共查询到20条相似文献,搜索用时 31 毫秒
1.
Li Li Zhongai Hu Yuying Yang Pengju Liang Ailian Lu Huan Xu Yingying Hu Hongying Wu 《中国化学》2013,31(10):1290-1298
In the present work Mn3O4/reduced graphene oxide hydrogel (Mn3O4-rGOH) with three dimensional (3D) networks was fabricated by a hydrothermal self-assembly route. The morphology, composition, and microstructure of the as-obtained samples were characterized using powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetry analysis (TG), atomic absorption spectrometry (AAS), field emission scanning electron microscopy (FESEM) and transmission electron microscope (TEM). Moreover, the electrochemical behaviors were evaluated by cyclic voltammogram (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS). The test results indicated that the hydrogel with 6.9% Mn3O4 achieved specific capacitance of 148 F.g^-1 at a specific current of 1 A.g^-1, and showed excellent cycling stabilily with no decay after 1200 cycles. In addition, its specific capacitance could retain 70% even at 20 A.g^- 1 in comparison with that at 1 A.g ^-1 and the operating window was up to 1.8 V in a neutral electrolyte. 相似文献
2.
Fluorine‐Doped Fe2O3 as High Energy Density Electroactive Material for Hybrid Supercapacitor Applications 下载免费PDF全文
Dr. Kaliyappan Karthikeyan Samuthirapandian Amaresh Sol Nip Lee Dr. Vanchiappan Aravindan Prof. Yun Sung Lee 《化学:亚洲杂志》2014,9(3):852-857
Nanostructured α‐Fe2O3 with and without fluorine substitution were successfully obtained by a green route, that is, microwave irradiation. The hematite phase materials were evaluated as a high‐performance electrode material in a hybrid supercapacitor configuration along with activated carbon (AC). The presence of fluorine was confirmed through X‐ray photoelectron spectroscopy and transmission electron microscopy. Fluorine‐doped Fe2O3 (F‐Fe2O3) exhibits an enhanced pseudocapacitive performance compared to that of the bare hematite phase. The F‐Fe2O3/AC cell delivered a specific capacitance of 71 F g?1 at a current density of 2.25 A g?1 and retained approximately 90 % of its initial capacitance after 15 000 cycles. Furthermore, the F‐Fe2O3/AC cell showed a very high energy density of about 28 W h kg?1 compared to bare hematite phase (~9 W h kg?1). These data clearly reveal that the electrochemical performance of Fe2O3 can be improved by fluorine doping, thereby dramatically improving the energy density of the system. 相似文献
3.
Jane Cathleen Gabunada Mohanraj Vinothkannan Dong Hee Kim Ae Rhan Kim Dong Jin Yoo 《Electroanalysis》2019,31(8):1507-1516
In this study, magnetite nanorods stabilized on polyaniline/reduced graphene oxide (Fe3O4@PANI/rGO) was synthesized via a wet‐reflux strategy. The possible formation of Fe3O4@PANI/rGO was morphologically and structurally verified by field emission scanning electron microscopy (FE‐SEM), Fourier transform infrared (FT‐IR) spectroscopy, Raman spectroscopy, X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS). Furthermore, the thermal stability of Fe3O4@PANI/rGO was measured by a thermogravimetric analyzer (TGA); the composite had good thermal stability owing to the ceramic nature of Fe3O4. The Fe3O4@PANI/rGO has been applied as a potential sensing platform for electrochemical detection of hydrogen peroxide (H2O2). By the combined efforts of extended active surface area, active carbon support, more catalytic active sites and high electrical conductivity, the Fe3O4@PANI/rGO exhibited an improved performance toward the non‐enzymatic detection of H2O2 in 0.5 M KOH with a fast response time (5 s), high sensitivity (223.7 μA mM?1 cm?2), low limit of detection (4.45 μM) and wide linear range (100 μM–1.5 mM). Furthermore, the fabricated sensor exhibited excellent recovery rates (94.2–104.0 %) during real sample analysis. 相似文献
4.
