas sensing properties... Nanostructured γ-Fe2O3/SiO2 complex oxide was prepared by sol-gel method with tetraethoxysilane and iron nitrate as precursors. The particle size distribution, thermal and phase stabilities and gas sensing properties were systematically characterized by TEM, granularity distribution, TG-DTA, XRD and gas sensitivity measurements. The particle size is about 10 nm and size distribution is very narrow. The sensitivity of the sensing element to CO, H2, C2H4, C6H6 and the effects of calcination temperature on the sensitivity and conductance of gases were examined. The combination of excellent thermal stability and tunable gas sensing properties through careful control of the preparation and judicious selection of material compositions gives rise to novel nanocomposites, which is attractive for the sensitive and selective detection of reducing gases and some hydrocarbon gases. 展开更多
关键词 nanostructural composites Fe2O3 SiO2 gas-sensing properties
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Preparation and properties of magnetic alumina microspheres with a γ-Fe_2O_3/SiO_2 core and Al_2O_3 shell 认领 引用
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作者 Qingtao Fu Tingting He +2 位作者 Lianqing Yu Yongming Chai Chenguang Liu 《Journal of Natural Gas Chemistry》 CSCD 2011年第1期72-76,共5页
Magnetic alumina composite microspheres with γ-Fe 2 O 3 core/Al 2 O 3 shell structure were prepared by the oil column method. A dense silica layer was deposited on the surface of γ-Fe 2 O 3 particles (denoted as γ... Magnetic alumina composite microspheres with γ-Fe 2 O 3 core/Al 2 O 3 shell structure were prepared by the oil column method. A dense silica layer was deposited on the surface of γ-Fe 2 O 3 particles (denoted as γ-Fe 2 O 3 /SiO 2 ) with a desired thickness to protect the iron oxide core against acidic or high temperature conditions. γ-Fe 2 O 3 /SiO 2 /Al 2 O 3 particles with about 85 wt% Al 2 O 3 were obtained and showed to be suitable for practical applications as a magnetic catalyst or catalyst support due to their magnetic properties and pore structure. The products were characterized with scanning electron microscope (SEM) and transmission electron microscope (TEM), nitrogen adsorption-desorption, and vibrating sample magnetometer (VSM). The specific surface area and pore volume of the γ-Fe 2 O 3 /SiO 2 /Al 2 O 3 composite microspheres calcined at 500 ? C were 200 m 2 /g and 0.77 cm 3 /g, respectively. 展开更多
关键词 γ-Fe 2 O 3 microsphere alumina core-shell sol-gel method
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Preparation,characterization and catalytic behavior of hierachically porous CuO/α-Fe_2O3/SiO2composite material for CO and o-DCB oxidation 认领 引用
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作者 Xiaodong Ma Xi Feng +2 位作者 Xuan He Hongwen Guo Lu Lu 《Journal of Natural Gas Chemistry》 CSCD 2011年第6期618-622,共5页
