三维石墨烯/氢氧化镍纳米复合材料的制备及电容性能研究

利用电化学沉积法制备三维石墨烯/氢氧化镍纳米Ni(OH)2/3DGR复合材料,通过扫描电镜对样品进行微观形貌表征;在1.0 mo L/L KOH溶液中利用循环伏安和恒电流充放电等方法对纳米复合材料修饰电极进行电化学性能测试.在2 m A/cm2的电流密度下Ni(OH)2/3DGR的比电容达到43.70 m F/cm2;1000次循环充放电测试表明该复合材料具有较长的使用寿命和稳定性,比电容保持率达到79.3%.因此三维石墨烯/纳米氢氧化镍复合材料可以做为一种很好的超级电容器材料.     

三维石墨烯/泡沫镍基底上制备Ni掺杂Co(OH)_2复合材料及其超电容性能

以化学气相沉积法制备的三维网状石墨烯/泡沫镍(3DGE/NF)为基底,电化学沉积Ni掺杂Co(OH)2纳米片得到三维镍钴双氢氧化物/石墨烯/泡沫镍(3D NixCo1-x(OH)2/GE/NF)复合电极材料,研究Ni掺杂量对材料的形貌及电化学性能的影响.结果表明:在Co(OH)2中掺杂适量的Ni可以改善材料的表面形貌;高质量、高导电性石墨烯的存在促进电极与电解液的电荷传输,加上镍钴的协同作用,能有效提高材料的比容量和循环倍率性能.当Ni掺杂量为34%时,3D Ni0.34Co0.66(OH)2/GE/NF复合电极材料具有最佳的电化学性能,当电流密度为3 A/g时,其在1mol/L的KOH电解液中比容量达到1 714F/g,当电流密度升高到30A/g时比容量仍保持有73%达到1 254F/g,显示出较好的倍率性,且在10A/g的大电流密度下经过500次循环后,比容量保持率为83%.     

Ni3S2 -多孔镍@泡沫镍电极制备及其赝电容性能

采用氢气鼓泡法预处理泡沫镍集流体,通过循环伏安法原位电沉积Ni₃S₂活性材料,制备了Ni₃S₂-多孔镍@泡沫镍(Ni₃S₂-Ni@NF)电极.通过扫描电子显微镜(SEM)、X射线衍射(XRD)、光电子能谱(XPS)和拉曼光谱(Raman)对物相结构进行了表征,并利用电化学工作站测试了电化学性能.结果表明:制备的Ni₃S₂-Ni@NF材料表现出优异的赝电容性能,在2 mA/cm2的电流密度下,比电容达到4.56 F/cm2,且具有优异的倍率性能(20 mA/cm2的电流密度下,比电容达到4.06 F/cm2)和循环性能(10 mA/cm2的电流密度下,循环1 000次的比电容保持率约73%).     

Ni(OH)_2-VS_2纳米复合材料的制备及在超级电容器上的应用

采用水热法合成Ni(OH)_2-VS_2纳米复合材料,通过X射线衍射(XRD)、扫描电子显微镜(SEM)等对复合材料物相及形貌进行表征.将所得的复合材料用作超级电容器电极材料,通过循环伏安法、恒电流充放电法以及交流阻抗法对Ni(OH)_2-VS_2纳米复合材料的电化学性能进行评价.同时探讨了Ni(OH)2与VS2的不同质量比对复合材料电化学性能的影响.结果表明:Ni(OH)2与VS2的质量比为5∶1时所制备的Ni(OH)_2-VS_2纳米复合材料具有更优异的电化学性能.在电流密度为1A/g时,比电容最高可达到4021F/g,且在电流密度为5A/g下进行500次充放电测试,电容保持率仍在80%以上.     

球形Ni(OH)_2粒径分布对电化学活性的影响

以不同粒径球形Ni(OH)2为活性材料,以泡沫镍为导电基体,制备氢氧化镍电极,进行活性检测.结果表明,以按一定粒径比例混合的Ni(OH)2为活性物质所制备的电极,其电化学活性最高.     

