Fe/Cu修饰氮掺杂碳纳米管的构筑及催化性能

Construction and Catalytic Properties of Fe/Cu Modified Nitrogen-Doped Carbon with Carbon Nanotube

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I_(3)^(-)/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I_(3)^(-)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。

Cu-modified nitrogen-doped carbon(Cu-N-C)and Fe/Cu-modified nitrogen-doped carbon with carbon nanotube(Fe/Cu-N-C/CNT)catalysts were prepared by in situ chemical synthesis combined with an ion exchange method.As counter electrode in dye-sensitized solar cells(DSSCs),the electrochemical properties and photovoltaic performance of these two catalysts in I_(3)^(-)/I-electrolyte were explored.The structure and morphology of as-prepared catalysts were characterized by X-ray diffraction(XRD),Raman spectra,X-ray photoelectron spectra(XPS),and field emission scanning electron microscope(FESEM).The results showed that the graphitization degree of Fe/Cu-NC/CNT was higher than that of Cu-N-C,which is more favorable for charge transfer during I_(3)^(-)reduction process.The photovoltaic tests results showed that the DSSCs based on Fe/Cu-N-C/CNT CE achieved a power conversion efficiency(PCE)of 7.55%,higher than Cu-N-C(6.99%)and Pt(6.76%)under the same conditions.50 cycles continuous cyclic voltammetry scanning showed that Fe/Cu-N-C/CNT had better electrochemical stability than Cu-N-C.This robust behavior can be mainly attributed to the synergistic effect between the bimetallic active sites(Fe/Cu)and the nitrogen-doped carbon network with CNTs,which results in a pronounced decrease in the charge-transfer resistance and superior device stability.