共查询到18条相似文献,搜索用时 508 毫秒
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两种非晶锂离子导体B2O3-0.7Li2O-0.7LiCl-xAl2O3-0.1V2O5(x=0.05和0.15)的电子自旋共振谱研究表明:(i)ESR线型是高斯型,证实V2O5添加量适当;(ii)超精细结构来源于VO2+络离子,具有四角对称性,属C4v群。越精细耦合张量的平行分量平均值A//=0.0175cm-1,垂直分量A⊥=0.0063cm-1。由g//(g⊥)求出其基态2B2g与第一激发态2Eg的能级间距△1=2.46×104 cm-1,基态与第二激发态2B1g的能级间距△2=3.03×104 cm-1;(iii)变温实验证实:Al2O3组分较少(x=0.05)的非晶ESR强度比x=0.15的非晶高3倍至2倍,而Al2O3组分越多则ESR强度随温升下降越小。 相似文献
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羟基自由基(·OH)被公认是生物系统中最具活性的活性氧物种,能导致生物体内DNA等生物大分子氧化损伤. 目前,最被广泛接受的·OH的产生机理是过渡金属离子催化的Fenton反应. 五氯酚(PCP)是一种重要的生物杀灭剂,主要用作木材保护. 采用电子自旋共振二级自旋捕获等分析手段,发现H2O2和五氯酚的代谢产物之一四氯苯醌(TCBQ)能通过不依赖于金属离子的途径产生·OH;进一步的研究发现是TCBQ,而非其相应的半醌自由基对·OH的产生极其重要. 基于这些数据和分析,提出以下新型·OH产生分子机理:H2O2对TCBQ进行亲核攻击形成不稳定的三氯氢过氧基苯醌中间产物,其可均裂产生·OH. 综合采用电子自旋共振自旋捕获和其他分析方法,第1次检测到一种新型的以碳为中心的醌自由基. 相似文献
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Al2O3-SiO2石油裂化催化剂上自由基空间分布的ESR成象 总被引:2,自引:2,他引:0
报道了用自己设计制作的电子自旋成象装置,对芳烃芳胺化合物在Al2O3-SiO2催化剂表面酸中心所形成的正离子自由基进行二维ESR成象研究. 相似文献
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用Na2O2-DMSO体系产生O2·的ESR研究 总被引:6,自引:0,他引:6
提出了Na2O2的二甲基亚砜(DMsO)/H2O溶液中产生超氧阴离子自由基(O2·)的新方法,用电子自旋共振仪(ESR)可直接检测到很强的O2·信号,研究了反应的条件及其O2·信号的特性,并用该法考察了茶多酚等清除剂对于超氧阴离子自由基的清除作用。结果表明本体系是产生O2·的有效方法,可用于超氧阴离子自由基清除剂的研究。 相似文献
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具有手性晶体结构的MnSb2O6其基态为螺旋磁序,对外磁场有着响应丰富的铁电性.本文通过助熔剂法制备了高质量MnSb2O6单晶.电子自旋共振谱(ESR)的结果表明其共振场具有类似铁磁材料的各向异性温度依赖关系.这一结果表明MnSb2O6基态的螺旋磁序在外磁场中形成了随磁场方向转动的圆锥磁序相(conical phase).对共振峰半高宽的进一步拟合得到一个意外小的临界指数,这表明MnSb2O6中的磁矩具有二维特征并且存在着较强的竞争相互作用. 相似文献
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利用溶胶-凝胶技术与电子束蒸镀相结合的方法在常温下制备了叠层V2O5/Ag/V2O5(VAV)透明导电薄膜,研究了各层薄膜厚度对叠层结构光电特性的影响。用原子力显微镜、紫外-可见光分光光度计、四探针电阻仪及开尔文探针对样品的表面形貌、光电性能及功函数等性质进行了表征。实验结果表明,该薄膜具有良好的光学和电学性质,可见光(380~780 nm)平均透过率达75%,迁移率为16.89 cm2/(V·s),载流子浓度为-1.043×1022 cm-3,方块电阻值为15.1 Ω/□,功函数为5.17 eV。该制备方法降低了V2O5薄膜的工艺制备难度,为该材料在太阳能电池中的应用创造了良好的前期基础。 相似文献
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Baohe Yuan 《中国物理 B》2022,31(3):38203-038203
Among all the known electrode materials, vanadium pentoxide (V2O5) has high reversible capacity. It is a very valuable material for research of the complexity, rich structure and morphology. However, it also has some disadvantages, such as poor cycle stability, low discharge voltage, low conductivity and Li+ diffusion coefficient. In this regard, researchers have carried out a lot of research, such as using various methods to improve the nanostructures, introducing heterostructures, introducing point defects or cation doping in the crystal structure, etc. The electrochemical performance of V2O5 has been significantly improved in reversible capacity, high-rate capacity and long-term cycle stability. In this paper, V2O5 based nanostructure with different chemical composition are briefly introduced, and it covers V2O5 nanomaterials with different morphology, including 1D nanorods, nanobelts, nanotubes, 2D leaf like nanosheets and other nanosheets, and 3D hollow structures, porous nanostructures, porous eggshell microsphere structures. The composite nanomaterials of V2O5 and different carbonaceous supports are also introduced. Finally, the V2O5 composite materials doped with cations are discussed. The electrochemical performance of V2O5 based electrode can be improved effectively by obtaining appropriate nanostructure and optimized chemical composition. 相似文献