Hierachically porous(HP)CuO/α-Fe2O3/SiO2 composite material was fabricated by sol-gel method and multi-hydrothermal processes using HP-SiO2 as support.The resulting material was characterized by N2 adsorption-desorpt... Hierachically porous(HP)CuO/α-Fe2O3/SiO2 composite material was fabricated by sol-gel method and multi-hydrothermal processes using HP-SiO2 as support.The resulting material was characterized by N2 adsorption-desorption,X-ray diffraction and scanning electron microscopy.The as-prepared CuO/Fe2O3/HP-SiO2 sample,withα-Fe2O3 and CuO nanocrystals,possessed a co-continuous skeleton,through-macroporous and mesoporous structure.Its catalytic behavior for CO and o-DCB oxidation was investigated.The result showed that CuO/Fe2O3/HP-SiO2 catalyst exhibited high catalytic activity for both CO and o-DCB oxidation,indicating its potential application in combined abatement of CO and chlorinated volatile organic compounds. 展开更多
关键词 CO and o-DCB oxidation hierachically porous CuO/α-Fe2O3/HP-SiO2 monolith
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Solid Phase Synthetic Reaction of Sodium Pyroxene for Na_2CO_3-Fe(OH)_3-H_2SiO_3 System 认领 引用
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作者 WANG Yi-ci ZHANG Jian-liang +1 位作者 WANG Yue-cong LUO Guo-ping 《Journal of Iron and Steel Research International》 SCIE CAS CSCD 2013年第1期21-25,共5页
In order to explore synthetic method of pure sodium pyroxene,the pure chemical reagents of Na2CO3,Fe(OH)3 and H2SiO3were used as raw materials,and the possible solid phase reactions for Na2CO3-Fe(OH)3-H2SiO3system... In order to explore synthetic method of pure sodium pyroxene,the pure chemical reagents of Na2CO3,Fe(OH)3 and H2SiO3were used as raw materials,and the possible solid phase reactions for Na2CO3-Fe(OH)3-H2SiO3system in heating process had been studied by means of differential thermal analysis(DTA)and X-ray diffraction(XRD). The influencing factors of sodium pyroxene(NaFeSi2O6)synthetic reaction,such as sintering temperature and holding time,had also been studied.The results show that sodium pyroxene can be largely synthesized at 737℃;it is helpful for synthesis of sodium pyroxene to increase sintering temperature appropriately,and the best temperature should be controlled at 900℃or so,because it will melt and decompose at temperatures higher than 900℃.In those influencing factors of sodium pyroxene synthesis the most important is temperature.The results will be helpful for providing pure NaFeSi2O6for further research on the formation of SFCA for NaFeSi2O6-KAlSi2O3-CaO-Fe2O3-CaF2 system in the sintering process of Bayan-obo iron ore. 展开更多
关键词 solid phase synthesis sodium pyroxene Naz CO3-Fe(OH)3-H2 SiO3 system
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磁性纳米TiO_2/SiO_2/Fe_3O_4光催化剂的制备及表征 认领 引用 被引量:43
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作者 廖振华 陈建军 +2 位作者 姚可夫 赵方辉 李荣先 《无机材料学报》 SCIE EI CAS 北大核心 2004年第4期749-754,共6页
