石墨烯於電化學及光電化學元件之研究

The Role of Single Graphene Atomic Sheets for Electrochemical and Photoelectrochemical Cells

王哲儀(Jhe-Yi Wang)

指導教授 ： 陳俊維

國立臺灣大學/工學院/材料科學與工程學研究所/碩士(2017年)

https://doi.org/10.6342/NTU201701988

摘要

石墨烯為一獨立的二維材料，其由單層碳原子所組成，因為特殊的能帶結構以及原子排列方式，而展現優異的載子傳導性質，此外單層石墨烯於可見光波段擁有高達 97.7%的穿透率，使其具有潛力作為蕭基接面之太陽能電池的透明電極。近年來，石墨烯與矽形成之蕭基接面作為光電化學元件也受到許多矚目，因此如何提升石墨烯/矽之蕭基接面光電化學元件的表現為我的研究主軸。
為了滿足我們日益增長的能源需求，科學家們想要利用光電化學元件分解水生成化學燃料。然而，如何在光電化學反應過程中設計有效的催化物是一個主要的挑戰。由於低成本和高穩定性，碳基催化物在可再生能源技術中一直備受關注。在此論文的第一部分，我們成功的把單層石墨烯與矽形成的蕭基接面作為光電化學元件並應用於產氫。接著，發現將孤立石墨烯裝飾於單層石墨烯與矽形成的蕭基接面上時，孤立石墨烯可作為催化物，提升元件表現。在第二部分，我們藉由量測單片石墨烯的產氫表現去了解單片石墨烯的催化特性。憑藉發光二極體(LED) 投影之微影技術，我們能夠單單只量測石墨烯的基面(basal plane)或邊界(edge)，在比較實驗結果後也發現石墨烯邊界的催化效果較顯著。

關鍵字

石墨烯 ； 光電化學元件 ； 蕭基接面 ； 石墨烯邊界 ； 產氫

並列摘要

Graphene, a two-dimensional sheet of sp2-hybridized carbon atoms, exhibits excellent carrier transport because of its unique two-dimensional energy dispersion. Moreover, a single-layer graphene shows high transparency with 97.7% transmittance, making it a candidate for transparent electrode in Schottky junction solar cell. Besides, graphene/silicon Schottky junction for photoelectrochemical cells has also draw much attention recently. Hence, how to enhance the performance of graphene/silicon Schottky junction photoelectrochemical cells is my thesis topic.
Photoelectrochemical cells are used to split water to generate chemical fuels to satisfy our ever-increasing energy demands. However, it is a major challenge to design efficient catalysts to use in the photoelectochemical process. Recently, carbon-based catalysts have been attracting attention in renewable energy technologies due to low cost and high stability. In the first part of this thesis, we successfully demonstrated monolayer graphene/silicon Schottky junction photoelectrochemical cells for hydrogen evolution reaction(HER). And then, we found that isolated graphene can be used as a catalyst after decorating it onto monolayer graphene/silicon Schottky junction photoelectrochemical cells. In the second part, we have carried out a study to understand the role of single graphene sheets on the catalytic properties by measuring the HER performance of individual monolayers of chemical vapour deposition (CVD) graphene atomic sheets. By using LED projection lithography patterning, we have been able to measure the catalytic properties of only the basal plane(edge-covered) or only the edges(edge-exposed). The edge site of graphene is more electrochemically active, after comparison between edge-covered and edge-exposed graphene sheet.

並列關鍵字

graphene ； photoelectrochemical cell ； Schottky junction ； graphene edge ； HER

參考文獻

43. 陳俊吉. 石墨烯與矽之蕭基接面光電化學元件於產氫之研究. 臺灣大學, 2016.

1. Boehm, H.-p., Nomenclature and terminology of graphite intercalation compounds (IUPAC Recommendations 1994). Pure & Appl. Chem. 1994, 66.

2. Geim, A. K., Graphene_Status and Prospects. Science 2009, 324, 1530-1534.

3. Young, R. J.; Kinloch, I. A.; Gong, L.; Novoselov, K. S., The mechanics of graphene nanocomposites: A review. Composites Science and Technology 2012, 72 (12), 1459-1476.

4. K. S. Novoselov, A. K. G., Electric field effect in atomically thin carbon films. science 2004, 306.