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本文报道一种制备β-Co(OH)2/氮掺杂碳石墨烯纳米复合材料(Co(OH)2/C-N@GP)的方法。首先,我们通过在含羧基的聚苯乙烯(PS)乙醇分散体中使Co(NO3)2·6H2O与2-甲基咪唑反应,合成了ZIF-67/聚苯乙烯的复合材料。然后将ZIF-67/聚苯乙烯复合材料高温碳化,同时与硫代乙酰胺和石墨烯反应生成Co(SO4)2/C-N@GP。最后,Co(SO4)2/C-N@GP在KOH水溶液中浸泡以获得Co(OH)2/C-N@GP纳米复合材料。所制备的Co(OH)2/C-N@GP的扫描电镜图显示尺寸为10~20 nm的Co(OH)2很好地分散在石墨烯上。电化学分析表明Co(OH)2/C-N作为超级电容器的电极材料表现出典型的法拉第电荷转移行为,并且当石墨烯存在时,其比电容可显著增强。在2 mol·L-1 KOH中,Co(OH)2/C-N@GP在2 A·g-1下表现出985.4 F·g-1的高比电容,1 000次循环后的比电容保持率为76.6%。 相似文献
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本文报道一种制备β-Co(OH)2/氮掺杂碳石墨烯纳米复合材料(Co(OH)2/C-N@GP)的方法。首先,我们通过在含羧基的聚苯乙烯(PS)乙醇分散体中使Co(NO3)2·6H2O与2-甲基咪唑反应,合成了ZIF-67/聚苯乙烯的复合材料。然后将ZIF-67/聚苯乙烯复合材料高温碳化,同时与硫代乙酰胺和石墨烯反应生成Co(SO4)2/C-N@GP。最后,Co(SO4)2/C-N@GP在KOH水溶液中浸泡以获得 Co(OH)2/C-N@GP 纳米复合材料。所制备的 Co(OH)2/C-N@GP 的扫描电镜图显示尺寸为 10~20 nm 的 Co(OH)2很好地分散在石墨烯上。电化学分析表明Co(OH)2/C-N作为超级电容器的电极材料表现出典型的法拉第电荷转移行为,并且当石墨烯存在时,其比电容可显著增强。在2 mol·L-1 KOH中,Co(OH)2/C-N@GP在2 A·g-1下表现出985.4 F·g-1的高比电容,1 000次循环后的比电容保持率为76.6%。 相似文献
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Cheng-Yue Sun Yun-Guang Zhu Tie-Jun Zhu Jian Xie Gao-Shao Cao Xin-Bing Zhao 《Journal of Solid State Electrochemistry》2013,17(4):1159-1165
A Co(OH)2/graphene sheet-on-sheet hybrid has been fabricated by in situ one-step hydrothermal growth for electrochemical pseudocapacitors application. The hybrid delivers a specific capacitance of 436 F?g?1 at a current density of 50 A?g?1. Besides, it can keep a specific capacitance of 651 F?g?1 after 10,000 cycles at 10 A?g?1. The excellent performance can be ascribed to the high-quality graphene matrix, regular morphology and high crystallinity of Co(OH)2, and unique sheet-on-sheet structure of the hybrid, endowing enhanced transportation of electrons and Faradic redox reactions. The results demonstrate that the Co(OH)2/graphene hybrid with a sheet-on-sheet structure is promising for high-performance energy storage applications. 相似文献
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Herein, we introduce a facile, inexpensive and fast, and additive-/template-free method to fabricate highly stable nickel hydroxide nanofibers for supercapacitor applications. Ni(OH)2 nanofibers were electrodeposited on electro-etched carbon fiber paper by a potential step method (Ni(OH)2-ECFs) and characterized using scanning electron microscopy and X-ray diffraction analysis. Electrochemical performance of Ni(OH)2-ECF was studied in symmetric two-electrode assembly by cyclic voltammetry, galvanostatic charge–discharge method, and electrochemical impedance spectroscopy. A specific capacitance of 277.5 F g?1 was achieved for the symmetric supercapacitor based on two identical Ni(OH)2-ECFs. Our findings demonstrate high-rate capability with excellent stability (approximately 100 % capacitance retention) for Ni(OH)2-ECF supercapacitor, originated from the intimate contact between Ni(OH)2 and ECF. Our studies suggest the Ni(OH)2-ECF electrode as an excellent material for supercapacitor applications. 相似文献
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Ni(OH)(2)/MnO(2) core-shell nanowires with a nanoflake surface have been designed and synthesized, and can be applied not only in neutral electrolytes (355 F g(-1), 70.4 wt% MnO(2)) but are also appropriate for alkaline electrolytes (487.4 F g(-1), 35.5 wt% MnO(2)), with high cycling stability due to the synergistic effect between the core and shell. 相似文献
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以Co(NO_3)_2·6H_2O和Ni(NO_3)_2·6H_2O为钴源和镍源,采用溶剂热法一步合成了Co(OH)_2/Ni(OH)_2复合材料,通过煅烧该复合材料可得到NiCo_2O_4。采用XRD、SEM、BET等对材料进行了表征,结果表明,Co(OH)_2/Ni(OH)_2复合材料是薄片组成的花状形貌,比表面积为37. 48m~2/g。电化学性能测试表明,Co(OH)_2/Ni(OH)_2复合材料比NiCo_2O_4具有更高的比电容值和容量保持率。在0. 5A/g的电流密度下,复合材料比电容值可达到1097. 8F/g,而NiCo_2O_4比电容值仅为86. 1F/g。因此,与煅烧后的NiCo_2O_4材料相比,Co(OH)_2/Ni(OH)_2复合材料具有更加优良的电化学性能,这为高性能超级电容器材料的制备提供了一个新思路。 相似文献
