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The nanometer MnO2 has outstanding electrochemical performance theoretically, but it is not suitable for actual utilization, which may result in capacity decrease and resource waste. In this study we have utilized the characterizations of the nanometer material, synthesized a type of nanometer α-MnO2 through KMnO4 and KNO3 with hydrothermal method, and mixed the products into micron electrolytic manganese dioxide （EMD） to enhance the electrochemical performance of the electrode.The cyclic voltammogram and galvanostatical discharge measurements of the samples were investigated. It is found that the 50﹪ nanometer MnO2 mixed electrode has the best electrochemical performance. The electrochemical performance improvement mechanism of the sample nanometer MnO2 mixed into micron EMD was discussed. With the existence of electrolyte, the nanometer MnO2 particles filled into the interspaces of the micron EMD particles, the mass and charge transfer conditions of the electrode reaction were improved, and the electrode polarization was diminished. 相似文献
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尖晶石型CoAl2O4纳米粉体的合成及表征 总被引：4，自引：0，他引：4
铝酸钴(CoAl2O4)是目前世界上最耐候、耐光、耐热、耐化学品的尖晶石型钴蓝颜料,为了解决传统钴蓝制备方法存在的能耗高、产品粒径分布不均匀、易团聚等问题,尝试采用柠檬酸盐凝胶法合成了尖晶石型CoAl2O4纳米粉体,对样品进行了TG-DSC、XRD、SEM等分析,考察了前驱体凝胶的热分解过程,以及煅烧温度对CoAl204晶化程度和粒度的影响．确定了钴蓝最佳合成条件为：n(Co^2 )／n(Al^3 )=1：3,柠檬酸与金属离子摩尔比为1：1,pH值约为6．5,煅烧温度为800℃．结果表明,采用柠檬酸盐凝胶法成功合成了平均粒径为60nm,粒度分布均匀的尖晶石型CoAl2O4纳米粉体,该法具有合成成本低、制备工艺简单、易操作等优点． 相似文献
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The sizes and morphologies of hexagonal phase ZnO crystals were successfully controlled by a hydrothermal process in the presence of poly (acrylic acid) (PAA). The dosage of NaOH in this reaction system proved to be crucial in the growth process. With the increase of dosage from 0.7 g to 3.0 g, the morphologies of the ZnO crystals changed from nanoplates to microrods. Their optical properties were also investigated. 相似文献
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用溶胶-凝胶法(sol-gel)制备了纳米荧光粉Y4Al2O9: Eu3+,用X射线粉晶衍射对其进行了物相鉴定,表明在900℃已经得到纯相的Y4Al2O9产物,并用透射电镜对其进行形貌和衍射分析,分析结果证明得到的产物为纳米粉末态晶体,产物Y4Al2O9:Eu3+粒径均匀,大致在20～50nm之间,平均粒径为30nm.并用荧光光度计对其荧光光谱进行了研究,光谱表明Eu3+在Y4Al2O9晶格中占据两种不同的位置.用λ =254nm的紫外光激发Y4Al2O9:Eu3+时,产生两条发光谱带,即由于5 D 0→7 F 1的跃迁产生在峰值λ =590nm处的橙色发光带,和5 D 0→7 F 2跃迁在峰值λ =610nm处的红色发光带. 相似文献
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用KOH、酸处理凹凸棒石、硝酸铝为原料在180℃~200℃水热条件下制备中空的钾霞石。经粉末晶体衍射图证实,所制备的晶体与钾霞石的特征峰符合,表明制备物质为钾霞石。由扫描电镜图中,可以看出所制备的六方片状晶体直径约为5μm~10μm,厚度约为500nm,并且片状中间出现了很多的大孔(直径约100nm~1 000nm左右),这在之前的报道中从未出现过。因此,追踪钾霞石的生长机制,发现这种多孔六方钾霞石生长分为三步,第一步,是纳米棒聚集形成放射状微球;第二步微球晶化形成假六方片钾霞石;第三步,假六方片晶体经过奥斯特瓦尔德熟化过程表面再结晶形成中空六方片。这是首次在二维材料上观察到这种奥斯特瓦尔德熟化再结晶的现象。 相似文献
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Synthesis and Growth Process： A Tetrapod-Like ZnO Nanostructure 总被引：1，自引：0，他引：1
Three kinds of tetrapod-like ZnO nanostructures have been synthesized simultaneously via pure Zn chemical vapor deposition on silicon wafers with (111) orientation (Si (111)) at 920 ℃. X-ray diffraction indicates that the nanotetrapods are of wurtzite structure. The morphology and the microstructure of the nanotetrapods are investigated by the scanning electron microscopy. Selected area electron diffraction shows the growth direction, and energy dispersive X-ray spectroscopy reveals the atomic composition ratio of Zn/O. The growth process is briefly discussed. The optical property of the products was also recorded by means of photoluminescence spectroscopy. 相似文献
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Alloyed ternary CdSxSe1-x nanorods have been synthesized by the thermal treatment of Cd2 -dispersed polyethylene glycol 2 000 gel (PEG 2000) with ethylenediamine solution of sulfur and selenium in a sealed system at 180 ℃ for 24 h, in which the ratio of S to Se in the nanorods was controlled by adjusting the relative amounts of the starting materials. Based on the results of experiments, it is found that the CdSxSe1-x nanorods were also synthesized with several sulfur sources by the method. X-ray diffraction (XRD) shows that the alloyed ternary CdSxSe1-x nanorods are highly crystalline, and no other phase was observed in these nanorods. 相似文献
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