科技部新聞稿
利用超薄之原子層材料，以太陽光產生潔淨氫能
由臺灣大學、臺灣科技大學、東海大學所組成之跨校際之「新世代能源研究團隊」之研究成果，刊登於能源研究頂尖期刊Advanced Energy Materials
日期：109年2月12日
發稿單位：自然科學及永續研究發展司
聯絡人：郭廷洋助理研究員
電話：(02)2737-7465
Email：tykuo@nstc.gov.tw
在科技部「尖端晶體材料開發及製作計畫」長期的支持下，由臺灣大學陳俊維教授，臺灣科技大學黃炳照教授與東海大學王迪彥教授所組成之跨校際之「新世代能源研究團隊」，最近在再生潔淨能源相關之研究，「利用太陽能轉換氫能」 相關議題，有重大之突破：研發出以原子層材料石墨烯與矽基材料結合之新型的光電化學製氫技術。
面對全球暖化，及石化能源造成污染之問題，新的替代能源研究相關議題，是目前全世界最重要之研究課題之一。特別是臺灣在積極尋求能源多元化的議題下，如何發展出好的替代能源，是目前相當重要之研究議題。雖然太陽能被視為最重要的再生能源之一，且目前已逐漸被廣泛應用於日常生活。然而其最大的瓶頸，是太陽能無法被儲存，以至於在沒有太陽光照射時，就無法使用。因此科學家致力研究，如何有效將太陽能轉換為”燃料(fuel)”，利於儲存與運輸，並且在任何時候皆可被使用。將有機會解決太陽能在沒有日照時，就無法使用之瓶頸。
「氫能」，是目前科學界全力發展之潔淨能源之一。以氫能為主之燃料電池，在運作中無污染，僅產生純水，不會排放任何廢氣如二氧化碳。因此被認為是未來最有潛力之潔淨能源。然而，氫氣的製備，一般來說需要用到大量的電力，在成本上一直是需要克服的瓶頸。因此，有效利用太陽能直接將水分解，產生潔淨能源”氫氣”，是目前科學界重要的研究方向。目前，最常用的太陽光分解產氫的材料為大家熟悉的矽材。矽有其低能隙可涵蓋很廣的太陽光譜的吸收與市場上容易取得的優點。然而利用矽來做光分解產氫，其最大問題為其在電解液中的不穩定性與矽基板的高反射率。
陳俊維教授所帶領之研究團隊，利用新穎之原子層材料石墨烯(Graphene)，與矽形成所謂蕭基界面(Schottky Junction)，有效將太陽能成功轉換成氫能。石墨烯是自然界目前已知最薄的材料，只有單原子之碳材，其厚度 ~0.34奈米，約只有頭髮直徑的10萬分之一的厚度。自從其2004年被發現之後，已成為當今相當重要的材料之一，並開啟了二維原子層材料的研究領域。此重要發現之科學家，並於2010年獲頒諾貝爾物理獎。本次研究最大的突破，為利用實驗室所成長的單原子層之石墨烯材料，與具有奈米結構的矽形成具有三維的石墨烯/矽的蕭基界面(Schottky junction)，應用於太陽能產氫。此特殊結構大幅降低了矽的反射率，增加其太陽光吸收效率高達20%，因此增加其產氫效能。此外，雖然石墨烯材料只有單原子層之厚度，但在酸或鹼的電解液中具有非常好的穩定性，能大幅改善過去以矽來做光分解產氫之所遭遇之穩定度問題，在矽表面形成一個好的保護層。此以原子層材料與半導體形成新型的潔淨能源元件，成為未來在太陽能產氫的應用上一個新的平臺。陳俊維教授團隊這項傑出研究不僅順應國際綠能趨勢，與臺灣政府也力推綠能政策相符，且相當具有商業發展價值。此結果於日前登上能源研究頂尖期刊Advanced Energy Materials，並被獲選為當期之封底。
「尖端晶體材料開發及製作計畫」(Taiwan Consortium of Emergent Crystalline Materials (TCECM)) 是科技部有鑑於先進材料是科技發展之根本，長年投入資源扶植臺灣在新穎材料的開發，所建立之研究平臺。近年來在基礎科學研究與產業相關應用，有相當豐碩之成果。
發表論文：Creation of three-dimensional textured graphene/Si Schottky junction photocathode for enhanced photoelectrochemical efficiency and stability, Advanced Energy Materials, 1901022, (2019) 網址：https://doi.org/10.1002/aenm.201901022
研究成果聯絡人
陳俊維特聘教授
國立臺灣大學材料科學與工程學系（所）
電話：02-33665205
Email：chunwei@ntu.edu.tw
Press Release
Feb. 12, 2020
Ultrathin atomic layer materials for efficient solar to hydrogen generation
Under long-term supporting from Ministry of Science and Technology (MOST), Taiwan, the research team of “Emergent Renewable Energy for Next Generation” in Taiwan have recently reported an innovative development on the renewable energy research of “solar-to-hydrogen” generation based on ultrathin atomic layer material of “graphene”. This cross-university research team is led by Prof. Chun-Wei Chen (National Taiwan University), Prof. Bing-Joe Huang (National Taiwan University of Science and Technology), Prof. Di-Yang Wang (Tunghai University), under the support of focused-project called Taiwan Consortium of Emergent Crystalline Materials (TCECM), MOST.
As the issue of global warming has become the most critical issue for mankind in this century, the development of renewable energy to minimize carbon pollution has become the feasible solution. Although solar cells have been widely used to generate electricity directly from the sun, however, the critical issue for solar cells is that the solar energy cannot be used at night or cannot be stored or transported like the fuels of gas or oil we are using daily. One possible solution is to use photo-electrochemical (PEC) conversion for direct solar-to-hydrogen (H2) production, which can split the water into hydrogen and oxygen by using sunlight at semiconductor/electrolyte interfaces and has drawn attention as an environmentally friendly technology for clean energy. The development of cheap and durable photoelectrodes for water splitting is a fundamental challenge in hydrogen production. Silicon (Si) is a feasible commercial PEC material because it is an existing semiconductor for industry,. However, large reflection and poor stability of conventional Si wafer at electrolytes limits the efficiency and stability of the PEC hydrogen production.
“Graphene”, which comprises only a single-atom-thick plane of carbon atoms arranged in a honeycomb lattice, exhibits promising electronic and optoelectronic properties attributed to its unique two-dimensional (2D) energy dispersion. It has a thickness of ~0.34 nm which is about 1/100,000 of the radius of a human hair is the thinnest material existing in nature. Inspired by its excellent carrier transport, high transparency and superior corrosion protection due to its chemical inertness of graphene, the research team demonstrated an innovative design of PEC device based on a graphene/Si Schottky junctions for promising and stable H2 production. They developed a novel method to for water splitting or solar-to-fuel conversion based on that the formation of graphene/Si Schottky junctions with a 3D architecture which significantly improved the performance and durability of Si-based photo-electrochemical systems. The result has been recently published in the prestigious journal in energy research field of “Advanced Energy Materials” and was selected as the back cover of the issue.
Media Contact
Professor Chun-Wei Chen
Department of Materials Science and Engineering, National Taiwan University
TEL: 02-33665205
Email：chunwei@ntu.edu.tw
Dr. Ting-Yang Kuo
Department of Natural Sciences and Sustainable Development,
Ministry of Science and Technology
TEL: 02-27377465
Email: tykuo@nstc.gov.tw