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Gongkai Wang Xiang Sun Fengyuan Lu Qingkai Yu Changsheng Liu Jie Lian 《Journal of solid state chemistry》2012
We report the synthesis of novel MnSn(OH)6/graphene nanocomposites produced by a co-precipitation method and their potential application for electrochemical energy storage. The hydroxide decorated graphene nanocomposites display better performance over pure MnSn(OH)6 nanoparticles because the graphene sheets act as conductive bridges improving the ionic and electronic transport. The crystallinity of MnSn(OH)6 nanoparticles deposited on the surface of graphene sheets also impacts the capacitive properties as electrodes. The maximum capacitance of 31.2 F/g (59.4 F/g based on the mass of MnSn(OH)6 nanoparticles) was achieved for the sample with a low degree of crystallinity. No significant degradation of capacitance occurred after 500 cycles at a current density of 1.5 A/g in 1 M Na2SO4 aqueous solution, indicating an excellent electrochemical stability. The results serve as an example demonstrating the potential of integrating highly conductive graphene networks into binary metal hydroxide in improving the performance of active electrode materials for electrochemical energy storage applications. 相似文献
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Shilei Gong Qing Cao Li′e Jin Cungui Zhong Xiaohua Zhang 《Journal of Solid State Electrochemistry》2016,20(3):619-628
Three-dimensional Ni(OH)2 nanoflakes were prepared via a facile and cost-effective electrodeposition method using commercial activated carbon (AC) as substrate. Nitric acid treatment (NT) and partial crystallization (PC) by metal nickel catalysis were applied for AC. The effects of the oxygen-containing functional groups and the degree of crystallization on the electrochemical performance of the electrode were investigated. The resulting Ni(OH)2/PC–NT–AC/nickel foam electrode exhibits distinct performance with a specific capacitance of 2971 F/g (scaled to the mass of active Ni(OH)2) at a current density of 6 A/g. A high capacitance of 1919 F/g was still achieved even at 40 A/g, which is much higher than Ni(OH)2/AC/nickel foam electrode and Ni(OH)2/NT–AC/nickel foam electrode. The excellent performance of Ni(OH)2/PC–NT–AC/nickel foam electrode can be attributed to the presence of large surface area and highly conductive PC–NT–AC network on nickel foam. This study presents an effective method to improve the dispersion and rate capability of Ni(OH)2 nanostructure electrodes. 相似文献
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通过对模拟电池进行恒流充放电、交流阻抗等测试和析气实验,研究了在亚镍中掺杂氧化钐SmO对镍电极电化学性能的影响。结果表明,掺杂氧化钐SmO的质量分数在1.0%时,镍电极的电化学阻抗变小,提高了镍电极电化学活性、高温性能与充电效率,能够有效抑制充电过程中氧的产生,在室温条件下以0.2C充放电时,掺杂SmO镍电极的放电比容量为138.04 mAh.g-1,比空白镍电极提高了23.01%;50℃下1C充放电时,放电比容量为90.313 mAh.g-1,较未添加氧化钐提高8.69%。 相似文献
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Agnieszka Kapałka Audrey Cally Stefano Neodo Christos Comninellis Michael Wächter Kai M. Udert 《Electrochemistry communications》2010,12(1):18-21
The electrochemical oxidation of ammonia was investigated on a Ni/Ni(OH)2 electrode prepared by potential cycling of a Ni electrode in 1 M NaClO4. It was found that oxidation of ammonia is strongly pH dependent and proceeds mainly at pH values above 7. This indicates that NH3 rather than is oxidized on nickel electrodes. Oxidation of ammonia occurs in the potential region of Ni(II)/Ni(III) redox activity resulting in formation of a clear peak. Ni/Ni(OH)2 is not deactivated during ammonia oxidation even at high ammonia concentrations. A considerable fraction of the ammonia was oxidized to nitrate (11%), while the rest were gaseous nitrogen compounds. It is postulated that nitrogen was formed via a mechanism involving direct electron transfer from ammonia to the anode whereas the formation of nitrate involved oxygen transfer from water to an ammonia molecule. 相似文献
