有序介孔碳负载NiCo2O4电极的制备及其超电容性能

以有序介孔碳(OMC)为载体,采用共沉淀法制备了OMC/NiCo2O4复合物.用X射线衍射(XRD)、傅里叶变换红外(FT-IR)光谱和透射电镜(TEM)研究其结构与形貌,发现NiCo2O4纳米颗粒均匀地负载在有序介孔碳上.循环伏安和恒流充放电测试表明,NiCo2O4质量分数为40%时,在1A·g-1的电流密度下,复合物电极的比电容可以达到577.0F·g-1,电流密度为8A·g-1时,比电容可以达到470.8F·g-1,并具有良好的循环稳定性.在2A·g-1的电流密度下,经过2000次循环后,比电容还可达到508.4F·g-1,电容保持率为92.7%.     

泡沫镍负载的NiCo2O4纳米线阵列电极的超级电容性能

采用无模板自然生长法制备了泡沫镍支撑的NiCo₂O₄纳米线阵列电极, 利用扫描电镜(SEM)和透射电镜(TEM)观测了纳米线的表面形貌, 利用X射线衍射(XRD)分析了纳米线的结构, 通过循环伏安、恒流充放电和交流阻抗测试了电极的超级电容性能. 结果表明: NiCo₂O₄纳米线直径约为500-1000 nm、长度约为10 μm, 垂直且密集地生长在泡沫镍骨架上. 纳米线阵列电极的放电比容量高达741 F·g^-1, 循环420次后比容量仍保持在655 F·g^-1, 电化学阻抗测试其电荷传递电阻仅为0.33 Ω, 420次循环后电荷传递电阻仅增加0.06 Ω.     

SnO_2/石墨纳米片复合电极及其在超级电容器中的应用

在电场的作用下对石墨棒进行电化学剥离,使其表面形成相互平行排列,且垂直于石墨棒基底的二维(2D)石墨纳米片阵列(GNSA).然后通过阴极还原电沉积法制备Sn O2/石墨纳米片阵列(Sn O2/GNSA)复合电极.采用场发射扫描电镜(FE-SEM)、X射线衍射(XRD)和傅里叶变换红外(FT-IR)光谱对其形貌和结构进行了表征.电化学测试表明该复合电极具有优异的超电容性能,在0.5 mol·L-1Li NO3电解质中,扫描速率为5 m V·s-1,电位窗口为1.4 V时,比电容达4015 F·m-2.由Sn O2/GNSA复合电极和相同电解质组装成的对称型超级电容器,在扫描速率为5 m V·s-1时,其电位窗口可增至1.8 V,能量密度达到0.41 Wh·m-2,循环5000圈后其比电容仍保持为初始比电容的81%.     

SnO2/石墨纳米片复合电极及其在超级电容器中的应用

在电场的作用下对石墨棒进行电化学剥离, 使其表面形成相互平行排列, 且垂直于石墨棒基底的二维(2D)石墨纳米片阵列(GNSA). 然后通过阴极还原电沉积法制备SnO₂/石墨纳米片阵列(SnO₂/GNSA)复合电极.采用场发射扫描电镜(FE-SEM)、X射线衍射(XRD)和傅里叶变换红外(FT-IR)光谱对其形貌和结构进行了表征.电化学测试表明该复合电极具有优异的超电容性能, 在0.5 mol·L^-1 LiNO₃电解质中, 扫描速率为5 mV·s^-1, 电位窗口为1.4 V时, 比电容达4015 F·m^-2. 由SnO₂/GNSA复合电极和相同电解质组装成的对称型超级电容器, 在扫描速率为5 mV·s^-1时, 其电位窗口可增至1.8 V, 能量密度达到0.41 Wh·m^-2, 循环5000 圈后其比电容仍保持为初始比电容的81%.     

超级电容器电极材料MnO_2纳米棒的制备及其电化学性能(英文)

以洋葱碳为还原剂,KMnO4为氧化剂,稀硫酸溶液为溶剂,采用水热法一步制备MnO2纳米棒.利用X射线衍射仪和透射电子显微镜分析了MnO2纳米棒的物相、结构、形貌;将MnO2纳米棒作为电极材料组装了超级电容器,采用电池测试系统测定了超级电容器的电化学性能.结果表明,所得到的产物为α-MnO2,其直径为5~10nm,长度为50~100nm;以MnO2纳米棒作为电极材料组装的超级电容器具有较高的比容量和稳定性,有望在超级电容器的研究和应用中得到推广.     

超薄Co3O4纳米片薄膜制备及其电化学传感器性能

本文以电沉积的金属钴薄膜作为原材料,通过简单的氧化技术获得了薄膜前驱体材料,并进一步在350 ^oC热处理条件下获得了超薄Co₃O₄纳米片薄膜材料. 通过扫描电镜（SEM）,X-射线衍射（XRD）,透射电镜（TEM）等手段对材料的物理结构进行了深入分析,并通过循环伏安法（CV）表征了该薄膜材料的电化学活性. 作为电化学传感器件的活性材料,该薄膜材料对H₂O₂的检测表现出较宽的线性浓度检测范围（0 ~ 4 mmol•L^-1）和较高的电流响应(~ 1.15 mA•cm^-2),在该领域具有较高的应用价值.     

