Combinatorial Optimization of Heterogeneous Catalysts Used in the Growth of Carbon Nanotubes

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• 作者：Alan M. Cassell ; Sunita Verma ; Lance Delzeit ; M. Meyyappan ; and Jie Han
• 刊名：Langmuir
• 出版年：2001
• 出版时间：January 23, 2001
• 年：2001
• 卷：17
• 期：2
• 页码：260 - 264
• 全文大小：519K
• 年卷期：v.17,no.2(January 23, 2001)
• ISSN：1520-5827

文摘

Libraries of liquid-phase catalyst precursor solutions were printed onto iridium-coated silicon substratesand evaluated for their effectiveness in catalyzing the growth of multiwalled carbon nanotubes (MWNTs)by chemical vapor deposition (CVD). The catalyst precursor solutions were composed of inorganic saltsand a removable triblock copolymer (EO)₂₀(PO)₇₀(EO)₂₀ (EO = ethylene oxide, PO = propylene oxide)structure-directing agent (SDA), dissolved in ethanol/methanol mixtures. Sample libraries were quicklyassayed using scanning electron microscopy after CVD growth to identify active catalysts and CVD conditions.Composition libraries and focus libraries were then constructed around the active spots identified in thediscovery libraries to understand how catalyst precursor composition affects the yield, density, and qualityof the nanotubes. Successful implementation of combinatorial optimization methods in the developmentof highly active, carbon nanotube catalysts is demonstrated, as well as the identification of catalystformulations that lead to varying densities and shapes of aligned nanotube towers.