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Jun Zhang Lingzhi Shangguan Shaomin Shuang Chuan Dong 《Russian Journal of Electrochemistry》2013,49(9):888-894
A nickel hydroxide-modified nickel electrode (Ni(OH)2/Ni) was successfully prepared by the cyclic voltammetry (CV) method and the electrocatalytic properties of the electrode for formaldehyde and methanol oxidation have been investigated respectively. The Ni(OH)2/Ni electrode exhibits high electrocatalytic activity in the reaction. A new method has been developed for formaldehyde determination at the nickel hydroxide-modified nickel electrode and the experimental parameters were optimized. The oxidation peak current is linearly proportional to the concentration of formaldehyde in the range of 7.0 × 10?5 to 1.6 × 10?2 M with a detection limit of 2.0 × 10?5 M. Recoveries of artificial samples are between 93.3 and 103.5%. The effect of scan rate and methanol concentration on the electrochemical behavior of methanol were investigated respectively. 相似文献
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Ming Hao Yi Chen Weilai Xiong Liu Zhang Liyang Wu Yang Fu Tao Mei Jianying Wang Jinhua Li Xianbao Wang 《Journal of Solid State Electrochemistry》2016,20(3):665-671
Crosslinked-polyaniline (CPA) nano-pillar arrays adsorbed on the surface of reduced graphene oxide (RGO) sheets were synthesized by in situ solution polymerization through two steps of reduction. The electrochemical analyses demonstrated that the befittingly reduced CPA/RGO composite exhibited high performance as electrode materials for supercapacitors. The CPA/RGO composite showed very high specific capacitance of 1532 F g?1 at a scan rate of 10 mV s?1 or 694 F g?1 at a current density of 2 A g?1 in 1 M H2SO4 electrolyte, as well as great energy density of 61.4 W h kg?1 at a current density of 2 A g?1. The electrode material also had decent power density of 4 kW kg?1 at a current density of 10 A g?1, and good cycling stability of 92.5 % capacitance retained after 500 cycles of cyclic voltammetry at 500 mV s?1. The neat microstructures and super electrochemical properties suggest the potential use of the composites in supercapacitors. 相似文献
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Hoda Nourmohammadi Miankushki Arman Sedghi Saeid Baghshahi 《Journal of Solid State Electrochemistry》2018,22(11):3317-3329
In this study, to improve the specific capacitance of graphene-based supercapacitor, novel quadri composite of G/PPy/MnOx/Cu(OH)2 was synthesized by using a facile and inexpensive route. First, a two-step method consisting of thermal decomposition and in situ oxidative polymerization was employed to fabricate graphene/polypyrrole/manganese oxide composites. Second, Cu(OH)2 nanowires were deposited on Cu foil. Afterwards, for the electrochemical measurements, composite powders were deposited on Cu(OH)2/Cu foil substrate as working electrodes. The synthesized samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FT-IR) spectroscopy, and Raman spectroscopy. The XRD analysis revealed the formation of PPy/graphene, Mn3O4/graphene, and graphene/polypyrrole/MnOx. In addition, the presence of polypyrrole and manganese oxides was confirmed using FT-IR and Raman spectroscopies. Graphene/polypyrrole/MnOx/Cu(OH)2 electrode showed the best electrochemical performance and exhibited the largest specific capacitance of approximately 370 F/g at the scan rate of 10 mV/s in 6 M KOH electrolyte. In addition, other electrochemical measurements (charge–discharge, EIS and cyclical performance) of the G/Cu(OH)2, G/PPy/Cu(OH)2, G/Mn3O4/Cu(OH)2, and G/PPy/MnOx/Cu(OH)2 electrodes suggested that the G/PPy/MnOx/Cu(OH)2 composite electrode is promising materials for supercapacitor application. 相似文献