Ni(OH)_2/SBA-15分子筛复合电极材料的制备与超级电容性能

以SBA-15分子筛为载体,采用简单化学沉淀法制备Ni(OH)2/SBA-15分子筛复合材料,用X射线衍射仪、SEM、TEM和电化学工作站等手段研究复合材料的物相和超级电容性能.结果表明,硫酸改性的SBA-15分子筛比纯SBA-15分子筛具有更高的均一性,孔道发生显著变化,比表面积增大.Ni(OH)2/SBA-15复合材料的表面形貌为纳米尺寸的蜂窝孔状结构,活性材料Ni(OH)2由层状结构的-αNi(OH)2构成.电化学性能测试表明,Ni(OH)2/SBA-15复合材料的比容量随着放电电流密度的增大而降低,随着SBA-15分子筛在复合材料中所占质量分数的增大而降低.采用硫酸改性SBA-15分子筛制备的Ni(OH)2/SBA-15复合材料比采用纯SBA-15分子筛制备的Ni(OH)2/SBA-15复合材料具有良好的超级电容性能和动力学性能,材料最高比容量为1 069 F/g.     

层状结构α-Ni(OH)_2/膨胀石墨纳米复合材料及其电化学性能

以层状膨胀石墨为模板,采用化学浴沉积法首次制备了α-Ni(OH)2/膨胀石墨(α-Ni(OH)2/EG)层状结构的纳米复合材料,分别利用扫描电镜、透射电镜、X射线衍射测试其表面形貌及结构.利用热重分析来检测α-Ni(OH)2在复合材料中的负载量.使用循环伏安和恒流充放电测试等表征其电化学性能.结果表明,制备的α-Ni(OH)2/EG纳米复合材料表现出了优异的电化学性能:在6mol/L KOH电解质溶液中的比电容达到1 180F/g(0.5A/g的电流密度),对应的有效α-Ni(OH)2比电容高达1 920F/g;同时,该复合材料在10A/g的大电流密度下依然能保持较高的比电容(585F/g).优秀的循环稳定性能进一步保证了其成为超级电容器电极材料的合适选择.     

构筑高性能的二氧化锰/石墨烯超级电容器

三维泡沫镍(Ni)基石墨烯(graphene)结构具有理想的自支撑特性,但却受制于有限的容量.以三维Ni基graphene为催化基底,通过一步水热法,在三维Ni基graphene骨架上形成二氧化锰/石墨烯/泡沫镍(MnO2/gra-phene/Ni)的异质结电极.MnO2的形貌随着水热反应温度的增加而呈现出纳米花状、纳...     

Ni(OH)_2/USY分子筛复合材料的制备及其超级电容性能

以USY分子筛为模板,用液相共沉淀方法合成出Ni(OH)2/USY复合材料.用XRD、TEM对Ni(OH)2/USY复合材料的微观结构进行表征分析.结果表明,纳米级高分散、疏松填充的Ni(OH)2材料具有良好的电解质OH-离子电化学可及性和快的扩散速率,循环伏安和恒流充放电测试均表明该材料具有良好的超级电容特性,该材料的单电极比电容高达1 670 F/g.     

多壁碳纳米管与镍纳米颗粒复合物的制备及研究

利用电化学方法制备了多壁碳纳米管与镍纳米颗粒复合物(MWCNTs/Ni).研究了其形貌及对糖类的氧化催化性能.与同样条件制备的镍玻璃碳(GC/Ni)电极比较发现,MWCNTs/Ni具有更好的电化学催化性能,对葡萄糖、蔗糖具有更高的检出灵敏度.     

