NiO微球的微波辅助合成及电荷传导能力优化（英文）

为了优化电荷传导特性,提高电极的电化学性能,本工作采用微波辅助合成了分级多孔结构的氧化镍微球。通过XRD、SEM和TEM对产物的形貌进行了表征。研究结果表明,开放多孔结构的氧化镍微球是由极薄纳米片自组装而成,以硫酸镍为镍源,得到的氧化镍微球的粒径约为2μm。作为超级电容器电极材料,在电流密度为0.5 A/g时,电极的比容量达到455 F/g,由于NiO微球独特的多孔特性,使电极表现出良好的阻抗特性,为法拉第反应过程提供了较多的活性反应点,从而提高了电极的电容性能。     

Co_3O_4纳米片/碳微球复合物的制备及其超级电容器性能研究

利用简单的低温水热法和后续高温煅烧,将Co_3O_4纳米片成功的生长在碳微球表面。X-射线衍射(XRD)和场发射扫描电镜(FE-SEM)测试表明,Co_3O_4纳米片自组装呈疏松状包覆于碳微球表面,纳米片之间相互交织形成三维多孔结构,丰富的孔道极有利于电解质离子在电极材料活性物质中的迁移和渗透。将其作为工作电极,表现出较高的电容性能,电流密度为1A/g时比电容达184F/g,当电流密度达5A/g时电容保持率为82.6%,电极材料具有良好的倍率特性。     

分级多孔活性炭的KOH再活化法制备及其电化学性能

首先利用水热法以葡萄糖为碳源合成炭微球,然后采用KOH再活化法将炭微球制备成分级多孔活性炭,最后测试并表征其作为超级电容器电极材料的电化学性能。结果表明:KOH再活化法具有扩孔和再造孔的双重作用,可获得具有较高的比表面积、合适的分级多孔结构和良好的石墨化程度的分级多孔活性炭材料;在Na2SO4中性电解液中,在电流密度为1 A/g时,分级多孔活性炭材料的比电容可达209 F/g,表现出优异的电化学性能。     

纳米氧化镍的制备及超级电容性能研究

以NiSO4·6H2O和NaOH为原料,采用常温合成-水热改性-中温焙烧工艺制备了分散性好、平均粒径约为40nm的规则六角片状形貌的氧化镍电极材料.利用循环伏安和恒流充放电对氧化镍制备的电极的电容性能进行了研究,结果表明,NiO电极在KOH电解液中具有良好的超电容特性和循环寿命,在充放电电流为20mA时,NiO电极的比容量达到252F/g.     

中间相沥青基活性炭微球/聚苯胺复合材料的制备及其电化学性能研究

采用原位聚合法,以过硫酸铵为氧化剂,在比表面积为2945cm2/g的中间相沥青基活性炭微球(AMCMB)表面引发苯胺聚合,制备中间相沥青基活性炭微球/聚苯胺复合材料(AMCMB/PANI)。利用扫描电镜、X射线衍射和傅里叶变换-红外光谱分析,考察其微观结构和表面形貌;通过恒流充放电、循环伏安及交流阻抗测试,研究其在6mol/L KOH溶液中的电化学性能。在电流密度为0.02A/g时,AMCMB/PANI电极的比容量为387.72F/g,与AMCMB电极的比容量相比,提高了57.46%,说明少量聚苯胺的加入可以显著地提高电极材料的比容量;当电流密度增大1000倍时,AMCMB/PANI电极的比容量为157.68F/g,表现出好的大电流充放电能力。     

