Processing, growth mechanism and thermodynamic calculations of carbon foam with a hollow tetrapodal morphology – Aerographite
Processing, growth mechanism and thermodynamic calculations of carbon foam with a hollow tetrapodal morphology – Aerographite
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DOI：
10.1016/j.apsusc.2018.11.016
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发表时间：
2019-03
影响因子：
6.7
通讯作者：
J. Marx;M.R.D. Lewke;D. Smazna;Y. Mishra;R. Adelung;K. Schulte;B. Fiedler
中科院分区：
文献类型：
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作者：
J. Marx;M.R.D. Lewke;D. Smazna;Y. Mishra;R. Adelung;K. Schulte;B. Fiedler
Aerographite 是一种具有四足形态的 3D 互连碳泡沫。 Aerographite 的合成基于两步过程：首先在火焰传输合成 (FTS) 中生产氧化锌 (ZnO) 模板，然后在化学气相沉积过程 (CVD) 中复制到碳结构中。本研究通过扫描电子显微镜 (SEM)、透射电子显微镜 (TEM) 和拉曼光谱分析断续合成中新形成的碳结构，提出了这种 3D 碳泡沫的生长模型。此外，还计算了基于 ZnO 还原和碳层形成的复制 CVD (rCVD) 过程的吉布斯自由能。在 CVD 过程中，注入的碳沉积在 ZnO 四足体的表面上，同时由于 ZnO 与注入源中的氢气 (H2) 反应，将 ZnO 还原成气态锌和水蒸气，从而复制到碳结构中。将 ZnO 模板复制到碳结构中是基于外延控制过程与催化石墨化相结合，从而通过碳复制模板结构的形态。此外，还解释了生长过程对碳层排列和缺陷形成的影响。
Aerographite is a 3D interconnected carbon foam with a tetrapodal morphology. The synthesis of Aerographite is based on a two-step process: first the production of a zinc oxide (ZnO) template in a flame transport synthesis (FTS) followed by the replication into the carbon structure in a chemical vapour deposition process (CVD). This study presents a growth model of this 3D carbon foam via analyzing the newly formed carbon structure in an interrupted synthesis by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Moreover, the Gibbs free energy of the occurred replica CVD (rCVD) process, based on the reduction of ZnO and the formation of carbon layers, was calculated. During the CVD process the injected carbon deposits on the surfaces of the ZnO tetrapods, while simultaneously the replication into the carbon structure takes place, as a result of the reduction of ZnO into gaseous zinc and water vapour, which is due to the reaction of ZnO with the hydrogen (H2) from the injected source. This replication of the ZnO template into a carbon structure is based on an epitaxial controlled process combined with a catalytic graphitization, whereby the morphology of the template structure is replicated by the carbon. Furthermore, the influence of the growth process on the arrangement of carbon in layers and formation of defects was explained.