共查询到17条相似文献,搜索用时 78 毫秒
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《应用化工》2022,(12)
以FeCl_3·6H_2O和FeCl_2·4H_2O为铁源,以Na OH溶液为沉淀剂,选择共沉淀法制备Fe_3O_4∕石墨烯复合物。以Fe(2+)和Fe(2+)和Fe(3+)的浓度作为变量制得5种不同比例的Fe_3O_4/石墨烯纳米复合材料,然后将所得复合材料压制成电极片,组装成超级电容器后进行循环伏安(CV)、恒电流充放电(GCD)、交流阻抗(EIS)测试,探究Fe_3O_4与石墨烯的含量比对复合材料电化学性能的影响。结果表明,当FeCl_3·4H_2O和FeCl_2·4H_2O用量分别为0.456 g和0.665 g,氧化石墨烯用量为150 mg时,所制备复合材料的电化学性能最佳,比电容可达510 F/g。 相似文献
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叙述了以液相共沉淀法制备纳米磁性Fe3O4粒子的工艺,研究了反应搅拌速度、n(Fe3+)/n(Fe2+)的比例、pH值和熟化温度对制备纳米Fe3O4粒子的影响,并利用透射电镜表征观察Fe3O4纳米粒子的形貌。研究结果表明,在搅拌速度较快的情况下制备纳米级Fe3O4颗粒的最佳合成工艺条件为:n(Fe3+)/n(Fe2+)为1.8∶1(摩尔比),熟化温度70℃,熟化时间30 min,以氨水作沉淀剂最佳pH值是9左右,可制得纯度较高,粒径小于10 nmFe3O4磁性粒子。 相似文献
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纳米光催化剂TiO_2/Fe_3O_4的制备及表征 总被引:2,自引:3,他引:2
采用两步法制备磁性负载纳米光催化剂TiO2/Fe3O4。首先用液相共沉淀法制备磁性纳米Fe3O4颗粒;然后用溶胶-凝胶法,以钛酸四正丁酯为先驱体,通过水解缩聚在Fe3O4纳米颗粒表面包覆TiO2层,得到易于磁分离回收的复合纳米光催化剂TiO2/Fe3O4,粒径大约为30 nm。利用TEM、XRD、FT-IR、VSM对Fe3O4和TiO2/Fe3O4的结构和性能进行了表征,结果表明,制备的Fe3O4为面心立方晶体(FCC)结构,具有超顺磁性;TiO2为锐钛矿相,包覆在Fe3O4的表面,形成了核-壳式结构的TiO2/Fe3O4复合光催化剂。 相似文献
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以苯胺和氧化石墨烯溶液为原料,采用乳液聚合法,根据m(氧化石墨烯)∶m(苯胺)为0∶10、1∶20和1∶10合成不同石墨烯/聚苯胺复合材料。采用紫外可见分光光度计、SEM、XRD及FT-IR对复合材料进行表征。XDR和FT-IR表明,乳液聚合合成了石墨烯/聚苯胺复合材料。SEM表明,聚苯胺以氧化石墨烯为载体,分散在其表面。光催化结果表明,石墨烯/聚苯胺复合材料的光催化性能较纯聚苯胺明显提高,m(氧化石墨烯)∶m(苯胺)=1∶20的石墨烯/聚苯胺复合材料的光催化性能高于m(氧化石墨烯)∶m(苯胺)=1∶10,原因可能在于微观结构的不同。 相似文献
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In this work, C-graphene composed of core graphene and carbon shells was prepared to obtain a new type of carbon electrode materials. Carbon shells containing nitrogen groups were prepared by coating polyaniline (PANI) onto graphene by in situ polymerization and subsequent carbonization at 850 °C. After carbonization, the C-graphene contained 6.5% nitrogen and showed a 2D plate structure and crystallinity like that of pristine graphene. In addition, the C-graphene exhibited electrochemical performance superior to that of pristine graphene, and the highest specific capacitance (170 F/g) of the C-graphene was obtained at a scan rate of 0.1 A/g, as compared to 138 F/g for pristine graphene. This superior performance was attributed to the synergistic effect of porous carbon layer and the graphene and the pseudocapacitive effect by the nitrogen groups formed on the carbon electrode after carbonization. 相似文献
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《Carbon》2013
Reduced graphene oxide (rGO) tethered with maghemite (γ-Fe2O3) was synthesized using a novel modified sol–gel process, where sodium dodecylbenzenesulfonate was introduced into the suspension to prevent the undesirable formation of an iron oxide 3D network. Thus, nearly monodispersed and homogeneously distributed γ-Fe2O3 magnetic nanoparticles could be obtained on surface of graphene sheets. The utilized thermal treatment process did not require a reducing agent for reduction of graphene oxide. The morphology and structure of the composites were investigated using various characterization techniques. As-prepared rGO/Fe2O3 composites were utilized as anodes for half lithium ion cells. The 40 wt.