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991.
通过简单的原位化学合成法结合离子交换法制备了Cu修饰氮掺杂碳(Cu-N-C)和Fe/Cu修饰氮掺杂碳纳米管(Fe/Cu-N-C/CNT),并系统评估了2种催化剂作为染料敏化太阳能电池(dye-sensitized solar cells,DSSCs)对电极在I3-/I-体系中的电化学特性和光伏性能。采用X射线衍射(XRD)、拉曼(Raman)、X射线光电子能谱(XPS)和场发射扫描电镜(FESEM)对合成的催化剂进行组分和形貌表征。结果表明:纳米管状的Fe/Cu-N-C/CNT的石墨化程度比纳米颗粒状的Cu-N-C更高,更有利于I3-还原反应中电荷的传输。光伏性能测试结果表明:基于Fe/Cu-N-C/CNT对电极的DSSCs的光电能量转换效率(power conversion efficiency,PCE)达到7.55%,高于相同测试条件下Cu-N-C(6.99%)和Pt(6.76%)对电极的PCE。50圈连续循环伏安测试结果表明:Fe/Cu-N-C/CNT催化剂具有比Cu-N-C更好的电化学稳定性。 相似文献
992.
In Situ X‐Ray Diffraction Studies on Structural Changes of a P2 Layered Material during Electrochemical Desodiation/Sodiation
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Young Hwa Jung Ane S. Christiansen Rune E. Johnsen Poul Norby Do Kyung Kim 《Advanced functional materials》2015,25(21):3227-3237
Sodium layered oxides with mixed transition metals have received significant attention as positive electrode candidates for sodium‐ion batteries because of their high reversible capacity. The phase transformations of layered compounds during electrochemical reactions are a pivotal feature for understanding the relationship between layered structures and electrochemical properties. A combination of in situ diffraction and ex situ X‐ray absorption spectroscopy reveals the phase transition mechanism for the ternary transition metal system (Fe–Mn–Co) with P2 stacking. In situ synchrotron X‐ray diffraction using a capillary‐based microbattery cell shows a structural change from P2 to O2 in P2–Na0.7Fe0.4Mn0.4Co0.2O2 at the voltage plateau above 4.1 V on desodiation. The P2 structure is restored upon subsequent sodiation. The lattice parameter c in the O2 structure decreases significantly, resulting in a volumetric contraction of the lattice toward a fully charged state. Observations on the redox behavior of each transition metal in P2–Na0.7Fe0.4Mn0.4Co0.2O2 using X‐ray absorption spectroscopy indicate that all transition metals are involved in the reduction/oxidation process. 相似文献
993.
Wearable energy storage devices that can be used in the garment industry are strongly required to power E-textiles. In this article, polypyrrole (PPy) nanorods were deposited on cotton fabrics via in situ polymerization of pyrrole in the presence of the fibrillar complex of FeCl3 and methyl orange as a reactive self-degraded template. The obtained fabrics could be directly used as supercapacitor electrodes, with a maximum specific capacitance of 325 F g−1 and an energy density of 24.7 Wh kg−1 at a current density of 0.6 mA cm−2. The capacitance remained higher than 200 F g−1 after 500 cycles. 相似文献
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995.
Electrokinetic particle translocation through a nanopore containing a floating electrode 总被引:1,自引:0,他引:1
Electrokinetic particle translocation through a nanopore containing a floating electrode is investigated by solving a continuum model, composed of the coupled Poisson-Nernst-Planck (PNP) equations for the ionic mass transport and the modified Stokes equations for the flow field. Two effects due to the presence of the floating electrode, the induced-charge electroosmosis (ICEO) and the particle-floating electrode electrostatic interaction, could significantly affect the electrokinetic mobility of DNA nanoparticles. When the electrical double layers (EDLs) of the DNA nanoparticle and the floating electrode are not overlapped, the particle-floating electrode electrostatic interaction becomes negligible. As a result, the DNA nanoparticle could be trapped near the floating electrode arising from the induced-charge electroosmosis when the applied electric field is relatively high. The presence of the floating electrode attracts more ions inside the nanopore resulting in an increase in the ionic current flowing through the nanopore; however, it has a limited effect on the deviation of the current from its base current when the particle is far from the pore. 相似文献
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998.
MWNTs-IL-Gel/GCE, a glassy carbon electrode modified with multiwalled carbon nanotubes (MWNTs) and ionic liquids (IL), was developed to serve as a sensor for simultaneous determination of Hydroquinone (HQ) and catechol (CC) in this paper. The modified GCE showed two well-defined redox waves for HQ and CC in both CV and DPV with a peak potential separation of ca. 0.1 V, which was large enough for simultaneous detection. The results revealed that the oxidation of HQ and CC with the enhancement of the redox peak current and the decrease of the peak-to-peak separation exhibit excellent electrocatalytic behaviors. A high sensitivity of 1.8×10(-7)M with detection limits of 6.7×10(-8)M and 6.0×10(-8)M (S/N=3) for HQ and CC were obtained. Moreover, the constants of apparent electron transfer rate of HQ and CC at MWNTs-IL-Gel/GCE were calculated as 7.402 s(-1) and 8.179 s(-1), respectively, and the adsorption quantity of HQ and CC was 1.408×10(-6) mol cm(-2) with chronocoulometry. The developed sensor can be applied to determinate directly of HQ and CC in aqueous solution. 相似文献
999.
Wang Y 《Colloids and surfaces. B, Biointerfaces》2011,88(2):614-621
A sensitive and selective electrochemical method was developed for simultaneous determination of uric acid (UA), xanthine (XA) and hypoxanthine (HX) based on a poly (pyrocatechol violet)/carboxyl functionalized multi-walled carbon nanotubes composite film modified electrode. The preparation and basic electrochemical performance of the novel composite film modified glassy carbon electrode were investigated in details. The electrochemical behaviors of UA, XA and HX at the modified electrode were studied by cyclic voltammetry. The results showed that this new electrochemical sensor exhibited excellent electrocatalytic activity towards the oxidation of the three analytes. The mechanism of catalysis was discussed. The anodic peaks of the three species were well defined with lowered oxidation potential and enhanced oxidation peak currents, so the modified electrode was used for simultaneous voltammetric measurement of UA, XA and HX by differential pulse voltammetry. Under the optimum conditions, the detection limits were 0.16 μmol L(-1) for UA, 0.05 μmol L(-1) for XA and 0.20 μmol L(-1) for HX, respectively (S/N of 3). The proposed method has been successfully applied to simultaneous determination of UA, XA and HX in human serum samples. 相似文献
1000.
在氧化铟锡( ITO)导电玻璃表面电泳沉积制备ZnO-C60和ZnO-MWCNT复合涂层电极,经后续热处理增强其结合强度,通过SEM观察2种电极复合涂层的表面形貌,并使用CHI 705电化学分析仪和PMI-E电致化学发光系统测定其光电性质.结果表明,ZnO-C60复合涂层电极具有较高的稳定性,在可见光辐照下,该电极显示... 相似文献