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1.
A novel polyaniline/mesoporous carbon nano-composite electrode for asymmetric supercapacitor 总被引:1,自引:0,他引:1
<正>A novel nano-composite of polyaniline/mesoporous carbon(PANI/CMK-3) was prepared with mesoporous carbon(CMK-3) serving as the support.Electrochemical asymmetric capacitors have been successfully designed by using PANI/CMK-3 composite and CMK-3 as positive and negative electrode,respectively.The results showed that the discharge capacity of the asymmetric capacitor could reach 87.4 F/g under the current density of 5 mA/cm~2 and cell voltage of 1.4 V.The energy density of the asymmetric capacitor was up to 23.8 Wh/kg with a power density of 206 W/kg.Furthermore,PANI/CMK-3-CMK-3 asymmetric capacitor using this PANI/CMK-3 nano-composite could be activated quickly and possess high charge-discharge efficiency. 相似文献
2.
Yaomin Zhao Ling Liu Juan Xu Jie Yang Manming Yan Zhiyu Jiang 《Journal of Solid State Electrochemistry》2007,11(2):283-290
The amorphous hydrous ruthenium oxide/mesoporous carbon composites (denoted as RuO2·xH2O/MC), obtained by loading small amount of amorphous hydrous ruthenium oxide nanoparticles ranged from 0.9 to 5.4% by weight of Ru (denoted as RuO2·xH2O) on mesoporous carbon (MC), were investigated for the first time and were used for supercapacitors. Electrochemical measurements showed that RuO2·xH2O/MC composites not only have an enhanced specific capacitance but also retain the superior rate capability of MC. The RuO2·xH2O/MC composite with Ru loading of 3.6 wt% exhibited an increase of the specific capacitance of approximately 57% (from 115 to 181 F/g) at the scan rate of 25 mV s−1 in 0.1 M H2SO4 aqueous electrolyte. The specific capacitance based on the mass of RuO2 was estimated to be 1,527 F/g, by subtracting the contribution from MC in the composite. Cycle performance tests for RuO2·xH2O/MC composite (3.6 wt% Ru) showed that approximately 2.8% loss of the total capacitance was observed after 1,000 cycles. 相似文献
3.
Yaping Zhou Yongcheng Ma Guojun Lan Haodong Tang Wenfeng Han Huazhang Liu Ying Li 《催化学报》2019,40(1):114-123
Molecular nitrogen is relatively inert and the activation of its triple bond is full of challenges and of significance. Hence, searching for an efficiently heterogeneous catalyst with high stability and dispersion is one of the important targets of chemical technology. Here, we report a Ba-K/Ru-MC catalyst with Ru particle size of 1.5–2.5 nm semi-embedded in a mesoporous C matrix and with dual promoters of Ba and K that exhibits a higher activity than the supported Ba-Ru-K/MC catalyst, although both have similar metal particle sizes for ammonia synthesis. Further, the Ba-K/Ru-MC catalyst is more active than commercial fused Fe catalysts and supported Ru catalysts. Characterization techniques such as high-resolution transmission electron microscopy, N2 physisorption, CO chemisorption, and temperature-programmed reduction suggest that the Ru nanoparticles have strong interactions with the C matrix in Ba-K/Ru-MC, which may facilitate electron transport better than supported nanoparticles. 相似文献
4.
《中国化学快报》2020,31(6):1644-1647
Peony pollen is a cheap and readily available biomass material with a relatively high protein content.In this work,it was employed as an N-rich precursor to prepare the nitrogen-doped porous carbon for supercapacitor application.The porous carbon microspheres were prepared through a hydrothermal method and subsequent carbonization process.Notably,ammonium borofruoride and potassium hydroxide were employed respectively as an etchant and an activator to modify the porosity of the materials.The as prepared ANPPCs-700 has a super high BET specific surface area of 824.69 m~2/g.The microstructure,chemical state and electrochemical properties of the product were investigated in detail.The prepared nitrogen-doped carbon microspheres exhibits excellent specific capacity of 209 F/g at a current density of lA/g and remained 92.5% of the initial capacitance after 5000 deep cycles at 5 A/g. 相似文献
5.
Activated carbon prepared from polyaniline base by K2CO3 activation for application in supercapacitor electrodes 总被引:1,自引:0,他引:1
Xiaoxia Xiang Enhui Liu Limin Li Yanjing Yang Haijie Shen Zhengzheng Huang Yingying Tian 《Journal of Solid State Electrochemistry》2011,15(3):579-585
An activated carbon was prepared from a polyaniline base using K2CO3 as an activating agent. The morphology, surface chemical composition, and surface area of the as-prepared carbon materials were investigated by scanning electron microscope, X-ray photoelectron spectroscopy, and Brunauer?CEmmett?CTeller measurement, respectively. Electrochemical properties of the as-prepared sample were studied by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy measurements in 6?mol?L?1 KOH aqueous solution. Compared with the non-activated carbon, activated carbon showed superior capacitive performance. The activation carbon presented a high specific gravimetric capacitance of 210?F?g?1. The good electrochemical performance of the activated carbon was ascribed to well-developed micropores, high surface area, the presence of nitrogen and oxygen functional groups, and larger pore volume. 相似文献
6.