介孔氧化镍微球的水热-热分解法制备及其在血红蛋白直接电化学检测中的应用

以聚乙二醇-6000为模板剂,Ni(NO3)2.6H2O为镍源,通过微波水热法合成了Ni(OH)2前驱体微球,再采用热分解法最终获得介孔氧化镍微球,并对样品XRD、SEM、TEM和N2吸-脱附等结构表征。利用涂布法以离子液体为粘合剂,制备了固定血红蛋白(Hb)的复合工作电极,并对吸附于膜内的Hb电化学行为进行了研究。结果表明采用水热-热分解法可以获得直径为2.0μm颗粒堆积介孔氧化镍微球,该氧化镍微球具有高的比表面积(234m2/g)和窄的孔径分布(3.25nm)。循环伏安实验表明,在pH值=7.0的磷酸缓冲溶液中,Hb表现出一对峰型良好的准可逆氧化还原峰,为Hb Fe(Ⅲ)/Fe(Ⅱ)电对的特征峰,对其直接电化学行为进行了研究,求出电位为-0.278V(vs Ag/AgCl),电子转移数为1.104,电荷传递系数为0.476,表观异相电子转移速率常数为0.775s-1。     

水热法合成二硫化钼花状微球及其电容性能研究

使用水热法以钼酸铵为钼源,硫脲为硫源制备了由纳米片组成的三维花状的二硫化钼微球。利用XRD、Raman、SEM和TEM对产物的微观结构和形貌进行了表征。同时通过循环伏安法、恒电流充放电和交流阻抗谱研究了其作为超级电容器电极材料的电化学性能。测试表明MoS2花状微球电极材料在电流密度为0.5A/g时,比电容可达225F/g,具有良好的倍率性能,是一种性能优异的超级电容器电极材料。     

碳纳米管表面沉积氧化镍及其超电容器的电化学行为

通过催化裂解法制备了碳纳米管并进一步制备了碳纳米管薄膜电极.基于该种材料的超电容器电极比容量达到36F/g.研究了在碳纳米管薄膜基体上使用电化学方法沉积氧化镍的新工艺,制备出碳纳米管和氧化镍的复合电极.电化学测试证明复合电极的比容量提高到52F/g以上且基于这种复合电极的超电容器具有极低的自放电率.     

聚酰亚胺基氮掺杂碳电极材料的制备及电化学性能研究

由于氮掺杂多孔碳材料不仅保留原有材料的高比表面积、高孔隙率和发达的孔道结构等优势,还兼具杂原子良好的润湿性能和导电性,被广泛应用于超级电容器电极材料的研究。以均苯四甲酸二酐(PMDA)和4,4′-二氨基二苯醚(ODA)为原料,通过水热法,在高温高压的条件下,分子链进行“自上而下”的折叠,形成三维纳米微球结构。借助对纳米球的高温热解,使氮元素保留在碳材料中,得到含有大量微孔和介孔结构的掺杂氮碳微球。当碳化温度达到800℃时,PI碳球具有709.39m²/g的高比表面积和良好的氮掺杂率,很大程度上提高了此类电极材料的比电容和润湿性能。电化学测试表明,当扫描速率为0.5A/g时,电极材料能够达到253.6F/g的比电容,且在电流密度达到10A/g时,电极材料的电容保持率为59.6%。同时,在循环10000次后,比电容保持率出现涨幅达到105%,具有优异的循环稳定性。综上,通过自组装和氮掺杂的有效结合,制备的3D氮掺杂多孔碳微球具有理想的电化学性能,为制备超级电容器电极材料提供了一种可供参考的工艺。     

玉米淀粉基碳微球的制备及电化学性能的研究

以玉米淀粉为原料,经过乙酸镍处理后在不同温度下碳化,再用KOH对碳化材料进行活化,得到玉米淀粉基碳微球,该材料可做成超级电容器。采用扫描电子显微镜(SEM)对实验样品形貌进行表征,并且进行了循环伏安、恒流充放电等电化学性能测试。SEM结果显示,原料玉米淀粉呈片状,而实验制得的玉米淀粉基碳微球具有良好的球形外貌,表面光滑平整。电化学性能结果显示,经900℃碳化并活化后的玉米淀粉基碳微球表现的电容特性最佳。在6mol/L KOH电解液中,200mV/s的扫描速度下,其循环伏安曲线仍能保持高度类矩形形状;在电流密度为1A/g恒流充放电下,其比容量高达116F/g,且经过500次充放电循环后,依然保持初始值的98%的比电容。结果表明,乙酸镍能促进淀粉球很好地形成球状的碳微球,且活化后的玉米淀粉基碳微球表面粗糙,产生了多孔结构,比表面积增大,电化学性能大大提高。     