以纳米Fe3O4磁粉为核心,采用溶胶-凝胶法制备了TiO2/SiO2/Fe3O4复合光催化剂。用XRD、TEM及元素分析对其结构和表面形貌进行了表征。以具有偶氮染料结构的甲基橙水溶液为目标反应物,评价其光催化活性。结果表明,所制TiO2/SiO2/Fe3O4样... 以纳米Fe3O4磁粉为核心,采用溶胶-凝胶法制备了TiO2/SiO2/Fe3O4复合光催化剂。用XRD、TEM及元素分析对其结构和表面形貌进行了表征。以具有偶氮染料结构的甲基橙水溶液为目标反应物,评价其光催化活性。结果表明,所制TiO2/SiO2/Fe3O4样品为双层包覆型结构,SiO2为中间层,最外层是锐钛矿型的TiO2。该复合光催化剂对甲基橙溶液有较高的光催化活性,并具有可利用其磁性回收重用的特点,应用前景广泛。 展开更多
关键词 TiO2/SiO2/Fe3O4 包覆 磁性 光催化
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Fe3+/TiO_2/SiO_2复合纳米微粒的合成及光催化降解NO_2^- 认领 引用 被引量:53
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作者 金华峰 李文戈 +1 位作者 向纪明 唐吉玉 《应用化学》 CAS 北大核心 2001年第8期636-639,共4页
采用溶胶 -凝胶法制备了 Ti O2 / Si O2 和不同浓度 Fe3+掺杂的 Fe3+ / Ti O2 / Si O2 复合纳米粉末 ,并利用XRD、BET、UV-vis等手段研究了 Ti O2 / Si O2 及掺铁形成的 Fe3+ / Ti O2 / Si O2 复合微粒的表面结构形态变化 ,以及对污染物... 采用溶胶 -凝胶法制备了 Ti O2 / Si O2 和不同浓度 Fe3+掺杂的 Fe3+ / Ti O2 / Si O2 复合纳米粉末 ,并利用XRD、BET、UV-vis等手段研究了 Ti O2 / Si O2 及掺铁形成的 Fe3+ / Ti O2 / Si O2 复合微粒的表面结构形态变化 ,以及对污染物 NO- 2 光催化降解的影响 .结果表明 ,Fe3+ / Ti O2 / Si O2 (ω( Fe3+ ) =1 .5 % ,m( Ti)∶ m( Si) =2∶ 1 )具有最佳活性 ,样品呈晶化度较低的锐钛矿结构 .Fe3+ 掺杂导致晶粒的增大 ,稳定性降低 ,大大提高了半导体的光催化活性 ,有利于对低浓度 NO- 2 展开更多
关键词 Fe^3+/TiO2/SiO2 TiO2/SiO2 复合微粒 光降解 NO2- 纳米粉末 催化活性 环境污染物 二氧化钛 二氧化硅 铁掺杂 亚硝酸根
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Hydrogen and syngas production from two-step steam reforming of methane over CeO_2-Fe_2O_3 oxygen carrier 认领 引用 被引量:18
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作者 祝星 王华 +2 位作者 魏永刚 李孔斋 程显名 《Journal of Rare Earths》 SCIE EI CAS 2010年第6期907-913,共7页
Two-step steam reforming of methane (SRM) is a novel chemical looping process towards the production of pure hydrogen and syngas (synthesis gas), consisting of a syngas production step and a water-splitting step. Rene... Two-step steam reforming of methane (SRM) is a novel chemical looping process towards the production of pure hydrogen and syngas (synthesis gas), consisting of a syngas production step and a water-splitting step. Renewable energy can be used to drive this process for hydrogen production, especially solar energy. CeO2-Fe2O3 complex oxide oxygen carrier was prepared by the impregnation method and characterized by means of X-ray diffractometer (XRD), Raman spectroscopy (Raman) and hydrogen programmed reduction (H2-TPR). CH4 temperature programmed and isothermal reactions were adopted to test syngas production reactivity, and water splitting reaction was employed to investigate water-splitting activity. Moreover, two-step SRM performance was evaluated by a successive redox cycle. The results showed that CO-uncontaminated H2 and highly selective syngas (with H2/CO ratio close to 2) could be respectively obtained from two steps, and CeFeO3 formation was found in the first redox cycle and proved to be enhanced by the redox treatment. After 10 successive cycles, obvious CeFeO3 phase was detected, which may be responsible for favorable successive redox cycle performances. 展开更多
关键词 two-step steam reforming of methane CeO2-Fe2O3 oxygen carrier redox cycle hydrogen syngas rare earths