用尖晶石型化合物NiCo2O4和复合镀技术制备析氧电极

为减少析氧电位、提高电极的稳定性、降低能耗和成本，人们一直在努力合成各种过渡金属复合氧化物作为析氧的电催化材料［１］．研究表明，尖晶石型化合物ＮｉＣｏ２Ｏ４对氧的析出有较高的催化活性［２］．但因其制备方法多为喷涂热解法，需４００℃以上温度，因此易发生...     

水热法制备Bi2O3纳米片及其电化学性能的研究

以Bi(NO₃)₃和氨水为原料、水溶性淀粉为分散剂, 采用水热法制备了Bi₂O₃纳米片, 用X射线衍射(XRD)、扫描电子显微技术(SEM)和氮气吸附-脱附等对材料进行了表征. 结果表明Bi₂O₃纳米片厚度分布比较窄, 比表面积达到9.26 m²/g. 同时, 采用循环伏安法和充放电仪测试了Bi₂O₃纳米片的电化学性能, 结果显示其具有一定的电化学活性.     

Heterostructural NiCo2O4 Nanocomposites for Nonenzymatic Electrochemical Glucose Sensing

Hierarchical nanocomposites consisting of NiCo₂O₄ nanorods and NiCo₂O₄ nanoparticles through a straightforward two-step hydrothermal process was employed as a working electrode to examine the electrochemical behavior of glucose. The NiCo₂O₄@NiCo₂O₄ heterostructures was confirmed by the scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffractometer (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemistry analysis. Results indicated that glucose is electrochemically oxidized with improved sensitivity at the NiCo₂O₄@NiCo₂O₄ sensor, compared to NiCo₂O₄ sensors. Analytical parameters such as the optimal potential (0.45 V), linear range from 0.4 μM to 5.2 mM, limit of detection (1.1 μΜ) (S/N=3), stability and repeatability (2.7 %) demonstrate the suitability of the prepared sensor for glucose analysis. Moreover, the proposed sensor could be used for actual samples analysis in complex matrices.     

以泡沫镍载NiCo2O4纳米线阵列为阴极催化剂的Al-H2O2半燃料电池

研究了以泡沫镍载NiCo2O4纳米线阵列为阴极催化剂的Al-H2O2半燃料电池的性能. 以无模板生长法制备了泡沫镍载NiCo2O4纳米线阵列阴极材料, SEM测定结果表明, NiCo2O4纳米线几乎垂直于泡沫镍载体表面生长. 以电压和功率密度-电流密度曲线研究了H2O2浓度、电解液流速和温度对电池性能的影响, 结果显示, 以铝片为阳极, 0.6 mol/L H2O2为氧化剂的电池的开路电压约为1.40 V; 在室温和57 ℃下, 电流密度为98和172 mA/cm2时, 最大功率密度分别达到79和120 mW/cm2.  在5000 s的测试时间内, 0.70 V的恒电流密度和75 mA/cm2 的恒电压值几乎为一常数, 这表明以泡沫镍载NiCo2O4纳米线阵列为催化剂电还原H2O2具有很好的活性、稳定性和传质性能.     

Porous NiCo2O4 Nanowire Arrays as Supercapacitor Electrode Materials with Extremely High Cycling Stability

In this work, NiCo₂O₄(NCO) was synthesized via microwave hydrothermal method and a further annea- ling treatment. Research results have shown that the surface defects(Co²⁺ site) and pore size of the materials can be adjusted by simply changing the calcination temperatures, and porous nanowire arrays structure can be obtained. The porous structure is conducive to the penetration of the electrolyte and enables the NCO to fully participate in the electrochemical reaction. What's more, the NCO material has ample space to buffer the volume change in the cycle test, improving the cycling stability. The NCO obtained at 350℃ has better performance. It exhibits a specific capacitance of 648.69 F/g at 1 A/g and good rate capability. Especially, at 10 A/g, the specific capacitance can still be maintained at 80.00% after 10000 galvanostatic charge/discharge(GCD) cycles, showing excellent cycling stability.     