NiO/PB复合电致变色薄膜的制备及其性能研

采用水热法制备了垂直生长的氧化镍(NiO)纳米片薄膜, 并利用电沉积法将普鲁士蓝(PB)负载到NiO纳米片薄膜上, 制备了新型的NiO/PB复合电致变色薄膜。利用X射线衍射仪(XRD)、场发射扫描电镜(SEM)对样品的晶型以及微观形貌进行了表征, 采用紫外-可见光光度计以及电化学工作站对NiO/PB复合薄膜的电化学和电致变色性能进行了研究和表征。结果表明: NiO/PB复合电致变色薄膜具有多孔结构和较大的比表面积, 可以增大电解质与电极材料的接触面积。PB成功负载到NiO薄膜表面, 使NiO/PB复合薄膜表现出较大的电流密度。相比于单层NiO薄膜, NiO/PB复合薄膜表现出更好的电致变色性能, 其光调制范围可以达到46%, 着色效率为141 cm²/C, 并且其着色时间可以缩短到5 s, 褪色时间为6 s。     

Microwave-mediated synthesis for improved morphology and pseudocapacitance performance of nickel oxide

Synthetic methods greatly control the structural and functional characteristics of the materials. In this article, porous NiO samples were prepared in conventional-reflux and microwave assisted heating method under homogeneous precipitation conditions. The NiO samples synthesized in conventional reflux method showed flakelike morphology, whereas the sample synthesized in microwave methods showed hierarchical porous ball like surface morphology with uniform ripple-shaped pores. The NiO samples characterized using BET method were found to bear characteristic meso- and macroporosity due to differently crystallized Ni(OH)(2) precursors under various heating conditions. Thermogravimety analysis showed morphology dependent decomposition of Ni(OH)(2) precursors. The microwave synthesized porous NiO sample with unique morphology and pore size distribution showed significantly improved charge storage and electrochemical stability than the flaky NiO sample synthesized by employing conventional reflux method. The cyclic voltammetry measurements on microwave synthesized NiO sample showed considerably high capacitance and better electrochemical reversibility. The charge-discharge measurements made at a discharge current of 2 A/g showed higher rate specific capacitance (370 F/g) for the NiO sample synthesized by microwave method than the sample synthesized by reflux method (101 F/g). The impedance study illustrates lower electronic and ionic resistance of rippled-shaped porous NiO due to its superior surface properties for enhanced electrode-electrolyte contact during the Faradaic redox reactions. It has been further established from the Ragone plot that the microwave synthesized NiO sample shows higher energy and power densities than the reflux synthesized NiO sample. Broadly, this study reveals that microwave-mediated synthesis approach is significantly a better strategy for the synthesis of porous NiO suitable to electrochemical supercapacitor applications.     

Synthesis of nickel oxides nanoparticles on glassy carbon as an electron transfer facilitator for horseradish peroxidase: Direct electron transfer and H2O2 determination

In this study, horseradish peroxidase/nickel oxides nanoparticles/glassy carbon (HRP/NiO NPs/GC) electrode was prepared by first applying nickel oxides nanoparticles on glassy carbon surface and then horseradish peroxidase immobilized on the NiO NPs. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) have been used as a diagnostic tools to identify the synthesized NiO NPs. Immobilized HRP showed an electrochemical redox behavior pertained to HRP(Fe(III)–Fe(II)) by direct electron transfer between protein and nanoparticles with a formal potential (E^0′) of ? 55.5 mV (vs. Ag/AgCl and 141.5 mV vs. NHE) in 50 mM phosphate buffer solution (PBS). The anodic charge transfer coefficient (α) and heterogeneous electron transfer rate constant (k_s) were 0.42 and 0.75 s^? 1, respectively. Biocatalytic activity of HRP/NiO NPs/GC electrode for reduction of hydrogen peroxide and application to hydrogen peroxide determination was exemplified.     

