石墨烯-二硫化鉬凡得瓦力異質接面於產氫反應之研究

Abstract

化石燃料雖然提供人類日常生活所需的能源，但卻也同時對環境造成許多的汙染。因此，人類急於尋找與發展一乾淨且可再生的替代能源。過去幾年十來，由於氫氣擁有高的能量密度，因此被視為極具潛力的能源攜帶者。此外，氫氣可以被儲存、運送以及廣泛地運用，而使用過程中的副產物也不會對環境造成傷害。儘管如此，現今氫氣主要來源是藉由蒸氣甲烷重組的方式，在過程中仍伴隨著大量的二氧化碳排放。因此，電化學水解被視為是一個最具有潛力的方式來產生氫氣。 為了提高產氫的效率，使用具有高度活性的催化材料是一個重要的關鍵。其中，白金是一個大家所熟知最好的催化物質；然而，由於它的稀少性及高成本，其大規模的發展及應用仍然受限。近年來，二維材料的發現再次引起科學家們對催化產氫的關注；其中，二硫化鉬因其獨特的晶體結構和性質，許多團隊開始探討其作為產氫催化物的表現。因此，如何提升二硫化鉬的催化能力將是我論文的研究主體。 過去幾年來，許多的研究結果提出許多不同的方法皆可以提升二硫化鉬的催化能力。其中，利用微影技術所製作出來的單片二維材料的催化元件將可局部地探討二硫化鉬材料的本質催化能力。不過，因其低導電性的半討體性質以及元件的微電極中存在著接觸電阻的限制，導致二硫化鉬的催化能力受到影響。近年來，由於單層碳原子所組成的石墨烯具有優異的物理特性，使其成為電子元件中改善接觸電阻的角色。因此，在此論第一部分，憑藉著發光二極體微影技術，我將呈現如何製作一個石墨烯為微電極的二硫化鉬催化元件。在第二部分，我將初步探討石墨烯對其電子傳輸的改善效果。在最後一部分，我將建立一個適用於任何單片二維材料的催化平台來探討石墨烯—二硫化鉬異質接面對二硫化鉬本質催化能力的提升。

Fossil fuel supply energy for the daily life of humans, but they simultaneously cause many pollutions in the environment. Thus, people urgently look for and develop a clean and renewable alternative energy. Over the past decades, due to ultrahigh energy density of hydrogen, it is deemed as a promising energy carrier. In addition, hydrogen can be not only stored, transported, and widely utilized, but its by-product is also not harmful for the environment. Nevertheless, the major hydrogen production results from steamed methane reforming, which still emit amount of carbon dioxide. Therefore, water electrolysis is regarded as the most promising method to produce hydrogen. To enhance the efficiency of hydrogen production, using a material with highly catalytic activity is a critical key. Among of most catalytic material, platinum is the best catalytic substance so far. However, owing to its scarcity and high cost, large-scale development and application is still limited. Recently, a significantly process in two-dimensional materials arouse scientists’ attention for the issue of hydrogen production. Among these materials, since molybdenum disulfide (MoS2) has unique crystal structures and properties, many groups start to study its performance served as a catalytic material to produce hydrogen. Hence, how to enhance the catalytic activity of MoS2 is my thesis topic. In the past few years, many experimental results report various methods can boost the catalytic activity of MoS2. In these experiments, using a catalytic device of two-dimensional material of single sheet fabricated by lithographic technique can locally investigate the catalytic activity of MoS2. Admittedly, because of its semi-conductive property, low conductivity, and the restriction of contact resistance existing in microelectrode of the device, the catalytic performance of MoS2 is affected. Currently, due to remarkably physical properties of graphene, an atomic-based material, it plays a role in improving the contact resistance in the electronic devices. Hence, in the first part of this thesis, by utilizing LED lithographic technique, we demonstrate how to fabricate a catalytic MoS2 device with graphene contact microelectrode. In the second part, we initially investigate the results of graphene contact for electron transport of the device. In the last part, we establish a suitable HER platform for catalytic experiment of any isolated two-dimensional material to study the enhancement of MoS2 catalytic performance by using graphene-MoS2 heterojunction.