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Al2O3对等离子喷涂Cr2O3/TiO2/Al2O3/SiO2复合陶瓷涂层性能影响研究 认领 引用 被引量:11
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作者 贾碧 潘复生 +4 位作者 陈春江 徐榕 江寒梅 王如转 邸永江 《表面技术》 EI CAS CSCD 北大核心 2020年第8期55-62,共8页
目的研究Al2O3添加量对Cr2O3/TiO2/Al2O3/SiO2四元复合陶瓷涂层性能的影响。方法采用等离子喷涂技术在油气管道X80管线钢基体表面制备出具有不同Al2O3含量的四元复合陶瓷涂层。另外,为探究基体温度对涂层性能的影响,所有涂层均在等离子... 目的研究Al2O3添加量对Cr2O3/TiO2/Al2O3/SiO2四元复合陶瓷涂层性能的影响。方法采用等离子喷涂技术在油气管道X80管线钢基体表面制备出具有不同Al2O3含量的四元复合陶瓷涂层。另外,为探究基体温度对涂层性能的影响,所有涂层均在等离子喷枪预热及室温的两种基体上制备。所制涂层的气孔率、硬度、结合力及电化学腐蚀性能分别采用煮沸称重法、维氏硬度计、划痕仪、电化学工作站进行检测,并用X射线衍射仪(XRD)、扫描电镜(SEM)分析不同Al2O3含量涂层的物相组成和形貌特征,研究Al2O3含量对涂层各性能的影响。结果随着Al2O3含量的增加,Cr2O3/TiO2/Al2O3/SiO2四元复合陶瓷涂层的气孔率呈现先降低后增加的趋势,相对应的四元复合陶瓷涂层的结合力、维氏硬度则先增加后降低。当Al2O3质量分数为60%时,四元复合陶瓷涂层的性能最优,气孔率为3.6%,硬度为824.6HV,结合力为53.8 N。电化学腐蚀测试表明,Al2O3能增强涂层的耐腐蚀性能,Al2O3质量分数为60%时,涂层自腐蚀电位最高,为−0.28 V。另外,在基体预热和不预热条件下,所制涂层性能随Al2O3含量的变化一致,但是基体预热比不预热更有利于涂层性能的提高。结论Al2O3的添加不仅能够有效降低涂层Cr含量,还能显著提升四元复合陶瓷涂层的各项性能,特别是耐腐蚀性。此外,等离子喷涂前对基体进行预热,有利于涂层性能提高。 展开更多
关键词 等离子喷涂 X80管线钢 Cr2O3/TiO2/Al2O3/SiO2 陶瓷涂层 微观组织 耐腐蚀性
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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 认领 引用 被引量:10
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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 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
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CaO-SiO_2-Al_2O_3-Fe_2O_3渣系脱磷行为 认领 引用 被引量:11
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作者 王多刚 李杰 +2 位作者 夏云进 张雷 虞大俊 《钢铁研究学报》 CAS CSCD 北大核心 2016年第7期20-25,共6页
利用Factsage软件计算了Al2O3含量对CaO-SiO2-Al2O3-Fe2O3四元渣系熔点和黏度的影响,并通过实验研究了在1 400℃时,CaO-SiO2-Al2O3-Fe2O3四元渣系对高磷铁水脱磷行为的影响。结果表明:渣中Al2O3的质量分数在3%~6%之间时,随着Al2O3含量... 利用Factsage软件计算了Al2O3含量对CaO-SiO2-Al2O3-Fe2O3四元渣系熔点和黏度的影响,并通过实验研究了在1 400℃时,CaO-SiO2-Al2O3-Fe2O3四元渣系对高磷铁水脱磷行为的影响。结果表明:渣中Al2O3的质量分数在3%~6%之间时,随着Al2O3含量的增加,渣系的熔化温度迅速降低,进一步增加渣中的Al2O3含量,渣系的熔化温度逐渐增加;Al2O3对CaO-SiO2-Al2O3-Fe2O3渣系的黏度影响不大;渣中Al2O3的质量分数在3%~6%之间变化时,渣系脱磷能力变化不是很大,脱磷率维持在91%左右,进一步增加渣系中Al2O3的量,脱磷率逐渐下降;Al2O3对脱磷率产生影响可能是其改变了炉渣中液相所占比例,进而影响磷从铁水中向液相渣的传质过程。 展开更多
关键词 CaO-SiO2-Al2O3-Fe2O3渣系 脱磷 熔化温度 液相
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Photocatalytic activity of TiO_2 supported SiO_2-Al_2O_3 aerogels prepared from industrial fly ash 认领 引用 被引量:9
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作者 王慧龙 齐慧萍 +2 位作者 魏晓娜 刘潇彧 姜文凤 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第11期2025-2033,共9页
A ternary composite of TiO2 and a SiO2-Al2O3 aerogel with good photocatalytic activity was prepared by a simple sol-gel method with TiO2 nanoparticles and SiO2-Al2O3 aerogels derived from industrial fly ash.The struct... A ternary composite of TiO2 and a SiO2-Al2O3 aerogel with good photocatalytic activity was prepared by a simple sol-gel method with TiO2 nanoparticles and SiO2-Al2O3 aerogels derived from industrial fly ash.The structural features of the TiO2/SiO2-Al2O3 aerogel