Li4Ti5O12 (LTO) nanoparticles were prepared by gel‐hydrothermal process and subsequent calcination treatment. Calcination treatment led to structural water removal, decomposition of organics and primary formation of LTO. The formation temperature of spinel LTO nanoparticles was lower than that of bulk materials counterpart prepared by solid‐state reaction or by sol‐gel processing. Based on the thermal gravimetric analysis (TG) and differential thermal gravimetric (DTG), samples calcined at different temperatures (350, 500 and 700°C) were characterized by X‐ray diffraction (XRD), field emitting scanning electron microscopy (FESEM), transmission electron microscopy (TEM), cyclic voltammogram and charge‐discharge cycling tests. A phase transition during the calcination process was observed from the XRD patterns. And the sample calcined at 500°C had a distribution of diameters around 20 nm and exhibited large capacity and good high rate capability. The well reversible cyclic voltammetric results of both electrodes indicated enhanced electrochemical kinetics for lithium insertion. It was found that the Li4Ti5O12 anode material prepared through gel‐hydrothermal process, when being cycled at 8 C, could preserve 76.6% of the capacity at 0.3 C. Meanwhile, the discharge capacity can reach up to 160.3 mAh·g?1 even after 100 cycles at 1 C, close to the theoretical capacity of 175 mAh·g?1. The gel‐hydrothermal method seemed to be a promising method to synthesize LTO nanoparticles with good application in lithium ion batteries and electrochemical cells. 相似文献
5.
6.
Dr. Ganganagappa Nagaraju 《无机化学与普通化学杂志》2012,638(14):2286-2291
A simple low temperature hydrothermal method was found to yield Na0.28V2O5 nanobelts after two days at 130 °C in acidic medium (H2SO4) without using any surfactant. The obtained products were characterized by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR), and Raman spectroscopy. Their morphology was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Additionally, their electrochemical behavior in a lithium battery was investigated. The XRD pattern shows that the product is composed of monoclinic Na0.28V2O5 nanobelts. From the FTIR spectrum, the band centered at 961 cm–1 is assigned to V=O stretching vibration, which is sensitive to intercalation and suggests that Na+ ions are inserted between the vanadium oxide layers. SEM/TEM analyses reveal that the products consist of a large quantity of nanobelts which have a thickness of 60–150 nm and a length of several tens of micrometers. The electrochemical results show that the nanobelts exhibit an initial discharge specific capacity of 390 mAh · g–1, and its stabilized capacity still remained around 200 mAh · g–1 after the 18th cycle. 相似文献
7.
Fan Bai Xinhao Zhang Xinmei Hou Huijuan Liu Junhong Chen Tao Yang 《Electroanalysis》2019,31(8):1448-1457
Amino‐functionalized Fe3O4@carbon microspheres (NH2?Fe3O4@C) were prepared and the electrochemical sensor was constructed using NH2?Fe3O4@C modified glassy carbon electrodes (GCE) to determine toxic heavy metals in aqueous solution. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the structure and phase of NH2?Fe3O4@C. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) results indicate that NH2?Fe3O4@C modified GCE possesses large active area and excellent electron transfer. Under optimized electrochemical condition, Cd(II), Pb(II) and Cu(II) were determined using NH2?Fe3O4@C modified GCE. The electrode through amino functionalization exhibits higher sensitivity and lower detection limit toward Cd(II) and Cu(II) due to the acid‐base pairing interaction between the electron‐rich ?NH2 ligand and the electron‐deficient heavy metal ions. Compared with other similar results reported in the literature, the NH2?Fe3O4@C modified electrode exhibits wider linear response range while with comparable lower detection limit. It also exhibits excellent stability, reproducibility and anti‐interference ability. 相似文献
8.