电沉积铜镍纳米多层膜的机理

采用动电位扫描、循环伏安法以及交流阻抗等方法，研究了从柠檬酸盐体系中电沉积铜镍纳米多层膜的电沉积机理。研究结果表明：在研究体系中铜的沉积是扩散控制的电极过程，而镍的沉积则是首先形成类似Ｎｉ（ＯＨ）ａｄｓ的吸附中间产物，而后在电极上进一步还原为原子态。     

Hydrothermal synthesized porous Co(OH)2 nanoflake film for supercapacitor application

Porous Co(OH)2 film directly grown on nickel foam is prepared by a facile hydrothermal method.The as-prepared Co(OH)2 film possesses a structure consisting of randomly porous nanoflakes with thicknesses of 20-30 nm.The capacitive behavior of the Co(OH)2 film is investigated by cyclic voltammograms and galvanostatic charge-discharge tests in 2 mol/L KOH.The porous Co(OH)2 film exhibits a high discharge capacitance of 935 F g-1 at a current density of 2 A g-1 and excellent rate capability.The specific capacitance keeps a capacitance of 589 F g-1 when the current density increases to 40 A g-1.The specific capacitance of 82.6% is maintained after 1500 cycles at 2 A g-1.     

化学镀钴对Ni（OH）2电极性能的影响

早在１９１４年Ｅｄｉｓｏｎ［１］就发现,在Ｎｉ－Ｃｄ及Ｎｉ－Ｆｅ电极正极材料中添加钴可以有效地改善电极性能．随着近年来研究的不断深入,发现钴对Ｎｉ（ＯＨ）２电极性能的影响主要有［２,３］：增加电极的导电性;提高析氧过电位;提高充电效率．在镍电极中添加...     

Graphene-immobilized flower-like Ni<Subscript>3</Subscript>S<Subscript>2</Subscript> nanoflakes as a stable binder-free anode material for sodium-ion batteries

A binder-free Ni₃S₂ electrode was prepared directly on a graphene-coated Ni foam (G/Ni) substrate through surface sulfiding of substrate using thiourea as the sulfur source in this work. The Ni₃S₂ showed a flower-like morphology and was uniformly distributed on the G/Ni surface. The flower-like Ni₃S₂ was composed of cross-arrayed nanoflakes with a diameter and a thickness of 1-2 μm and~50 nm, respectively. The free space in the flowers and the thin feature of Ni₃S₂ buffered the volume changes and relieved mechanical strain during repeated cycling. The intimate contact with the Ni substrate and the fixing effect of graphene maintained the structural stability of the Ni₃S₂ electrode during cycling. The G/Ni-supported Ni₃S₂ maintained a reversible capacity of 250 mAh·g-1 after 100 cycles at 50 mA·g-1, demonstrating the good cycling stability as a result of the unique microstructure of this electrode material.     

Gas-Liquid Interfacial Plasma engineering under dilute nitric acid to improve hydrophilicity and OER performance of nickel foam

The world has been moving rapidly to find new eco-friendly energy sources. Water electrolysis consists of two reactions of Oxygen Evolution Reaction (OER) and Hydrogen Evolution Reaction (HER), whereas the OER is considered the rate-limiting step. The most commercialized electrode for OER in the alkaline electrolyte is Ni foam, but its original surface is hydrophobic. It is possible to accelerate the adsorption and desorption process of reactants and products during OER by adding hydrophilic functional groups such as –OH on the surface of Ni foam. In this study, a novel Gas-Liquid Interfacial Plasma (GLIP) engineering at room temperature was successfully applied to modify the Ni foam surface dilute (1 ?M) HNO₃ solution. At a current density of 400 ?mA ?cm^?2, GLIP-treated Ni foam electrodes at 1 ?M HNO₃ concentrations showed OER overpotentials of 458 ?mV. Among all, GLIP with 1 ?M HNO₃ treatment of 30 ?min showed 129 ?mV less overpotential than the nickel foam before treatment. In summary, GLIP can be justified as an environmentally friendly and efficient surface treatment to improve the wettability and OER performance of Ni-based electrodes in water electrolysis.     

