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Surface nucleation and independent growth of Ce（OH）4 within confinement space on modified carbon black surface to prepare nano-ceo2 without agglomeration

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Frontiers of Materials Science 2018年第2期12卷 168-175页

作者： Xinyue ZHANG Chunhui XIA Kaitao LI Yanjun LIN State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Beijing 100029 China

Highly dispersed negative carboxyl groups can be formed on carbon black （CB） surface modified with strong nitric acid. Therefore positive cations can be uniformly absorbed by carboxyl groups and precipitated within a confinement space on modified CB surface to prepare highly dispersed nanomaterials. In this paper, the formation and dispersion status of surface negative carboxyl groups, adsorption status of Ce^3＋, surface confinement nucleation, crystallization and calcination process were studied by EDS, SEM, and laser particle size analysis. The results show that the carboxyl groups formed on modified CB surface are highly dispersed, and Ce^3＋ cations can be uniformly anchored by carboxyl groups. Therefore, highly dispersed Ce^3＋ can react with OH^- within a confinement surface region to form positive nano-Ce（OH）4 nuclei which also can be adsorbed by electrostatic attraction. After independent growth of Ce（OH）4 without agglomeration, highly dispersed ceo2 nanoparticles without agglomeration can be prepared together with the help of effectively isolates by CO2 released in the combustion of CB.

关键词： surface nucleation confinement space modified CB agglomeration nano-ceo2

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Solvothermal synthesis of nano-ceo_2 aggregates and its application as a high-efficient arsenic adsorbent

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Rare Metals 2019年第1期38卷 73-80页

作者： Jing-Hua Pang Ying Liu Jun Li Xiao-Jiao Yang College of Materials Science and Engineering Sichuan University

Aggregates of cerium dioxide nanoparticles(nano-ceo_2) were successfully prepared via a facile solvothermal process in this study. The crystallographic information and morphological information of nano-ceo_2 were systematically studied by X-ray diffraction(XRD),transmission electron microscopy(TEM), laser particle size analyzer(LA) and specific surface area and pore size analyzer during the solvothermal process. Among all the obtained samples, the 18-h solvothermal-prepared nano-ceo_2 aggregates show the best crystallinity and the largest specific surface area of 110.92 m^2·g^(-1). Owing to the high activity derived from the high specific surface area of the aggregates, the application as arsenic(As) adsorption was also studied. The adsorption efficiency of arsenic by nano-ceo_2 aggregates was established as the function of adsorbent dose, then pH value and at last adsorption *** results indicate that the nano-ceo_2 aggregates show a high efficiency in removing arsenic from low As concentration solution, from which the nano-ceo_2 adsorbent could be easily separated. In addition, the adsorption kinetics is best fitted to pseudo-second-order model(R^2 = 0.99999).

关键词： nano-ceo2 Large surface Aggregates Solvothermal Removal of arsenic

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Microstructure and tensile properties of Mo alloy synthetically strengthened by nano-Y_2O_3 and nano-ceo_2

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Rare Metals 2014年第1期33卷 58-64页

作者： Ren-Zhi Liu Kuai-She Wang Peng-Fa Feng Geng An Qin-Li Yang Hu Zhao Institute of Metallurgy Xi’an University of Architecture and Technology Laboratory of Molybdenum Metal and Its Processing Jinduicheng Moly Co. Ltd State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong University

nano-Y2O3 and nano-ceo2 of different weight ratio mixed with deionizing water were doped into MoO2 powder by liquid-solid doping method. The diameter 1.80 and 0.18 mm alloy wires of Mo-0.3Y, Mo-0.3Ce, and Mo-0.15Y-0.15Ce were prepared through reduction, iso- static pressing, sintering, and drawing. Tensile properties, second phase microstructure and fracture surface appear- ance of wires were analyzed. The better refining effect for Mo alloy powder can be gotten after two kinds of nano- particle oxide doped into MoO2 than only one doped. nano-Y2O3 and nano-ceo2 have different influences on sintering process. For nano-ceo2, the constraining effect of grain growth focuses on the initial sintering stage, nano- Y2O3 plays refining grains roles in the later densification stage. nano-Y2O3 is undistorted and keeps intact in the process of drawing; and nano-ceo2 is elongated and bro- ken into parts in the drawing direction. The strengthening effect of nano-Y2O3 and nano-ceo2 keeps the finer grains and superior tensile properties for Mo-0.15Y-0.15Ce wire.

关键词： nano-Y2O3 nano-ceo2 Mo alloy wire Microstructure Tensile property Fracture surface

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镁合金表面纳米二氧化铈/磷酸盐复合转化膜的制备及其防护性能

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材料保护 2017年第5期50卷 23-27,38页

作者：杨峻周勇熊金平闫福安武汉工程大学邮电与信息工程学院湖北武汉430073 武汉工程大学绿色化工过程教育部重点实验室湖北武汉430205 北京化工大学材料电化学过程与技术北京市重点实验室北京100029

添加纳米颗粒可改善金属表面膜层的性能,但目前添加纳米颗粒改善镁合金表面磷化膜性能的报道较少。通过向磷化处理液中添加纳米二氧化铈(nano-ceo_2)颗粒在镁合金表面制备了一层纳米二氧化铈/磷酸盐复合转化膜,采用X射线衍射仪(XRD)、X... 详细信息

添加纳米颗粒可改善金属表面膜层的性能,但目前添加纳米颗粒改善镁合金表面磷化膜性能的报道较少。通过向磷化处理液中添加纳米二氧化铈(nano-ceo_2)颗粒在镁合金表面制备了一层纳米二氧化铈/磷酸盐复合转化膜,采用X射线衍射仪(XRD)、X射线光电子能谱(XPS)、电化学阻抗谱(EIS)和极化曲线等手段研究了添加nano-ceo_2颗粒对膜层成分和防护性能的影响,讨论了nano-ceo_2颗粒的作用机制。结果表明:复合转化膜的相成分为Zn_3(PO_4)_2·4H_2O、Zn_2Mg(PO_4)_2和ceo_2,在单组分磷化膜成分的基础上多出了ceo_2相。在硼酸缓冲溶液中,单组分磷化膜的膜层电阻(R_c)和低频阻抗值(R_(0.01 Hz))分别为561.74 kΩ·cm^2和938.11 kΩ·cm^2,而复合转化膜的R_c和R_(0.01 Hz)分别为2 428.98 kΩ·cm^2和3 985.61 kΩ·cm^2;与此同时,覆盖复合转化膜镁合金的腐蚀电流密度为4.05×10^(-7)A/cm^2,而覆盖单组分磷化膜镁合金的为8.38×10^(-6)A/cm^2,R_c和R_(0.01 Hz)的增大以及J_(corr)的减小说明复合转化膜的防护作用明显优于单组分磷化膜的防护作用。nano-ceo_2颗粒的作用机制主要归因于两个方面:第一,nano-ceo_2颗粒在处理液中的添加有利于磷酸盐晶核的形成;第二,nano-ceo_2颗粒作为一种不溶性固体粒子在膜层中的存在可以强化膜层的物理屏蔽效应。

关键词：镁合金磷化膜 nano-ceo2 耐蚀性 XPS EIS

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