High Performance Full Sodium‐Ion Cell Based on a Nanostructured Transition Metal Oxide as Negative Electrode 下载免费PDF全文
Dr. María C. López Dr. María J. Aragón Dr. Gregorio F. Ortiz Dr. Pedro Lavela Dr. Ricardo Alcántara Prof. José L. Tirado 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(42):14879-14885
A novel design of a sodium‐ion cell is proposed based on the use of nanocrystalline thin films composed of transition metal oxides. X‐ray diffraction, Raman spectroscopy and electron microscopy were helpful techniques to unveil the microstructural properties of the pristine nanostructured electrodes. Thus, Raman spectroscopy revealed the presence of amorphous NiO, α‐Fe2O3 (hematite) and γ‐Fe2O3 (maghemite). Also, this technique allowed the calculation of an average particle size of 23.4 Å in the amorphous carbon phase in situ generated on the positive electrode. The full sodium‐ion cell performed with a reversible capacity of 100 mA h g?1 at C/2 with an output voltage of about 1.8 V, corresponding to a specific energy density of about 180 W h kg?1. These promising electrochemical performances allow these transition metal thin films obtained by electrochemical deposition to be envisaged as serious competitors for future negative electrodes in sodium‐ion batteries. 相似文献
9.
Equilibrium and kinetic study of novel methyltrimethoxysilane magnetic titanium dioxide nanocomposite for methylene blue adsorption from aqueous media 下载免费PDF全文
Parvin Alizadeh Eslami Mohammad Afzal Kamboh Hamid Rashidi Nodeh Wan Aini Wan Ibrahim 《应用有机金属化学》2018,32(6)
Novel magnetic titanium dioxide nanoparticles decorated with methyltrimethoxysilane (Fe3O4@TiO2‐MTMOS) were successfully fabricated via a sol–gel method at room temperature. The synthesized material was characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, thermogravimetric analysis and vibrating sample magnetometry. The removal efficiency of the adsorbent was evaluated through the adsorption of methylene blue (MB) dye from water samples. The adsorption isotherm and kinetics were evaluated using various models. The Langmuir model indicated a high adsorption capacity (11.5 mg g?1) of Fe3O4@TiO2‐MTMOS. The nanocomposite exhibited high removal efficiency (96%) and good regeneration (10 times) compared to Fe3O4 and Fe3O4@TiO2 at pH = 9.0. Based on the adsorption mechanism, electrostatic interaction plays a main role in adsorption since MB dye is cationic in nature at pH = 9, whereas the adsorbent acquired an anionic nature. The newly synthesized Fe3O4@TiO2‐MTMOS can be used as a promising material for efficient removal of MB dye from aqueous media. 相似文献
10.
Synthesis of Ag Nanoparticle Doped MnO2/GO Nanocomposites at a Gas/Liquid Interface and its Application in H2O2 Detection 下载免费PDF全文
Ag/MnO2/GO nanocomposites were synthesized via the method of gas/liquid interface based on silver mirror reaction, and a non‐enzymatic H2O2 sensor was fabricated through immobilizing Ag/MnO2/GO nanocomposites on GCE. The composition and morphology of the nanocomposites were studied by energy‐dispersive X‐ray spectroscopy (EDS), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Electrochemical investigation indicated that it exhibited a favorable performance for the H2O2 detection. Its linear detection range was from 3 μM to 7 mM with a correlation coefficient of 0.9960; the sensitivity was 105.40 μA mM?1 cm?2 and the detection limit was estimated to be 0.7 μM at a signal‐to‐noise ratio of 3. 相似文献
11.