A Microwave Synthesis of Mesoporous NiCo2O4 Nanosheets as Electrode Materials for Lithium‐Ion Batteries and Supercapacitors

A facile microwave method was employed to synthesize NiCo₂O₄ nanosheets as electrode materials for lithium‐ion batteries and supercapacitors. The structure and morphology of the materials were characterized by X‐ray diffraction, field‐emission scanning electron microscopy, transmission electron microscopy and Brunauer–Emmett–Teller methods. Owing to the porous nanosheet structure, the NiCo₂O₄ electrodes exhibited a high reversible capacity of 891 mA h g^?1 at a current density of 100 mA g^?1, good rate capability and stable cycling performance. When used as electrode materials for supercapacitors, NiCo₂O₄ nanosheets demonstrated a specific capacitance of 400 F g^?1 at a current density of 20 A g^?1 and superior cycling stability over 5000 cycles. The excellent electrochemical performance could be ascribed to the thin porous structure of the nanosheets, which provides a high specific surface area to increase the electrode–electrolyte contact area and facilitate rapid ion transport.     

NiCo2O4/MXene Hybrid as an Efficient Bifunctional Electrocatalyst for Oxygen Evolution and Reduction Reaction

For the advancement of electrochemical energy conversion and storage technologies, bifunctional electrocatalysts are crucial for efficiently driving both the oxygen evolution (OER) and reduction reactions (ORR). Cobalt-based spinel oxides are a class of promising bifunctional electrocatalysts. However their low electrical conductivity and stability may hinder further improvement. A novel composite material composed of NiCo₂O₄ nanoparticles integrated with emerging two dimensional MXene nanosheets (NiCo₂O₄/MXene) was developed. The successful integration of NiCo₂O₄ with MXene brings about a number of attractive structural features. This includes synergistic effects between NiCo₂O₄ and MXene, highly accessible surface areas, complete exposure of numerous active sites, and excellent electronic conductivity, all of which collectively contribute to the desirability of composite material for OER and ORR. The synthesized NiCo₂O₄/MXene composite showed extraordinary OER electrocatalytic activity with a lower overpotential of 360 mV at a current density of 10 mA/cm², and a small Tafel slope of 64 mV/dec compared to NiCo₂O₄, MXene and NiCo₂O₄+MXene (physically mixed). Additionally, NiCo₂O₄/MXene displays an ORR limiting current density of −4 mA/cm² and exhibited highest onset potential and half wave potential of 0.92 V and 0.72 V vs. RHE, respectively, for the ORR in alkaline media compared to NiCo₂O₄, MXene and NiCo₂O₄+MXene (physically mixed).     

NiCo_2O_4@C纳米复合材料的水热合成及电化学储锂性能

采用一步水热法合成了棒状NiCo_2O_4前驱体,并通过调节水热反应过程中碳源(葡萄糖)的加入量以及后续热处理条件(气氛、温度)得到了一系列不同的NiCo_2O_4及NiCo_2O_4@C产物,并对这些产物的结构、形貌及电化学储锂性能进行了测试.结果表明,适当的葡萄糖加入量(0.5 g)配合合理的煅烧条件(400℃,氮气气氛)可以获得倍率性能和循环稳定性兼具的NiCo_2O_4@C纳米复合材料.在100 m A/g的电流密度下,该材料的首次充/放电比容量为634.1/767.2 m A·h/g,对应的库仑效率为82.7%,5周后的放电比容量为650.1 m A·h/g,容量保持率为84.74%,且在300 m A/g的高电流密度下可逆比容量仍可保持在225.9m A·h/g.     

NiCo2O4纳米线对 H2O2电还原的催化性能

以无模板生长法制备了泡沫镍载NiCo2O4纳米线正极材料, XRD和SEM表征结果表明, 所得材料为NiCo2O4纳米线, 以循环伏安法和计时电流法研究了泡沫镍载NiCo2O4纳米线对H2O2电还原的催化性能. 结果显示, 在0.4 mol/L H2O2 和 3.0 mol/L NaOH 溶液中, 当电压为-0.4 V(vs. Ag/AgCl)时, 循环伏安的电流密度达到125 mA/cm2; 当电压为-0.2, -0.3和 -0.4 V 时, 在30 min 的测试时间内, 计时电流密度几乎均为一常数, 表明以泡沫镍载NiCo2O4纳米线为催化剂电还原H2O2具有很高的活性和很好的稳定性.     

NiCo_2S_4六角片作为钠离子电池负极材料的电化学性能及储钠动力学

通过共沉淀以及后续的气相硫化成功制备了横向边长约为2μm,纵向厚度约为30 nm的NiCo_2S_4六角片,并研究了其作为钠离子电池负极材料的电化学性能。电化学性能测试结果显示在1000 mA·g~(-1)的电流密度下,NiCo_2S_4电极循环60次后仍然可保持约387mAh·g~(-1)的可逆比容量。此外,NiCo_2S_4电极还具有良好的倍率性能,在200、400、800、1000和2000mA·g~(-1)的电流密度下,容量分别为542、398、347、300和217mAh·g~(-1)。通过进一步动力学机制分析发现,NiCo_2S_4电极的良好的倍率性能得益于其二维片层状结构诱导产生的赝电容。上述结果表明,NiCo_2S_4纳米六角片是一种极具潜力的钠离子电池负极材料。