composite were investigated by X-ray powder diffraction,Fourier transform infrared spectroscopy,transmission electron microscopy,gas adsorption measurements and diffuse reflectance UV-visible spectroscopy.The optimal conditions for photocatalytic degradation of 2-sec-butyl-4,6-dinitrophenol(DNBP],included an initial DNBP concentration of 0.167 mmol/L at pH = 4.86 with a catalyst concentration of 6 g/L,under visible light irradiation for 5 h.A plausible mechanism is proposed for the photocatalytic degradation of DNBP.Our composite showed higher photocatalytic activity for DNBP degradation than that of pure TiO2.This indicates that this material can serve as an efficient photocatalyst for degradation of hazardous organic pollutants in wastewater. 展开更多
关键词 Titania SiO2-Al2O3 aerogel Composite photocatalyst Industrial fly ash 2-sec-butyl-4 6-dinitrophenol Wastewater treatment
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One-pot hydrothermal fabrication of α-Fe_2O_3@C nanocomposites for electrochemical energy storage 认领 引用 被引量:10
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作者 Maiyong Zhu Jiarui Kan +4 位作者 Jianmei Pan Wenjie Tong Qi Chen Jiacheng Wang Songjun Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第1期1-8,共8页
A facile hydrothermal method was developed for the preparation of Fe_2O_3@C nanocomposites using FeCl_3·6H_2O as iron source and glucose as carbon source under alkaline condition. The morphology and structure of ... A facile hydrothermal method was developed for the preparation of Fe_2O_3@C nanocomposites using FeCl_3·6H_2O as iron source and glucose as carbon source under alkaline condition. The morphology and structure of the as-prepared product were identified by transmission electron microscopy(TEM), high resolution transmission electron microscopy(HRTEM), field-emission scanning electron microscopy(FESEM),X-ray diffraction(XRD), Raman spectroscopy, Fourier Transform infrared spectroscopy(FTIR), and thermogravimetric analysis(TGA). The as-prepare α-Fe_2O_3@C nanocomposites were employed for supercapacitor electrode material. The synergistic combination of carbon electrical double-layer capacitance and α-Fe_2O_3 pseudo-capacitance established such nanocomposites as versatile platform for high performance supercapacitors. The synthesis method developed here is expected to obtain other metal oxide/carbon composite. 展开更多
关键词 α-Fe2O3 Carbon Hydrothermal Pseudocapacitor
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α-Fe_2O_3、γ-Al_2O_3、SiO_2混合体系的表面配位反应 认领 引用 被引量:8
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作者 刘嘉 张卫民 +3 位作者 黄佩佩 樊佳妮 孙仁贵 孙中溪 《物理化学学报》 SCIE CAS CSCD 北大核心 2011年第1期186-192,共7页