《Journal of Saudi Chemical Society》2023,27(4):101686
In this work, we proposed a facile one-pot pyrolysis method to conveniently manufacture lignin-derived carbon materials with graded porous construction for use in supercapacitors. The renewable lignin was selected as precursor, while the potassium citrate was used as a pore-forming agent. The properties of the prepared lignin-derived carbon (LAC) and the performance for supercapacitor application were thoroughly evaluated. The LAC at optimal preparation conditions shows a layered porous structure with a large specific surface area of 3174 cm2 g−1 and pore volume of 2.796 cm3 g−1, where the specific capacitance reach to 241 F g−1 at 1 A g−1 scan rate in 6 M KOH electrolyte solution. At the same time, the specific capacitance remains at 220 F g−1 even at an excessive scan velocity of 20 A g−1, while the capacitance retention is still close to 91.3%. The capacitance retention rate is stable above 95% after 10,000 charge/discharge cycles, which shows the desired long-time stability. All these results demonstrate the outstanding properties of the new prepared LAC material and the considerable application potential in the field of electrical energy storage. 相似文献
7.
8.
Silvester Tursiloadi Yu Yamanaka Hiroshi Hirashima 《Journal of Sol-Gel Science and Technology》2006,38(1):5-12
Porous anatase is attractive because of its notable photo-electronic properties. Titania wet gel prepared by hydrolysis of
Ti-alkoxide was immersed in the flow of supercritical CO2 at 60°C and the solvent was extracted (aerogel). Mesoporous TiO2 consisting of anatase nano-particles, about 5 nm in diameter, have been obtained. Thermal evolution of the microstructure
of the aerogel was evaluated by TGA-DTA, N2 adsorption, TEM and XRD, and discussed in comparison with that of the corresponding xerogel. The diffraction peaks of anatase
were found for the as-extracted gel while the xerogel dried at 90°C was amorphous. After calcination at 600°C, the average
pore size of the aerogel, about 20 nm in diameter, was 4 times larger than that of the xerogel, and the pore volume, about
0.35 cm3 g−1, and the specific surface area, about 60 m2 g−1, were 2 times larger than those of the xerogel. XRD peaks of rutile have been found after calcination at 600°C. The particle
sizes of anatase and rutile are about 13 and 25 nm in diameter, respectively. The surface morphology of TiO2 nano-particles has been discussed in terms of their surface fractal dimensions estimated from the N2 gas adsorption isotherms. 相似文献
9.
10.
Ai Bing Chen Wei Ping Zhang Yong Liu Xiu Wen Han Xin He Bao 《中国化学快报》2007,18(8):1017-1020
An in situ reduction method has been developed to fabricate metallic Ag nanoparticles inside the channels of mesoporous carbon CMK-3.This approach combines function of the CMK-3 surface by oxidation using HNO_3 with the subsequent absorption of Ag~ . The resultant nanocomposite materials were characterized by nitrogen adsorption,X-ray diffraction,Auger electron spectroscopy and transmission electron microscopy.Compared with the conventional impregnation method,our approach shows that Ag nanoparticles of 2-4 nm can be uniformly incorporated into CMK-3. 相似文献
11.
Facile synthesis of ordered magnetic mesoporous gamma-Fe2O3/SiO2 nanocomposites with diverse mesostructures 总被引:1,自引:0,他引:1
Wang Y Ren J Liu X Wang Y Guo Y Guo Y Lu G 《Journal of colloid and interface science》2008,326(1):158-165
On the basis of a sol–gel process, a facile, low cost, and one-step approach for preparing ordered magnetic mesoporous γ-Fe2O3/SiO2 nanocomposites by an evaporation-induced self-assembly (EISA) approach is presented. Various mesostructured silica materials (P6mm or Im3m) incorporated with different amounts of iron oxide (nSi/nFe=9/1, 8/2, 7/3, respectively) were synthesized and characterized by XRD, TEM, N2-sorption analyses, and superconducting quantum interference device (SQUID) magnetometer. The HCl-leaching experiments together with TEM micrographs and nitrogen sorption analysis suggested that most of the γ-Fe2O3 domains of several nanometers were embedded in the silica walls, rather than dispersed in the mesopores, which could cause the significant pore clogging reported in some studies. The release behaviors of lysozyme from these magnetic porous nanocomposites were investigated for the possible application of drug targeting and control release. The influence of iron precursors was also studied and a possible mechanism was proposed. The hydrolysis of Fe3+ ions under weakly acidic conditions and the induced formation of SiOFe bonds may account for the synthesis of this kind of nanocomposite. These multifunctional nanostructured materials would have a wide range of applications in toxin removal, catalysis, waste remediation, and biological separation as well as novel drug-carrier technologies. 相似文献
12.