Chemical adsorption of NiO nanostructures on nickel foam-graphene for supercapacitor applications

Few-layer graphene was synthesized on a nickel foam template by chemical vapor deposition. The resulting three-dimensional (3D) graphene was loaded with nickel oxide nanostructures using the successive ionic layer adsorption and reaction technique. The composites were characterized and investigated as electrode material for supercapacitors. Raman spectroscopy measurements on the sample revealed that the 3D graphene consisted of mostly few layers, while X-ray diffractometry and scanning electron microscopy revealed the presence of nickel oxide. The electrochemical properties were investigated using cyclic voltammetry, electrochemical impedance spectroscopy, and potentiostatic charge–discharge in aqueous KOH electrolyte. The novelty of this study is the use of the 3D porous cell structure of the nickel foam which allows for the growth of highly conductive graphene and subsequently provides support for uniform adsorption of the NiO onto the graphene. The NF-G/NiO electrode material showed excellent properties as a pseudocapacitive device with a high-specific capacitance value of 783 F g^?1 at a scan rate of 2 mV s^?1. The device also exhibited excellent cycle stability, with 84 % retention of the initial capacitance after 1000 cycles. The results demonstrate that composites made using 3D graphene are versatile and show considerable promise as electrode materials for supercapacitor applications.     

AC+Li（NiCoMn）O2/Li4Ti5O12+MWCNTs混合型电容器EI北大核心CSCD

以钛酸锂(Li 4Ti 5O 12)/多壁碳纳米管(MWCNTs)复合材料为负极、活性炭(AC)/镍钴锰酸锂(Li(NiCoMn)O 2)复合材料为正极,组装成混合型电容器并研究其电化学性能。利用扫描电子显微镜(SEM),透射电子显微镜(TEM),X射线衍射仪(XRD),拉曼光谱仪(Raman),热重分析仪(TGA)对电极材料进行分析,通过恒流充放电(GCD)和交流阻抗谱(EIS)研究混合型电容器的电化学性能。结果表明:掺杂适量MWCNTs和镍钴锰酸锂可提高电容器的电化学性能。当MWCNTs质量分数为5%时,在电流密度为0.1 A/g下恒流充放电时比容量达161.5 mAh/g。在0.1~1 A/g时,最大功率密度和最大能量密度分别为993.2 W/kg和52.2 Wh/kg。5000周次恒流充放电循环后,容量保持率在92.2%左右,库仑效率仍有99.1%,展现出较高的能量密度和功率密度,并具有优异的循环性能。     

Preparation and electrochemical properties of multiwalled carbon nanotubes-nickel oxide porous composite for supercapacitors

Porous nickel oxide/multiwalled carbon nanotubes (NiO/MWNTs) composite material was synthesized using sodium dodecyl phenyl sulfate as a soft template and urea as hydrolysis-controlling agent. Scanning electron microscopy (SEM) results show that the as-prepared nickel oxide nanoflakes aggregate to form a submicron ball shape with a porous structure, and the MWNTs with entangled and cross-linked morphology are well dispersed in the porous nickel oxide. The composite shows an excellent cycle performance at a high current of 2 A g⁻¹ and keeps a capacitance retention of about 89% over 200 charge/discharge cycles. A specific capacitance approximate to 206 F g⁻¹ has been achieved with NiO/MWNTs (10 wt.%) in 2 M KOH electrolyte. The electrical conductivity and the active sites for redox reaction of nickel oxide are significantly improved due to the connection of nickel nanoflakes by the long entangled MWNTs.     

