共查询到19条相似文献,搜索用时 78 毫秒
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《微纳电子技术》2020,(2):119-124
以柠檬酸为原料,通过碳化制备石墨烯量子点(GQD)溶液,对制备的石墨烯量子点溶液进行超声使石墨烯量子点吸附在石墨毡表面。采用场发射扫描电子显微镜(FE-SEM)、X射线光电子能谱(XPS)和喇曼光谱对石墨烯量子点修饰的石墨毡进行表征。通过循环伏安(CV)曲线、电化学阻抗谱(EIS)和计时电位法研究其电化学性能。测试发现,该石墨毡电极在电流密度1 mA·cm-2下比电容高达2 394 F/g,在电流密度4 mA·cm-2下经过5 000次循环后稳定性达到95%。结果表明石墨烯量子点修饰的石墨毡电极具有优异的电化学性能,可以成为极具应用前景的超级电容器的电极材料。 相似文献
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将石墨衬底浸泡于0.5mol/LNi(NO3)2溶液中一段时间,之后利用低压化学气相沉积法在不同温度的条件下生长碳纳米管薄膜。研究了碳纳米管的生长温度对其场发射性能的影响。通过扫描电子显微镜和拉曼光谱对生长的碳纳米管薄膜的表征发现,随着碳纳米管的生长温度的增加,碳纳米管的直径与相应拉曼光谱中的G峰和D峰(ID/IG)的峰强比减小。同样,碳纳米管的G峰的半峰宽随着碳纳米管的生长温度的增加而减小,这表明碳纳米管的石墨化程度的增强。实验中发现,碳纳米管的场发射性能依赖于碳纳米管的生长温度。 相似文献
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金属-有机框架(MOF)衍生的过渡金属硒化物和多孔碳纳米复合材料具有巨大的储能优势,是应用于电化学储能的优良电极材料。采用共沉淀法制备CoFe类普鲁士蓝(CoFe-PBA)纳米立方,并通过静电组装在CoFe-PBA上包覆聚吡咯(PPy)得到CoFe-PBA@PPy;通过在400℃氮气中退火并硒化成功制备了氮掺杂的碳(NC)包覆(CoFe)Se2的(CoFe)Se2@NC纳米复合材料,并对其结构和形貌进行了表征。以(CoFe)Se2@NC为电极制备了超级电容器,测试了其电化学性能,结果表明,在电流密度1 A/g时超级电容器的比电容达到1047.9 F/g,在电流密度5 A/g下1000次循环后具有良好的循环稳定性和96.55%的比电容保持率。由于其性能优越、无毒、成本低和易于制备,未来(CoFe)Se2@NC纳米复合材料在超级电容器中具有非常大的应用潜力。 相似文献
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以芦丁为碳源、乙二胺为氮源,采用水热法制备氮掺杂芦丁基碳点(N-CD)。通过优化温度、时间、碳源质量等反应条件得到N-CD荧光最大值。将N-CD作为基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)基质对氨基酸进行检测。结果显示:氮原子在N-CD中主要以吡啶氮形式存在,氮原子的孤电子对与碳点的sP2芳香体系以垂直形式构成的共轭结构,增大了共结晶电子解吸/电离效率。使用N-CD对谷氨酸、组氨酸、苯丙氨酸和天冬氨酸进行检测。检测结果表明氨基酸离子信号强度最高可达30 382。N-CD溶液作为基质最佳质量浓度为0.5 mg/mL,最大耐盐度为1 mol/L,初步实现对人体血清中氨基酸进行高通量检测。N-CD作为MALDI-TOF-MS新型基质材料在分析化学检测、环境检测以及生物小分子检测中具有良好的应用潜力,也为多元素掺杂生物质碳点材料作为MALDI-TOF-MS基质提供了参考。 相似文献
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利用一种简便的一步溶剂热法合成了氮/铝共掺杂碳点,该碳点的水溶液在红光发射区的发光量子效率达30%.分别通过原子力显微镜(AFM)、动态光散射(DLS)粒度分析仪、荧光光谱仪、X射线光电子能谱仪(XPS)和傅里叶变换红外光谱仪(FTIR)等对其颗粒尺寸、表面化学结构及荧光性能进行了表征.所合成的氮/铝共掺杂碳点颗粒的平... 相似文献
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氢氧化镍(Ni(OH)2)是碱性二次电池的正极材料,本文采用化学沉淀法制备了纳米Ni(OH)2超微粉体,XRD检测证实晶型为β相,用TEM对粉体进行形貌分析,结果表明所得产物是颗粒状纳米晶,粒径20nm左右.将纳米Ni(OH)2粉以10%的比例掺杂到常规球镍中制得纳米复合β-Ni(OH)2电极材料,其电化学容量和放电平台较常规球镍有很大提高,大电流放电时,纳米复合β—Ni(OH)2电极材料的电化学容量比常规球镍提高达40.9%。 相似文献
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Anton Weissbach Matteo Cucchi Hsin Tseng Karl Leo Hans Kleemann 《Advanced functional materials》2023,33(46):2302205
Organic electrochemical transistors (OECTs) have gained enormous attention due to their potential for bioelectronics and neuromorphic computing. However, their implementation into real-world applications is still impeded by a lack of understanding of the complex operation of integrated OECTs. This study, for the first time, elaborates on a peculiar behavior that integrated OECTs exhibit due to their electrolytic environment—the electrochemical electrode coupling (EEC), which has severe implications on the device and circuit performance, causing a loss of output saturation and a threshold voltage roll-off. After developing a physical model to describe this effect, it is substantiated with experimental data, and the crucial role of the gate electrode is discussed. Furthermore, the impact of the electrode/channel overlap on the saturation in the output curve is evaluated. It is then investigated how its detrimental effect on circuit performance can be minimized, and the optimization of a simple logic gate is demonstrated. This study has fundamental implications for researchers exploring materials and device architectures for OECTs and for engineers designing integrated OECT-based circuits. 相似文献