This work described the effect of 3-aminopropyltrimethoxysilane (APTMS) functionalization on the mesoporous ceria nanoparticles (MCNs) toward CO2 capture. The MCN and APTMS-loaded MCN (APTMS-MCN) were prepared by the sol-gel and impregnation method, respectively. The functionalization of APTMS on the MCN enhanced the CO2 binding sites which were observed through the formation of carbamate species from the interaction of CO2 with the NH group. This resulted to the increase of CO2 adsorption capacity of APTMS-MCN with 10-fold higher than that of pristine MCNs. For MCNs, CO2 may be adsorbed onto oxygen basic, oxygen vacant, and hydroxyl sites which further formed polydentate, monodentate, bidentate, and hydrogen carbonate species. In addition to these carbonate species, the adsorption of CO2 on APTMS-MCN has largely occurred through the formation of carbamate species which further enhanced its CO2 uptake. 相似文献
13.
《Comptes Rendus Chimie》2015,18(1):63-74
Activated carbon was prepared from olive stones by physical activation using water vapor at 750 °C. Textural, morphology and surface chemistry characterizations were achieved (nitrogen adsorption, SEM, FTIR and TPD–MS). NO2 adsorption was performed for different inlet gas compositions and temperatures. NO2 may adsorb directly on the oxygenated surface groups, and can also be reduced to NO. Therefore, a second NO2 molecule adsorbs on the oxygen left on the carbon surface. TPD performed after NO2 adsorption showed the presence of various surface groups. The adsorption capacity was about 131 mg/g, which is higher than with several activated carbon prepared from classical lignocellulosic biomass. NO2 reduction into NO decreased with increasing the inlet oxygen concentration. In contrast, a slight decrease in the NO2 adsorption capacity was observed with increasing temperature. It seems that the activated carbons prepared from olive stones by steam activation could be used as efficient adsorbents for NO2 removal. 相似文献
14.
M. Gómez-Cazalilla A. Gurbani A. Jiménez-López 《Journal of solid state chemistry》2007,180(3):1130-1140
A series of Al-containing SBA-15 type materials with different Si/Al ratio, were prepared by post-synthesis modification of a pure highly ordered mesoporous silica SBA-15 obtained by using sodium silicate as silica source, and amphiphilic block copolymer as structure-directing agent. A high level of aluminum incorporation was achieved, reaching an Si/Al ratio of up to 5.5, without any significant loss in the textural properties of SBA-15. These materials were fully characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), 27Al NMR spectroscopy, and N2 adsorption at 77 K. The acid properties of these materials have been evaluated by NH3-TPD, adsorption of pyridine and deuterated acetonitrile coupled to FTIR spectroscopy. The effective acidity of these materials was evaluated using two catalytic reactions: 2-propanol dehydrogenation and 1-butene isomerization. The adsorption of basic probe molecules and the catalytic behavior revealed an evolution of the acid properties with the Al content. These studies have shown that the Al-SBA-15 materials contain Brønsted and Lewis acid sites with medium acidity which makes them appropriate to be used as acid catalysts in heterogeneous catalysis, catalytic supports, and adsorbents. 相似文献
15.
Extraction of cationic surfactant templates from MCM-41, MCM-48, SBA-1 and SBA-3 has been conducted using CH3OH-modified CO2 supercritical fluid. The supercritical fluid extraction (SFE) has been integrated with thermogravimetry (TG), X-ray diffraction (XRD) and N2 adsorption-desorption to evaluate extraction efficiency and structural stability of mesoporous materials. Experiments of optimization indicate that the conditions of 90 bar, 85 °C, CH3OH/CO2 = 0.1/1.0 ml/min and 3 h are most suitable for the SFE of cationic templates. 76-95% of the cationic templates can be extracted from the mesoporous materials. XRD and N2 adsorption-desorption studies illustrate that SFE possesses some advantages over calcination in maintaining mesoporous uniformity and structural stability when used to remove templates. The impact of curing on mesoporous structure is also dealt with. 相似文献
16.