Voltammetric response and electrocatalysis of glassy carbon electrode modified with monolayer nickel hydroxide

The glassy carbon (GC) electrode modified with a monolayer nickel hydroxide (GC/Ni(OH)₂) was prepared by immersion of GC substrate in 1.0×10⁻³ mol/L NiSO₄ solution, and then cyclic voltammetric scanning in 0.20 mol/L KOH. Similarly, GC/Co (OH)₂ electrode was prepared too. The experiments showed that the voltammetric behavior of GC/Ni (OH)₂ electrode in 0.20 mol/L KOH is more stable than that of GC/Co(OH)₂. It was found that the GC/Ni(OH)₂ electrode acts as an effective electrocatalysis for the oxidation of hydrazine. Supported by the Trans-Century Training Program Foundation for the Talents from the State Commission of Education of China and the National Natural Science Foundation of China Liu Shouqing: born in Dec. 1962. Postgraduate     

气体扩散层集流体对Ni(OH)2纳米结构电化学性能的影响

We report the electrochemical performance of Ni(OH)₂ on a gas diffusion layer (GDL). The Ni(OH)₂ working electrode was successfully prepared via a simple method, and its electrochemical performance in 1 M NaOH electrolyte was investigated. The electrochemical results showed that the Ni(OH)₂/GDL provided the maximum specific capacitance value (418.11 F·g?1) at 1 A·g?1. Furthermore, the Ni(OH)₂ electrode delivered a high specific energy of 17.25 Wh·kg?1 at a specific power of 272.5 W·kg?1 and retained about 81% of the capacitance after 1000 cycles of galvanostatic charge–discharge (GCD) measurements. The results of scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) revealed the occurrence of sodium deposition after long-time cycling, which caused the reduction in the specific capacitance. This study results suggest that the light-weight GDL, which can help overcome the problem of the oxide layer on metal–foam substrates, is a promising current collector to be used with Ni-based electroactive materials for energy storage applications.     

花状Ni(OH)2微球的制备及其对尿酸的快速检测

采用微波辅助水热法制备了均匀分级的氢氧化镍(Ni(OH)₂)微球,通过X射线衍射(XRD)仪、扫描电子显微镜(SEM)和透射电子显微镜(TEM)对Ni(OH)₂的组成和形貌进行了表征. Ni(OH)₂微球的平均直径约1.6 μm,复杂的花状结构使其具有较大的比表面积.将微球制备成Ni(OH)₂修饰的玻碳电极,并将其用于0.1 mol/L NaOH溶液中尿酸(UA)的检测,该电极具有良好的电催化活性.这种传感器表现出较宽的线性范围(0.1~1.5 mmol/L)和高灵敏度(475.71 μA ·L/(mmol ·cm2)),且有较低的检出限(1.8 μmol/L).利用电化学测试对内源性干扰物进行检验,发现Ni(OH)₂微球修饰电极对UA的选择性较好.结果表明:Ni(OH)₂微球在研发无酶尿酸传感器方面具有重要的应用潜力.     

Sonochemical synthesis of nanostructured nickel hydroxide as an electrode material for improved electrochemical energy storage application

A facile and fast approach for the synthesis of a nanostructured nickel hydroxide(Ni(OH)_2) via sonochemical technique is reported in the present study. The X-ray diffraction results confirmed that the synthesized Ni(OH)_2 was oriented in β-phase of hexagonal brucite structure. The nanostructured Ni(OH)_2 electrode exhibited the maximum specific capacitance of 1256 F/g at a current density of 200 mA/g in 1 M KOH_((aq)). Ni(OH)_2 electrodes exhibited the pseudocapacitive behavior due to the presence of redox reaction. It also exhibited long-term cyclic stability of 85% after 2000 cycles, suggesting that the nanostructured Ni(OH)_2 electrode will play a promising role for high performance supercapacitor application.     

掺杂球形氢氧化镍电化学行为研究

采用循环伏安法研究了Ｎｉ（ＯＨ）２粉末微电极,认为Ｎｉ（ＯＨ）２微电极电化学过程是一个准可逆过程且电极反应在Ｎｉ（ＯＨ）２／ＮｉＯＯＨ之间进行．研究了在阳极过程中掺杂元素对Ｎｉ（ＯＨ）２质子扩散系数的影响,发现掺Ｃｏ后比纯Ｎｉ（ＯＨ）２的扩散系数提高近１倍,而掺Ｚｎ后则扩散系数有所降低．掺Ｃｏ和Ｚｎ后Ｎｉ（ＯＨ）２电极的析氧电位均比纯Ｎｉ（ＯＨ）２的析氧电位有所提高．