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Developing scalable methods to produce large quantities of high‐quality and solution‐processable graphene is essential to bridge the gap between laboratory study and commercial applications. Here an efficient electrochemical dual‐electrode exfoliation approach is developed, which combines simultaneous anodic and cathodic exfoliation of graphite. Newly designed sandwich‐structured graphite electrodes which are wrapped in a confined space with porous metal mesh serve as both electrodes, enabling a sufficient ionic intercalation. Mechanism studies reveal that the combination of electrochemical intercalation with subsequent thermal decomposition results in drastic expansion of graphite toward high‐efficiency production of graphene with high quality. By precisely controlling the intercalation chemistry, the two‐step approach leads to graphene with outstanding yields (85% and 48% for cathode and anode, respectively) comprising few‐layer graphene (1–3 layers, >70%), ultralow defects (ID/IG < 0.08), and high production rate (exceeding 25 g h?1). Moreover, its excellent electrical conductivity (>3 × 104 S m?1) and great solution dispersibility in N‐methyl pyrrolidone (10 mg mL?1) enable the fabrication of highly conductive (11 Ω sq?1) and flexible graphene films by inkjet printing. This simple and efficient exfoliation approach will facilitate the development of large‐scale production of high‐quality graphene and holds great promise for its wide application. 相似文献
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Yang Hou Xin‐Yong Li Qi‐Dong Zhao Xie Quan Guo‐Hua Chen 《Advanced functional materials》2010,20(13):2165-2174
An electrode with intimate and well‐aligned ZnFe2O4/TiO2 composite nanotube arrays is prepared via electrochemical anodization of pure titanium foil in fluorine‐containing ethylene glycol, followed by a novel cathodic electrodeposition method. The deposition of ZnFe2O4 is promoted in the self‐aligned, vertically oriented TiO2 nanotube arrays but minimized at the tube entrances. Thus, pore clogging is prevented. Environmental scanning electron microscopy, energy‐dispersive X‐ray spectra, high‐resolution transmission electron microscopy, X‐ray diffraction patterns, and X‐ray photoelectron spectroscopy indicate that the as‐prepared samples are highly ordered and vertically aligned TiO2 nanotube arrays with ZnFe2O4 nanoparticles loading. The TiO2 nanotubes are anatase with the preferential orientation of <101> plane. Enhanced absorption in both UV and visible light regions is observed for the composite nanotube arrays. The current–voltage curve of ZnFe2O4‐loaded TiO2 nanotube arrays reveals a rectifying behavior. The enhanced separation of photoinduced electrons and holes is demonstrated by surface photovoltage and photocurrent measurements. Meanwhile, the photoelectrochemical investigations verify that the ZnFe2O4/TiO2 composite nanotube array modified electrode has a more effective photoconversion capability than the aligned TiO2 nanotube arrays alone. In addition, the photoelectrocatalytic ability of the novel electrode is found enhanced in the degradation of 4‐chlorophenol. 相似文献