运用自动电位滴定技术分别研究了纳米α-Fe2O3、γ-Al2O3、SiO2单一体系及三组分混合体系中氧化物表面的酸碱性质和对重金属离子Cu2+、Pb2+、Zn2+的吸附行为.依据表面配位理论恒电容模式(CCM),计算了相应的表面酸碱配位常数.结果表明:α... 运用自动电位滴定技术分别研究了纳米α-Fe2O3、γ-Al2O3、SiO2单一体系及三组分混合体系中氧化物表面的酸碱性质和对重金属离子Cu2+、Pb2+、Zn2+的吸附行为.依据表面配位理论恒电容模式(CCM),计算了相应的表面酸碱配位常数.结果表明:α-Fe2O3/γ-Al2O3/SiO2三组分混合体系的表面化学反应并非是单一体系的简单叠加,而是存在着不同矿物表面间复杂的交互作用.三组分表面酸碱反应平衡式和相应的酸碱反应平衡常数分别为:≡XOH2+≡XOH+H+(lgKa1=-4.23),≡XOH≡XO-+H+(lgKa2=-8.41).根据重金属离子Cu2+、Pb2+、Zn2+在α-Fe2O3/γ-Al2O3/SiO2混合体系表面的吸附行为,计算得到Cu2+、Pb2+、Zn2+在混合体系表面配位反应及其平衡常数如下:≡XOH+M2+≡XOM++H+;lgK=-2.20,-1.90,-3.20(M=Cu,Pb,Zn). 展开更多
关键词 Fe2O3 Al2O3 SiO2 混合体系 表面配位 表面酸碱性
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超临界流体干燥法制备TiO_2/Fe_2O_3和TiO_2/Fe_2O_3/SiO_2复合纳米粒子及光催化性能 认领 引用 被引量:19
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作者 张敬畅 李青 曹维良 《复合材料学报》 EI CAS 北大核心 2005年第1期79-84,共6页
 以TiCl4、Fe(NO3)3·9H2O和Na2SiO3 9H2O为原料,采用溶胶凝胶法结合超临界流体干燥法(SCFD)制备了纳米级TiO2/Fe2O3和TiO2/Fe2O3/SiO2复合光催化剂。以光催化降解苯酚对所得催化剂的催化活性进行了评价。结果表明,纳米TiO2/Fe2O3...  以TiCl4、Fe(NO3)3·9H2O和Na2SiO3 9H2O为原料,采用溶胶凝胶法结合超临界流体干燥法(SCFD)制备了纳米级TiO2/Fe2O3和TiO2/Fe2O3/SiO2复合光催化剂。以光催化降解苯酚对所得催化剂的催化活性进行了评价。结果表明,纳米TiO2/Fe2O3复合粒子与单组分TiO2比较,复合粒子光催化活性高于单组分的TiO2,6h苯酚降解率高达95 9%。SiO2的加入可以抑制纳米粒子粒径的长大和晶相的转变,增强TiO2纳米粒子的热稳定性。复合光催化剂中Fe2O3最佳掺入量为0 06%,SiO2最佳掺入量为10%(摩尔分数)。并用XRD、TEM和FTIR等手段进行了表征。TiO2以锐钛矿型形式存在,SiO2以无定性形式存在。比较了不同制备方法制得的TiO2/Fe2O3复合光催化剂,得出超临界干燥法制备的光催化剂具有粒径小、比表面积大、分散性好、光催化活性高等特点。采用超临界流体干燥可直接得锐钛型纳米复合光催化剂。 展开更多
关键词 TiO2/Fe2O3 TiO2/Fe2O3/SiO2 纳米粒子 光催化 超临界流体干燥
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Effects of B_2O_3 and CaF_2 on Melting Temperatures of CaO-SiO_2-Fe_2O_3 System Fluxes 认领 引用 被引量:8
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作者 WANG Hong-ming YANG Li-li +3 位作者 LI Gui-rong ZHU Xiang ZHU Hua ZHAO Yu-tao 《Journal of Iron and Steel Research International》 SCIE CAS CSCD 2013年第6期21-24,共4页
Fluorite is widely employed as fluxing agent in metallurgy flux , which inevitably leads to serious fluorine pollution.B2O3 is employed as fluxing agent of CaO-SiO2-Fe2O3steelmaking fluxes to substitute for CaF2.The e... Fluorite is widely employed as fluxing agent in metallurgy flux , which inevitably leads to serious fluorine pollution.B2O3 is employed as fluxing agent of CaO-SiO2-Fe2O3steelmaking fluxes to substitute for CaF2.The effects of B2O3 and CaF2 on the melting properties of this system were investigated.The melting temperatures of fluxes including softening temperature (Ts), hemispherical temperature (Th), and flow temperature (Tf) were measured using the hemisphere method.The results indicate that the fluxing effect of B2O3is more significant than that of CaF2 .When the addition amount of B2O3 (mass percent) exceeds 6% , the melting temperatures of fluxes including Ts , Th and Tf are decreased lower than 1 300℃.The basicity of fluxes has a significant effect on the melting temperature , and the melting temperatures of the fluxes increase with the increase of fluxes basicity.However , when B2O3 is used as fluxing agent , the melting temperature changes little with the basicity increasing from 2.5 to 5.0. These characteristics are suitable for steelmaking process.Moreover , Fe2O3 has an important fluxing effect on this CaO-based steelmaking fluxes.This indicates that the fluxes system is suitable for steelmaking process. 展开更多