煤基球形多孔碳用于锂离子电池负极材料的性能研

因具有较短的锂离子扩散路径、大的比表面积等优势, 球形碳材料在锂离子电池负极材料中展露出良好的应用前景。研究以新疆库车产煤为原料, 采用电弧放电法及化学活化法制备出了具有多孔结构的煤基球形碳。通过X射线衍射(XRD)、扫描电镜(SEM)、拉曼光谱(Raman)、氮气吸脱附法和恒电流充放电等测试手段对材料结构、形貌和电化学性能进行了表征。结果表明, 在100 mA/g的电流密度下, 煤基球形多孔碳的首次放电比容量可达到1188.9 mAh/g, 远高于商业石墨负极372 mAh/g的理论比容量。此外, 该材料还表现出了良好的循环稳定性, 经历200圈循环后的放电比容量为844.9 mAh/g。煤基球形多孔碳优异的电化学性能得益于活化过程所产生的分级孔道结构能为锂离子提供更多储存空间, 从而提高了电极的容量及循环稳定性。     

Hydrothermal process fabrication of NiO–NiCoO<Subscript>2</Subscript>–Co<Subscript>3</Subscript>O<Subscript>4</Subscript> composites used as supercapacitor materials

A composite consisting of Co₃O₄, NiCoO₂ and NiO is prepared by a simple and easy hydrothermal method followed by calcining at 300?°C. The composition, morphology and microstructure of NiO–NiCoO₂–Co₃O₄ composites are examined by X-ray diffraction, field emission scanning electron microscope and transmission electron microscopic. The electrochemical performances of NiO–NiCoO₂–Co₃O₄ composites are characterized by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy in 3 M KOH electrolyte. The results of electrochemical measurements show that the NiO–NiCoO₂–Co₃O₄ composites exhibit a high specific capacitance of 990 and 580 F/g at the current densities of 1.0 and 10 A/g, respectively. About 50% of the maximum specific capacitance can still be retained after 1000 continuous CD cycles at 10 A/g. It reveals a great potential of NiO–NiCoO₂–Co₃O₄ composites used in high-performance energy-storage systems.     

Non-basic solution eco-routes to nano-scale NiO with different shapes: Synthesis and application

The assembly of NiO nanodiscs (namely nanoflowers) as well as the dispersed NiO nanodiscs have been successfully synthesized via the thermal decomposition of Ni(OH)₂ obtained from different Ni sources in non-basic solution. The route is environment-friendly. The materials were characterized by X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM) and N₂ adsorption–desorption. The porous structures with pore size around 6 nm can be observed on the single NiO disc. The nanoflowers exhibit better performance than nanodiscs in the electrochemical test and water treatment experiments, due to much more available surface areas and spaces formed in the NiO nanoflowers.     

3D ordered NiO/silicon MCP array electrode materials for electrochemical supercapacitors

The preparation and electrochemical properties of 3D ordered nickel oxide/silicon microchannel plate (NiO/Si-MCP) array electrode materials for supercapacitors are studied. The Si-MCP fabricated by electrochemical etching is used as a 3D supporting structure for electrodes. The active NiO is synthesized by electroless plating of nickel on the surface of the Si-MCP followed by annealing under oxygen. The electrochemical properties of the NiO/Si-MCP nanocomposite electrode materials are studied using cyclic voltammetry (CV), chronopotentiometry, and electrochemical impedance spectroscopy (EIS) in a 2 M KOH solution. The results reveal typical electrochemical capacitive behavior in the potential range from −0.6 to 1.0 V. The specific capacitance of approximately 586.4 F g⁻¹ decreases slightly with 4.8% loss after 500 cycles. The linear and symmetrical charge/discharge curves are measured by chronopotentiometry. The NiO/Si-MCP composite is a promising electrode material for integrated supercapacitors.