皺褶形貌水合氧化鋁奈米片之合成與模板法製備石墨烯

Synthesis of Crumpled Boehmite Nanosheets and Templated-Synthesis of Graphene

溫哲睿(Je-Ruei Wen)

指導教授 ： 牟中原

國立臺灣大學/理學院/化學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.03006

摘要

利用不需模板之兩階段水熱方式，我們成功合成一具有窗簾般皺摺形貌之水合氧化鋁(boehmite, γ-AlOOH)奈米片。透過研究第一階段水熱(80-95 ℃)與第二階段水熱(150 ℃)時的中間產物，我們知道了該皺摺奈米結構之成形過程，並對此提出一合理的生長機制。此外，藉由操控起始物濃度及水熱反應條件，可調控其獨特之形貌和結晶度。所合成之水合氧化鋁皺褶奈米片具有高達330 m2/g之比表面積，還能經由簡單的鍛燒方式轉相為氧化鋁(γ-Al2O3)，且轉相後仍保有原獨特形貌與比表面積。
石墨烯(graphene)因具備優異的電子、熱、以及力學性質，近年來受到各方學界和業界高度關注。然而，僅有少部分研究著重於如何大量合成可精細調控奈米尺度形貌之石墨烯。於本研究中，我們展示了以化學氣相沉積法，並以氧化鋁皺褶奈米片作為模板，可成功合成具有相同窗簾般皺摺形貌之石墨烯。研究中利用熱重分析和拉曼光譜以鑑定其碳化程度及結晶度。此外，各種不同的石墨烯空心球以及奈米碳管亦可由此模板式製備法所合成。由於其2-3層組成和其獨特的立體結構，具皺褶形貌與空心球外形之石墨烯材料可具有非常高的表面積。

關鍵字

水合氧化鋁 ； 水熱法皺褶 ； 石墨烯 ； 模版法 ； 化學氣相沉積

並列摘要

Boehmite (γ-AlOOH) nanosheets with curtain-like crumpled morphology have been synthesized via template-free hydrothermal process in two-stages. The formation of the crumpled 2D nanostructure was studied at 80-95 ℃ of stage-1 and 150 ℃ of stage-2 hydrothermal processes, and a growth mechanism is proposed. We are able to control the unique morphology and crystallinity by precursor concentrations and the hydrothermal conditions. The crumpled boehmite nanosheets exhibit high BET surface area of ~330 m2/g, and can be simply transformed into γ-Al2O3 with preservation of the morphology and ~90% of surface area after calcination.
Graphene has excellent electronic, mechanical, and thermal properties that draws intense attention in recent years. However, seldom interests have been put on finely controlling the morphology in nanoscale during bulk production. Here we demonstrate templated-synthesis of curtain-like crumpled graphene by crumpled γ-Al2O3 nanosheets via chemical vapor deposition (CVD). Thermogravimetric analysis (TGA) and Raman spectroscopy were employed to investigate the graphitization and crystallinity of graphene. Furthermore, Graphene materials with flake- and tube-based hollow spheres and carbon nanotubes were also successfully synthesized by different alumina templates. The crumpled graphene and graphene flake-based hollow spheres exhibit ultrahigh surface areas, which are attributed to the bilayer and trilayer composition and the unique tree-dimensional morphologies.

並列關鍵字

Boehmite ； Hydrothermal method ； Crumple ； Graphene ； Template method ； Chemical vapor deposition

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