Haixia Fan Yong ZhangDan Wu Hongmin MaXiaojing Li Yan LiHuan Wang He LiBin Du Qin Wei 《Analytica chimica acta》2013
In this contribution, mesoporous carbon nanospheres (MCN) were used to fabricate a label-free electrochemical immunosensor for breast cancer susceptibility gene (BRCAl). The detection platform was constructed by conjugation of anti-BRCA1 on glassy carbon electrodes which were modified by mesoporous carbon nanospheres–toluidine blue nanocomposite (MCN–TB)/room temperature ionic-liquid (RTIL) composited film. TB was adsorbed onto MCN and acted as a redox probe. The electroactivity of TB was greatly enhanced in the presence of MCN. The good conductivity of MCN and BMIM·BF4 could promote the electron transfer and thus enhance the detection sensitivity. Moreover, the large surface area of MCN and the protein-binding properties of BMIM·BF4 could greatly increase the antibody loading. The specific antibody–antigen immunoreaction on the electrode surface resulted in a decrease of amperometric signal of the electrode. Under optimized conditions, the amperometric signal decreased linearly with BRCAl concentration in the range of 0.01–15 ng mL−1 with a low detection limit of 3.97 pg mL−1. The immunosensor exhibits high sensitivity, good selectivity and stability. 相似文献
17.
<正>Mesoporous carbon(MC) with surface area of 380 m~2/g was prepared and employed as the carbon support of Pt catalyst for counter electrode of dye-sensitized solar cells.Pt/MC samples containing 1 wt%Pt were prepared by reducing chloroplatinic acid on MC using wet impregnation.It was found that Pt nanoparticles were uniform in size and highly dispersed on MC supports.The average size of Pt nanoparticles is about 3.4 nm.Pt/MC electrodes were fabricated by coating Pt/MC samples on fluorine-doped tin oxide glass.The overall conversion efficiency of dye-sensitized solar cells with Pt/MC counter electrode is 6.62%,which is higher than that of the cells with conventional Pt counter electrode in the same conditions. 相似文献
18.
Synthesis of functionalized mesoporous carbon by an easy-accessed method is of great importance towards its practical applications.Herein,an evaporation induced self-assembly/carbonization(EISAC) method was developed and applied to the synthesis of sulfonic acid group functionalized mesoporous carbon(SMC).The final mesoporous carbon obtained by EISAC method possesses wormlike mesoporous structure,uniform pore size(3.6 nm),large surface area of 735 m2/g,graphitic pore walls and rich sulfonic acid group.Moreover,the resultant mesoporous carbon achieves a superior electrochemical capacitive performances(216 F/g)to phenolic resin derived mesoporous carbon(OMC,152 F/g)and commercial activated carbon(AC,119 F/g). 相似文献
19.
Xiangjie Bo 《Analytica chimica acta》2010,675(1):29-668
Onion-like mesoporous carbon vesicle (MCV) with multilayer lamellar structure was synthesized by a simply aqueous emulsion co-assembly approach. Palladium (Pd) nanoparticles were deposited on the MCV matrix (Pd/MCV) by chemical reduction of H2PdCl4 with NaBH4 in aqueous media. Pd(X)/MCV (X wt.% indicates the Pd loading amount) nanocomposites with different Pd loading amount were obtained by adjusting the ratio of precursors. The particular structure of the MCV results in efficient mass transport and the onion-like layers of MCV allows for the obtainment of highly dispersed Pd nanoparticles. The introduction of Pd nanoparticles on the MCV matrix facilitates hydrazine oxidation at more negative potential and delivers higher oxidation current in comparison with MCV. A linear range from 2.0 × 10−8 to 7.1 × 10−5 M and a low detection limit of 14.9 nM for hydrazine are obtained at Pd(25)/MCV nanocomposite modified glassy carbon (GC) electrode. A nonenzymatic amperometric sensor for hydrogen peroxide based on the Pd(25)/MCV nanocomposite modified GC electrode is also developed. Compared with MCV modified GC electrode, the Pd(25)/MCV nanocomposite modified GC electrode displays enhanced amperometric responses towards hydrogen peroxide and gives a linear range from 1.0 × 10−7 to 6.1 × 10−3 M. The Pd(25)/MCV nanocomposite modified GC electrode achieves 95% of the steady-current for hydrogen peroxide within 1 s. The combination of the unique properties of Pd nanoparticles and the porous mesostructure of MCV matrix guarantees the improved analytical performance for hydrazine and hydrogen peroxide. 相似文献
20.
The performance of carbon electrodes depends on the surface pretreatment methods. An exclusively cathodically pretreated
glassy carbon electrode (GCE) shows very good activity towards monomeric molybdate(VI) ion adsorption and its reduction. X-ray
photoelectron spectroscopy studies reveal the creation of >C–O– surface groups on cathodisation. A strong interaction between
the Mo(VI) ion and these >C–O– surface groups with the formation of Mo(V) is responsible for the activation of the cathodically
pretreated GCE surface.
Received: 5 January 1998 / Accepted: 10 January 1999 相似文献