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Vanadium pentoxide xerogels have shown high electrochemical performance in terms of energy content. The high specific energy and high intercalation capability make the materials promising for thin film lithium battery and electrochromic device applications. In order to enhance the rate capabilities of the host we increased the electronic conductivity by doping the V2O5 xerogels with silver. Samples were prepared by mixing various amounts of silver powder with V2O5 hydrogel. We were able to prepare silver-doped vanadium pentoxide dip-coated thin films with a molar ratio (Ag/V) ranging from 0.005 to 0.5 (AgyV2O3 with y = 0.01, 0.1 and 1). With the successful doping, the electronic conductivity of V2O5 was increased by 2 to 3 orders of magnitude. The insertion capacity of the material was maintained and up to 4 moles of lithium per mole of silver-doped V2O5 (XRG) were found to be reversibly intercalated. 相似文献
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The effect of nuclear radiation on the chemisorption of oxygen on Cr2O3, Cr2O3-Al2O3 and Cr2O3-SnO2 catalysts has been studied. An iodometric method was used to measure the amount of chemisorbed oxygen; simultaneously the increase in the catalytic activity of the catalyst in the decomposition of H2O2 was determined. It was found that the radiation present within a nuclear reactor promotes the chemisorption of oxygen on chromia (either pure or supported on Al2O3 or SnO2) at temperatures at which such a chemisorption does not normally occur. The radiochemisorption of oxygen on chromia increases with the degree of dispersion of chromia on Al2O3 or SnO2 and is accompanied by an increased catalytic activity of this catalyst in the decomposition reaction of H2O2. It seems that the radiochemisorption is largely due to the action of γ-rays and fast neutrons on the gas. 相似文献
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采用纳米球光刻和金属辅助刻蚀法以p型单晶硅片制备了硅纳米线阵列, 并以此作为基底, 通过溅射不同时长的金属钒薄膜并进行热退火氧化处理, 制备出硅纳米线/氧化钒纳米棒复合材料. 采用扫描电子显微镜和X射线衍射仪表征了该复合材料的微观特性, 结果表明该结构增大了材料的比表面积, 有利于气体传感, 并且镀膜时间对后续生长的氧化钒纳米棒形貌有明显影响. 采用静态配气法在室温下测试了该复合材料对NO2的气敏性能, 气敏测试结果表明沉积钒膜的时间对复合材料的气敏性能影响较大. 当选择合适的镀膜时间时, 适量氧化钒纳米棒增加了材料表面积并形成大量pn结结构, 相比纯硅纳米线对NO2气体的灵敏度有明显提升, 且在室温下表现出优良的选择性. 同时, 对气敏机理做了定性解释, 认为硅纳米线与氧化钒纳米棒之间形成的pn结及能带结构在接触NO2 时的动态变化是其气敏响应提升的主要机制. 相似文献
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Structures of 10AgI-3Ag2O-2V2O5, 3AgI-3Ag2O---2V2O5 and 2AgI---2Ag2O-V2O5 glasses have been investigated by neutron diffraction experiments. The characteristic features of observed structure factors S(Q) in 10AgI-3Ag2O-2V2O5 glass is similar to those of other superionic conducting glasses and molten AgI. From the standpoint of the pair distribution functions, it is clarified that the Ag-I and I-I correlation strength and Ag---Ag correlation length increase with increasing AgI concentration. Observed results suggest that the local AgI structure accompanied by the re-arrangement of silver ions is formed with highly doped iodide ions. 相似文献