1T-MoS2催化劑結合矽光電陰極應用於氮氣還原反應

Abstract

哈伯法被廣泛的應用於將大氣中的氮氣轉化為氨。但此過程高溫高壓的反應條件與大量碳排放的釋出，使得開發另一綠色的氨生產方法更為重要。而光電化學氮氣還原反應是一個具有潛力、可替代哈伯法的氨生產方法。 為了提高產氨的效率，使用具有高催化活性的材料是一個重要的關鍵因素。傳統的貴金屬是公認最好的催化物質，但貴金屬的高成本和稀少性使得它的發展與應用受到了很大的限制。近年來，二維材料引起了科學家們對於催化領域的關注。而其中的二硫化鉬因為具有獨特的晶體結構與性質，許多人開始討論它作為催化物的表現。因此，本篇研究主題將會是探討如何提升二硫化鉬於產氨領域的催化能力。 此論文將以1T晶相的二硫化鉬（1T-MoS2）作為研究對象。我們採用簡單的水熱法來合成1T-MoS2的晶體粉末，再以其作為催化劑，進行光電化學的氮氣還原反應。接著在測試電化學性能中，於-0.4V（vs. RHE）的電位下獲得了12.20μg h-1 cm-2的氨產量與22.19%的法拉第效率；在測試光電化學的性能之中，則是於0.2V（vs. RHE）的電位下獲得了18.29μg h-1 cm-2的氨產量與28.57%的法拉第效率。 與單純的電化學反應相比，採用光電化學元件結合太陽能和電力的優點，在正電位下進行氮氣還原反應，不僅提高了產氨的法拉第效率，而且也使氨的產量提高了。The Haber process is widely used to convert nitrogen to ammonia. However, the high temperature and high pressure reaction conditions, and the large amount of carbon emissions in this process make it more important to develop another green ammonia production method. Photoelectrochemical nitrogen reduction reaction is an alternative method to replace the Haber process for ammonia production. To improve the efficiency of ammonia production, the use of materials with high catalytic activity is an important key factor. The traditional precious metals are recognized as the best catalytic materials, but the high cost and rarity of precious metals limit their developments and applications. In recent years, two-dimensional materials have attracted the attention of scientists in the field of catalysis. Among them, molybdenum disulfide has a unique crystal structure and properties, and many people have begun to discuss its performance as a catalyst. Therefore, the theme of this research will explore how to improve the catalytic ability of molybdenum disulfide in the field of ammonia production. This article will take the 1T crystal phase molybdenum disulfide (1T-MoS2) as the research object. We use hydrothermal method to synthesize 1T-MoS2 crystal powder, and then use it as a catalyst for photoelectrochemical nitrogen reduction reaction. In the electrochemical performance test, the ammonia yield of 12.20μg h-1 cm-2 and the Faradaic efficiency of 22.19% were obtained at a potential of -0.4V (vs. RHE). In the photoelectrochemical performance test, the ammonia yield of 18.29μg h-1 cm-2 and the Faradaic efficiency of 28.57% were obtained at a potential of 0.2V (vs. RHE). Compared to the electrochemical reaction, using photoelectrochemical devices to combine the advantages of solar energy and electricity to carry out the nitrogen reduction reaction at a positive potential not only improves the Faradaic efficiency, but also increases the ammonia production.