開發FeS2-TiO2複合材料並應用在光催化產氫之研究

Abstract

在本實驗中，我們利用溶液合成方法製備出親水性的二硫化鐵奈米晶體(FeS2 NCs)，再與市售的二氧化鈦 (TiO2，Degussa P25)混合，作為複合材料光觸媒，應用在光催化分解水產生氫氣。 實驗中，利用溶液合成法製備出親水性的FeS2，摻雜P25 (TiO2)，進行高溫硫化鍛燒步驟，使FeS2與TiO2能更緊密的結合。所得到的複合材料光觸媒在加入犧牲試劑後進行光照反應(光源：Mercury arc lamp, 強度：400W)，在不同的實驗條件下：光觸媒比例、犧牲試劑、溶液pH值…等，偵測照光後產氫效果，其最佳條件為FeS2-TiO2 (1:1)，犧牲試劑為MeOH/H2O (1:1)，pH值為7，產氫速率為373 mole h-1 g-1。相較於單純P25，產氫速率提升約20倍。更重要的，FeS2-TiO2具有好的光催化產氫效果，主要是因為FeS2材料吸收較TiO2廣，可吸收波長為可見光的部份，進而增加產氫之效率。 在此研究中，我們呈現出以地球含量多且非毒性的二硫化鐵(FeS2)結合二氧化鈦(TiO2)作為複合材料光觸媒，經由硫化步驟優化FeS2-TiO2複合材料，且不須藉由任何貴金屬做助催化劑，就能有效達到分解水的產氫效果。In this work, we demonstrated a new photocatalyst consisting of FeS2 NCs and TiO2 (Degussa P25) nanomaterials for water splitting reaction. For fabricating the photocatalyst of FeS2-TiO2 nanocomposites, first, FeS2 NCs was successfully prepared by solution process and then mixed with TiO2 under sonication reaction. To enhance interface connection between FeS2 and TiO2, a sulfurization process is obtained. For testing hydrogen generation reaction, a 400W mercury arc lamp was used as a light source to trigger the photocatalytic reaction. We found that the catalysts of FeS2-TiO2 (1:1) in the MeOH/H2O (1:1) solution at pH 7, has highest hydrogen production rate of 373 mole h-1 g-1, which is 20 folds of pristine P25 photocatalyst. In this study, we demonstrated that a FeS2-TiO2 nanocomposites catalysts, which is abundant on earth, environment friendly, and economy, achieved an effectively hydrogen production for water splitting because of extending absorbing visible light in comparison with pure TiO2.