关键词 boron oxide calcium fluoride melting temperature CaO-SiO2-Fe2O3 system steelmaking flux
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V_2O_5-WO_3/TiO_2-SiO_2制备及其选择性催化还原脱硝活性 认领 引用 被引量:17
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作者 黄海凤 曾立 +2 位作者 卢晗锋 周春何 陈银飞 《高校化学工程学报》 EI CAS 北大核心 2009年第5期871-877,共7页
以硫酸氧钛和硅溶胶为原料,通过共沉淀法制备得到高比表面积的TiO2-SiO2复合氧化物(Ti/Si=1:1atom),并以此复合氧化物为载体用浸渍法制备了V2O5-WO3/TiO2-SiO2脱硝催化剂,考察了催化剂脱硝性能。结果表明,TiO2-SiO2复合氧化物载体出现... 以硫酸氧钛和硅溶胶为原料,通过共沉淀法制备得到高比表面积的TiO2-SiO2复合氧化物(Ti/Si=1:1atom),并以此复合氧化物为载体用浸渍法制备了V2O5-WO3/TiO2-SiO2脱硝催化剂,考察了催化剂脱硝性能。结果表明,TiO2-SiO2复合氧化物载体出现较多的隧道孔,提高了载体的比表面积,同时Ti元素更易分布在复合氧化物的表面。相比较于纯TiO2,以复合氧化物为载体的V2O5-WO3催化剂表现出更好的活性温度窗口,催化剂表面酸性更强,催化剂对NH3的吸附性能更好,在低的NH3/NO摩尔比情况下(0.8~1.0mol?mol?1),仍然具有较好的脱硝活性,反应温度280~350℃时,脱硝率可达到98%。 展开更多
关键词 脱硝 V2O5-WO3/TiO2-SiO2催化剂 选择性催化还原
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γ-Fe2O3纳米粒表面油酸的测定及对T1造影的影响 认领 引用
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作者 杨政 邓朗 +2 位作者 张彦 熊迎新 陈华黎 《医学诊断》 2025年第1期67-76,共10页
目的:检测γ-Fe2O3纳米粒表面油酸的残留量,考察油酸残留量对纳米粒磁共振T1造影效果的影响。方法:采用热分解法制备γ-Fe2O3纳米粒,使用mPEG-P取代γ-Fe2O3纳米粒表面的油酸,得到水溶性的γ-Fe2O3-PEG纳米粒,采用高效液相色谱法测定纳... 目的:检测γ-Fe2O3纳米粒表面油酸的残留量,考察油酸残留量对纳米粒磁共振T1造影效果的影响。方法:采用热分解法制备γ-Fe2O3纳米粒,使用mPEG-P取代γ-Fe2O3纳米粒表面的油酸,得到水溶性的γ-Fe2O3-PEG纳米粒,采用高效液相色谱法测定纳米粒表面残留的油酸,并在7T磁共振成像仪下考察油酸残留量与纳米粒T1造影效果的关联。最后,对体外造影效果最优的样品进行了体内磁共振成像测试。结果:建立了油酸的高效液相色谱检测方法,油酸在10~400 μg/mL浓度范围内具有良好的线性关系(r2 = 1),平均回收率为99.86%。通过改变γ-Fe2O3与mPEG-P的投料比,得到γ-Fe2O3-PEG纳米粒表面油酸残留个数分别为100、83、56、33的样品。体外磁共振成像结果表明,油酸残留量较少的纳米粒拥有更好的T1加权成像性能。小鼠体内血管造影显示,本研究制备的γ-Fe2O3-PEG纳米粒与临床使用的钆类造影剂相比,拥有更好的血管成像效果。结论:本研究成果为热分解法制备的氧化铁纳米粒表面油酸的定量分析提供了一种有效的检测方法,以促进该类纳米粒在生物医学领域的应用。Objective: Detection of residual oleic acid on the surface of γ-Fe2O3 nanoparticles and investigation of its impact on magnetic resonance T1 imaging. Method: We prepared γ-Fe2O3 nanoparticles via thermal decomposition, with mPEG-P replacing the oleic acid on the surface of the nanoparticles to yield water-soluble γ-Fe2O3-PEG nanoparticles. The residual oleic acid on the surface of the nanoparticles was quantified using High-Performance Liquid Chromatography, and the relationship between the amount of residual oleic acid and the T1 contrast effect of the nanoparticles was investigated using a 7T magnetic resonance imaging system. Finally, the vivo magnetic resonance imaging of the sample exhibiting the optimal in vitro contrast effect was conducted. Results: We developed a High-Performance Liquid Chromatography method for the detection of oleic acid, demonstrating a strong linear correlation in the concentration range of 10~400 μg/mL (r² = 1) with an average recovery rate of 99.86%. By varying the ratio of γ-Fe2O3 to mPEG-P, samples with oleic acid on the surface of γ-Fe2O3-PEG nanoparticles were obtained, with respective counts of 100, 83, 56, and 33. In vitro magnetic resonance