Synergistic Ternary Composite (Carbon/Fe3O4@Graphene) with Hollow Microspherical and Robust Structure for Li‐Ion Storage 下载免费PDF全文
Xingxing Li Xueying Zheng Prof. Jie Shao Tian Gao Qiang Shi Prof. Dr. Qunting Qu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(1):376-381
The electrode materials with hollow structure and/or graphene coating are expected to exhibit outstanding electrochemical performances in energy‐storage systems. 2D graphene‐wrapped hollow C/Fe3O4 microspheres are rationally designed and fabricated by a novel facile and scalable strategy. The core@double‐shell structure SPS@FeOOH@GO (SPS: sulfonated polystyrene, GO: graphene oxide) microspheres are first prepared through a simple one‐pot approach and then transformed into C/Fe3O4@G (G: graphene) after calcination at 500 °C in Ar. During calcination, the Kirkendall effect resulting from the diffusion/reaction of SPS‐derived carbon and FeOOH leads to the formation of hollow structure carbon with Fe3O4 nanoparticles embedded in it. In the rationally constructed architecture of C/Fe3O4@G, the strongly coupled C/Fe3O4 hollow microspheres are further anchored onto 2D graphene networks, achieving a strong synergetic effect between carbon, Fe3O4, and graphene. As an anode material of Li‐ion batteries (LIBs), C/Fe3O4@G manifests a high reversible capacity, excellent rate behavior, and outstanding long‐term cycling performance (1208 mAh g?1 after 200 cycles at 100 mA g?1). 相似文献
12.
A new electrochemical sensor based on Fe3O4@SiO2‐PANI‐Au nanocomposite was fabricated for modification of glassy carbon electrode (Fe3O4@SiO2‐PANI‐Au GCE). The Fe3O4@SiO2‐PANI‐Au nanocomposite was characterized by TEM, FESEM‐EDS‐Mapping, XRD, and TGA methods. The Fe3O4@SiO2‐PANI‐Au GC electrode exhibited an acceptable sensitivity, fast electrochemical response, and good selectivity for determination of quercetin. Under optimal conditions, the linear range for quercetin concentrations using this sensor was 1.0×10?8 to 1.5×10?5 mol L?1, and the limit of detection was 3.8×10?9 mol L?1. The results illustrated that the offered sensor could be a possible alternative for the measurement of quercetin in food samples and biological fluids. 相似文献
13.
A Facile Molten‐Salt Route for Large‐Scale Synthesis of NiFe2O4 Nanoplates with Enhanced Lithium Storage Capability 下载免费PDF全文
Dr. Gang Huang Dr. Xinchuan Du Dr. Feifei Zhang Dongming Yin Prof. Limin Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(40):14140-14145
Binary metal oxides have been deemed as a promising class of electrode materials for high‐performance lithium ion batteries owing to their higher conductivity and electrochemical activity than corresponding monometal oxides. Here, NiFe2O4 nanoplates consisting of nanosized building blocks have been successfully fabricated by a facile, large‐scale NaCl and KCl molten‐salt route, and the changes in the morphology of NiFe2O4 as a function of the molten‐salt amount have been systemically investigated. The results indicate that the molten‐salt amount mainly influences the diameter and thickness of the NiFe2O4 nanoplates as well as the morphology of the nanosized building blocks. Cyclic voltammetry (CV) and galvanostatic charge–discharge measurements have been conducted to evaluate the lithium storage properties of the NiFe2O4 nanoplates prepared with a Ni(NO3)2/Fe(NO3)3/KCl/NaCl molar ratio of 1:2:20:60. A high reversible capacity of 888 mAh g?1 is delivered over 100 cycles at a current density of 100 mA g?1. Even at a current density of 5000 mA g?1, the discharge capacity could still reach 173 mAh g?1. Such excellent electrochemical performances of the NiFe2O4 nanoplates are contributed to the short Li+ diffusion distance of the nanosized building blocks and the synergetic effect of the Ni2+ and Fe3+ ions. 相似文献
14.
