Dissociation of carbon dioxide and creation of carbon particles and films at room temperature
Dissociation of carbon dioxide and creation of carbon particles and films at room temperature
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DOI：
10.1088/1367-2630/9/9/321
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发表时间：
2007-09-10
影响因子：
3.3
通讯作者：
Mikhalovsky, Sergey
中科院分区：
文献类型：
--
作者：
Fukuda, Takahiro;Maekawa, Toru;Mikhalovsky, Sergey
当流体接近其气液临界点时，由于大分子簇的形成，比热和压缩性等物理特性会发生变化。由于存在较大的团簇，入射光无法穿透近临界流体，这种现象称为临界乳光。在本文中，我们用波长为213、266、355和532 nm的激光束照射临界温度和压力为31.0℃和7.38MPa的近临界二氧化碳(ncCO(2))，结果表明，当系统设置得非常接近临界点时，在213和266 nm的情况下会出现临界乳光，CO2会解离并产生颗粒。波长，而当温度偏离临界值时不会产生颗粒。我们还在 ncCO(2) 上施加了直流电场，并用 213 和 266 nm 波长的激光束照射，发现在阳极和阴极上都形成了颗粒。随着电场强度的增加，电极上形成薄膜。电子衍射图和能量色散X射线、俄歇电子、X射线光电子和拉曼光谱分析表明颗粒和薄膜由无定形碳组成。
As fluids approach their gas-liquid critical points, the physical properties such as the specific heat and compressibility diverge due to the formation of large molecular clusters. Incident light cannot penetrate near-critical fluids because of the large clusters, a phenomenon known as critical opalescence. In this paper, we irradiate near-critical carbon dioxide (ncCO(2)), the critical temperature and pressure of which are 31.0 degrees C and 7.38MPa, with a laser beam of 213, 266, 355 and 532 nm wavelength and show that CO2 is dissociated and particles are produced when the system is set so close to the critical point that critical opalescence occurs in the case of 213 and 266 nm wavelength, whereas no particles are produced when the temperature is made to deviate from the critical value. We also apply a dc electric field to ncCO(2) during irradiation with a laser beam of 213 and 266 nm wavelength and find that particles are formed on both anode and cathode. As the intensity of the electric field increases, films are formed on the electrodes. Electron diffraction patterns and energy-dispersive x-ray, Auger electron, x-ray photoelectron and Raman spectroscopic analyses show that the particles and films are composed of amorphous carbon.