imaging demonstrated that nanoparticles with lower residual oleic acid exhibited enhanced T1-weighted imaging performance. In vivo vascular imaging in mice demonstrated that the γ-Fe2O3-PEG nanoparticles prepared in this study provided better imaging results compared to commercially available gadolinium-based contrast agents. Conclusions: This study presents an effective detection method for the quantitative analysis of oleic acid on the surface of iron oxide nanoparticles synthesized via a thermolytic approach, thereby facilitating the application of such nanoparticles in the biomedical field. 展开更多
关键词 γ-Fe2O3 油酸 高效液相色谱法 磁共振成像
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Preparation and characterization of silicone-oil-based γ-Fe2O3 magnetic fluid 认领 引用 被引量:6
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作者 Hang Zheng Hui-Ping Shao +2 位作者 Tao Lin Zi-Fen Zhao Zhi-Meng Guo 《Rare Metals》 SCIE EI CAS CSCD 2018年第9期803-807,共5页
In this study, silicone-oil-based γ-Fe2O3 mag- netic fluid was successfully prepared by thermal oxidizing of Fe3O4 magnetic nanoparticles, which were prepared by chemical co-precipitation with FeSO4-7H2O and FeCl3- 6... In this study, silicone-oil-based γ-Fe2O3 mag- netic fluid was successfully prepared by thermal oxidizing of Fe3O4 magnetic nanoparticles, which were prepared by chemical co-precipitation with FeSO4-7H2O and FeCl3- 6H2O, and their surface was modified by oleate ligands. Silicone oil was used as carrier liquid and oleic acid was as surfactant for preparing γ-Fe2O3 magnetic fluid. It is found that the Fe3O4 nanoparticles surrounded by oleate ligands are not damaged during the thermal oxidizing. The shape of γ-Fe2O3 magnetic nanoparticles prepared is similar to spherical, and their mean size is about 10-20 nm, which has nothing obvious difference compared with Fe3O4. Thesaturation magnetization of γ-Fe2O3 magnetic fluid pre-pared is 14.25 A.me.kg-1 and that of γ-Fe2O3 nanoparti-cles is 57.56 A.m2.kg-1. The needle of γ-Fe2O3 magneticfluid is much bigger than that of Fe3O4 magnetic fluidunder the same magnetic field, which shows better mag-netic properties. 展开更多
关键词 Fe3O4 magnetic particles γ-Fe2O3 magneticparticles γ-Fe2O3 magnetic fluid Saturation magnetization
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微波反应制备纳米TiO_2-Fe_2O_3复合材料及其光催化性能 认领 引用 被引量:12
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作者 丁士文 李梅 +1 位作者 王利勇 丁宇 《河北大学学报(自然科学版)》 CAS 北大核心 2005年第1期38-42,共5页
以TiCl4,FeCl3为原料,尿素为沉淀剂,采用微波加热,均相沉淀法合成了一系列纳米TiO2-Fe2O3复合材料.XRD分析证明反应前驱体为非晶态,500℃以上转变为锐钛矿结构.TEM形貌观察,粒子基本为球形,平均粒径为20nm.EDS分析证明产品中Ti∶Fe的分... 以TiCl4,FeCl3为原料,尿素为沉淀剂,采用微波加热,均相沉淀法合成了一系列纳米TiO2-Fe2O3复合材料.XRD分析证明反应前驱体为非晶态,500℃以上转变为锐钛矿结构.TEM形貌观察,粒子基本为球形,平均粒径为20nm.EDS分析证明产品中Ti∶Fe的分析测定值与实际的投料值基本一致,并且掺杂均匀性好.光吸收及光催化实验发现Fe的摩尔分数为5%时,光催化效果最好,在日光照射180min后,此TiO2-Fe2O3复合材料对藏蓝染料溶液降解率接近100%. 展开更多
关键词 纳米TiO2-Fe2O3 微波合成 均相沉淀 光催化
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