Application of the Fe3O4@1,10‐phenanthroline‐5,6‐diol@Mn nano‐catalyst for the green synthesis of tetrazoles and its biological performance 下载免费PDF全文
Davood Habibi Somayyeh Heydari Antonio Gil Mina Afsharfarnia Alireza Faraji Roya Karamian Mostafa Asadbegy 《应用有机金属化学》2018,32(2)
The Fe3O4 magnetic particles were modified with 1,10‐phenanthroline‐5,6‐diol (Phen) and the related Mn complex (Fe3O4@Phen@Mn) synthesized as a heterogeneous catalyst to be used for the one‐pot three‐component synthesis of various tetrazoles. The catalysts were characterized by several methods, such as the elemental analysis, FT‐IR, X‐ray powder diffraction, dispersive X‐ray spectroscopy, scanning electron microscopy, transmission electron microscopy, dynamic light scattering, thermogravimetric‐differential thermal analysis, vibrating sample magnetometer and X‐ray photoelectron spectroscopy. In addition, the antioxidant and antibacterial activities of the catalyst and its Phen ligand were in vitro screened with 2,2‐diphenyl‐1‐picrylhydrazyl by free radical scavenging methods. Results showed that the synthesized compounds possess strong antioxidant activity (IC50; 0.172 ± 0.005 mg ml?1) as well as a good antibacterial potential in comparison to standards. 相似文献
15.
Prof. Bo Wang Sisi Hu Lin Gu Dr. Di Zhang Dr. Yazhao Li Prof. Huilan Sun Prof. Wen Li Dr. Qiujun Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(71):17097-17102
Reasonably designing and synthesizing advanced electrode materials is significant to enhance the electrochemical performance of lithium ion batteries (LIBs). Herein, a metal–organic framework (MOF, Mil-125) was used as a precursor and template to successfully synthesize the porous mooncake-shaped Li4Ti5O12 (LTO) anode material assembled from nanoparticles. Even more critical, SmF3 was used to modify the prepared porous mooncake-shaped LTO material. The SmF3-modified LTO maintained a porous mooncake-shaped structure with a large specific surface area, and the SmF3 nanoparticles were observed to be attach on the surface of the LTO material. It has been proven that the SmF3 modification can further facilitate the transition from Ti4+ to Ti3+, reduce the polarization of electrode, decrease charge transfer impedance (Rct) and solid electrolyte interface impedance (Rsei), and increase the lithium ion diffusion coefficient (DLi), thereby enhancing the electrochemical performance of LTO. Therefore, the porous mooncake-shaped LTO modified using 2 wt % SmF3 displays a large specific discharge capacity of 143.8 mAh g−1 with an increment of 79.16 % compared to pure LTO at a high rate of 10 C (1 C=170 mAh g−1), and shows a high retention rate of 96.4 % after 500 cycles at 5 C-rate. 相似文献
16.
Ping He Ke Yang Wei Wang Faqin Dong Licheng Du Hongtao Liu 《Russian Journal of Electrochemistry》2013,49(4):354-358
Nanosized Fe3O4-modified activated carbon composites for supercapacitor electrodes have been investigated. Structural and morphological characterizations of activated materials are carried out using X-ray diffraction and scanning electron microscopy, respectively. The electrochemical performances of the composite electrodes are evaluated by cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy. The experimental results show that the specific capacitances of the 10 wt % Fe3O4-modified activated carbon composite electrode (154.3 F g?1) is highly improved compared with that of Fe3O4 (78.5 F g?1) and AC (79.2 F g?1) at the current density of 5 mA cm?2, respectively. The charge/discharge tests show that it could retain 79.6% of its initial capacitance over 1000 cycles, suggesting its potential application for the fabrication of high-quality supercapacitors. 相似文献
17.
Three‐Dimensional Fe2N@C Microspheres Grown on Reduced Graphite Oxide for Lithium‐Ion Batteries and the Li Storage Mechanism 下载免费PDF全文
Dr. Peng Yu Dr. Lei Wang Dr. Fanfei Sun Dr. Dongdong Zhao Dr. Chungui Tian Dr. Lu Zhao Xu Liu Prof. Jianqiang Wang Prof. Honggang Fu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(8):3249-3256
Nanostructured iron compounds as lithium‐ion‐battery anode material have attracted considerable attention with respect to improved electrochemical energy storage and excellent specific capacity, so lots of iron‐based composites have been developed. Herein, a novel composite composed of three‐dimensional Fe2N@C microspheres grown on reduced graphite oxide (denoted as Fe2N@C‐RGO) has been synthesized through a simple and effective technique assisted by a hydrothermal and subsequent heating treatment process. As the anode material for lithium‐ion batteries, the synthetic Fe2N@C‐RGO displayed excellent Li+‐ion storage performance with a considerable initial capacity of 847 mAh g?1, a superior cycle stability (a specific discharge capacity of 760 mAh g?1 remained after the 100th cycle), and an improved rate‐capability performance compared with those of the pure Fe2N and Fe2N‐RGO nanostructures. The good performance should be attributed to the existence of RGO layers that can facilitate to enhance the conductivity and shorten the lithium‐ion diffusion path; in addition, the carbon layer on the surface of Fe2N can avert the structure decay caused by the volume change during the lithiation/delithiation process. Moreover, in situ X‐ray absorption fine‐structure analysis demonstrated that the excellent performance can be attributed to the lack of any obvious change in the coordination geometry of Fe2N@C‐RGO during the charge/discharge processes. 相似文献
18.
