Photo-ignition process of multiwall carbon nanotubes and ferrocene by continuous wave Xe lamp illumination
Photo-ignition process of multiwall carbon nanotubes and ferrocene by continuous wave Xe lamp illumination
复制标题
连续波氙灯照明下多壁碳纳米管和二茂铁的光点火过程
DOI：
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发表时间：
2017
影响因子：
3.1
通讯作者：
G. Mele
中科院分区：
文献类型：
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作者：
P. Visconti;P. Primiceri;D. Longo;L. Strafella;P. Carlucci;M. Lomascolo;A. Cretí;G. Mele
本工作旨在通过使用连续波（CW）氙（Xe）光源来研究和表征多壁碳纳米管/二茂铁混合物的光点火现象，以便通过采用与先前研究中使用的不同类型的光源（即，脉冲氙灯）。通过使用选择性滤光器改变所用混合物的重量比、发光功率和入射光的波长范围来进行实验性光点火测试。为了更好地解释光致点火过程，获得了MWCNT/二茂铁混合物和仅二茂铁的吸收光谱。实验结果表明，根据先前公布的结果，当使用不同类型的光源（即，脉冲与CW CW CW光源）。此外，当朝向紫外（UV）区域移动时，需要较少的光功率来触发光点火。这与测量的吸收光谱一致，其对于MWCNT/二茂铁混合物和仅在甲苯中稀释的二茂铁在UV-可见光区域中呈现较高的吸收值。最后，点火现象的化学物理解释，提出了二茂铁光激发，由于光子吸收，产生二茂铁本身在其激发形式，因此能够促进电子转移到多壁碳纳米管。通过这种方式，所产生的自由基物质FeCp 2+和MWCNT−很容易与氧气反应，从而引起MWCNT/二茂铁样品的着火。
This work aims to investigate and characterize the photo-ignition phenomenon of MWCNT/ferrocene mixtures by using a continuous wave (CW) xenon (Xe) light source, in order to find the power ignition threshold by employing a different type of light source as was used in previous research (i.e., pulsed Xe lamp). The experimental photo-ignition tests were carried out by varying the weight ratio of the used mixtures, luminous power, and wavelength range of the incident Xe light by using selective optical filters. For a better explanation of the photo-induced ignition process, the absorption spectra of MWCNT/ferrocene mixtures and ferrocene only were obtained. The experimental results show that the luminous power (related to the entire spectrum of the Xe lamp) needed to trigger the ignition of MWCNT/ferrocene mixtures decreases with increasing metal nanoparticles content according to previously published results when using a different type of light source (i.e., pulsed vs CW Xe light source). Furthermore, less light power is required to trigger photo-ignition when moving towards the ultraviolet (UV) region. This is in agreement with the measured absorption spectra, which present higher absorption values in the UV–vis region for both MWCNT/ferrocene mixtures and ferrocene only diluted in toluene. Finally, a chemo-physical interpretation of the ignition phenomenon is proposed whereby ferrocene photo-excitation, due to photon absorption, produces ferrocene itself in its excited form and is thus capable of promoting electron transfer to MWCNTs. In this way, the resulting radical species, FeCp2+∙ and MWCNT−, easily react with oxygen giving rise to the ignition of MWCNT/ferrocene samples.