%-rGO/Fe2O3 composite exhibited high reversible capacity of 690 mA h g−1 at current density of 500 mA g−1 and good stability for over 100 cycles, in contrast with that of the pure-Fe2O3 nanoparticles which demonstrated rapid degradation to 224 mA h g−1 after 50 cycles. Furthermore, the composite showed good rate capability of 280 mA h g−1 at 10C (∼10,000 mA g−1). These characteristics could be mainly attributed to both the use of an effective binder, poly(acrylic acid) (PAA), and the specific hybrid structures that prevent agglomeration of nanoparticles and provide buffering spaces needed for volume changes of nanoparticles during insertion/extraction of Li ions. 相似文献
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A new route to synthesize polyaniline (PANI)-grafted carboxyl-functionalized graphene (PGCG) composite material is established. In this paper, PGCG is first prepared through a two-step carboxyl-functionalized process. PANI can be grafted and grown on the surface of graphene due to the covalent bonding existing between the carboxyl-functionalized graphene and polyaniline. This method cannot only improve the mechanical performance and adaptive performance of polyaniline effectively, but also reduce the production costs and environmental pollution during the synthetic process. Therefore, a green and industrial synthetic process is achieved. X-ray diffraction (XRD) patterns, X-ray photoelectron spectroscopy (XPS) and Fourier transformed infrared (FTIR) all confirm that composite materials have been prepared successfully. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicate that the as-prepared PGCG has regular structure. Thermogravimetric analysis (TGA) indicates that the addition of graphene nanosheets can significantly improve the thermostability of PANI. Moreover, the as-prepared material exhibits superior electrochemical performance. As an electrode material for supercapacitors, PGCG possesses high specific capacitance of 158 F g?1 at a scan rate of 25 mV s?1 and 147 F g?1 at 50 mV s?1 in 1 M H2SO4. The Nyquist plot also confirms that the PGCG has low charge transfer resistance and good capacitive behavior. These great properties make PGCG a novel electrode material with potential applications in high-performance energy storage devices. 相似文献
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利用热解还原将Hummers法制得的氧化石墨烯还原为石墨烯,并采用化学沉淀法将纳米硫成功负载到石墨烯片层上,获得石墨烯/纳米硫(RGO/nano-S)正极复合材料。利用FT-IR、XRD、SEM、TEM和Raman对所制备复合材料的微观结构、形貌等进行表征,采用恒流充放电、循环伏安法和交流阻抗法对复合材料的电化学性能进行研究。研究结果表明,热还原所得石墨烯褶皱的表面形成容纳硫及多硫离子的空间,有助于缓解活性物质溶解和抑制多硫离子迁移;同时,均匀分布的纳米硫能更好地与电解液接触,在石墨烯的导电网络上增大了电化学反应面积,进而改善了该材料作为锂硫电池的实际放比电容量和倍率循环性能。 相似文献
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分析了目前石墨烯和聚吡咯(PPy)用作电极材料的不足,详细介绍了近年来超级电容器用石墨烯/PPy复合电极材料的研究进展,指出石墨烯/PPy复合材料在能量转换和存储领域的未来发展方向. 相似文献