This study reports the structural and spectroscopic characterization of a novel metal organic compound formulated as [Fe (bpy)3] [Fe (dipic)2]2.7H2O ( 1 ) (dipic = pyridine‐2,6‐dicarboxylate and bpy = 2,2′‐bipyridine). 1 was investigated by elemental analysis, FT‐IR spectroscopy, powder X‐ray diffraction and single crystal X‐ray diffraction (SC‐XRD), which revealed a triclinic structure of expected composition. Thermal degradation of 1 was also investigated. Complex 1 was used as a precursor to prepare superparamagnetic nanoparticles of Fe3O4 by thermal analysis. The obtained Fe3O4 was characterized by Fourier transformed infrared spectroscopy (FT‐IR), powder X‐ray diffraction (XRD) and scanning electron microscopy (SEM). Fe3O4 nanoparticles were used as a nano‐adsorbent to remove Cd2+ from water at room temperature. The results showed that this nano‐adsorbent is effective in removing Cd2+ from contaminated water sources, and that the maximal effectivity of adsorption occurs at pH = 6. Magnetic measurements of complex 1 and Fe3O4 nanoparticles at room temperature revealed paramagnetic and superparamagnetic behavior, respectively. 相似文献
19.
《Electroanalysis》2017,29(11):2507-2515
In the present study, a novel enzymatic glucose biosensor using glucose oxidase (GOx) immobilized into (3‐aminopropyl) triethoxysilane (APTES) functionalized reduced graphene oxide (rGO‐APTES) and hydrogen peroxide sensor based on rGO‐APTES modified glassy carbon (GC) electrode were fabricated. Nafion (Nf) was used as a protective membrane. For the characterization of the composites, Fourier transform infrared spectroscopy (FTIR), X‐ray powder diffractometer (XRD), and transmission electron microscopy (TEM) were used. The electrochemical properties of the modified electrodes were investigated using electrochemical impedance spectroscopy, cyclic voltammetry, and amperometry. The resulting Nf/rGO‐APTES/GOx/GC and Nf/rGO‐APTES/GC composites showed good electrocatalytical activity toward glucose and H2O2, respectively. The Nf/rGO‐APTES/GC electrode exhibited a linear range of H2O2 concentration from 0.05 to 15.25 mM with a detection limit (LOD) of 0.017 mM and sensitivity of 124.87 μA mM−1 cm−2. The Nf/rGO‐APTES/GOx/GC electrode showed a linear range of glucose from 0.02 to 4.340 mM with a LOD of 9 μM and sensitivity of 75.26 μA mM−1 cm−2. Also, the sensor and biosensor had notable selectivity, repeatability, reproducibility, and storage stability. 相似文献
20.
A Microwave Synthesis of Mesoporous NiCo2O4 Nanosheets as Electrode Materials for Lithium‐Ion Batteries and Supercapacitors 下载免费PDF全文
Anjon Kumar Mondal Dr. Dawei Su Shuangqiang Chen Katja Kretschmer Xiuqiang Xie Prof. Hyo‐Jun Ahn Prof. Guoxiu Wang 《Chemphyschem》2015,16(1):169-175
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. 相似文献