微波水熱法製備金屬硫化物粉體及其光化學產氫研究

能源危機與環保問題為本世紀重要的挑戰，乾淨的氫能源成為取代石化燃料的最佳替代能源，使得發展光觸媒來分解水產氫的研究變得很重要，使用光觸媒有效利用太陽能分解水產氫，便是此研究的目標。實驗中使用的ZIS (ZnmIn2S3+m)可見光光觸媒，隨著溫度的上升有助於提升水分解效率，我們調整核殼結構(Coreshell)內部Nanoshell(Ag@Au)的吸收波段至紅外光，將太陽能轉換為熱能，形成光觸媒侷部加熱的效應，最高能有效提升光觸媒的產氫效率達74%。Nanoshell 是由銀與金奈米粒子所組成，在太陽光照射下其具有表面電漿共振效應，使用吸收波長在700 nm 左右的Nanoshell 與光觸媒形成核殼結構後，表面電漿共振能量傳遞給外層的光觸媒，利於電子電洞的分離，提升產氫效率最高可達1.62 倍。我們也改變Nanoshell 上不同SiO2 厚度，觀察光觸媒與Nanoshell 之間的交互作用對於產氫效率的影響，當無SiO2 在兩者之間時，電子會在兩者之間傳遞，而過厚的SiO2 會阻礙表面電漿效應的能量傳遞，而使得光觸媒產氫效率提升幅度下降。將光觸媒與Nanoshell 直接合成核殼結構，可能會有光觸媒過厚或是部分Nanoshell 裸露的情形產生，所以我們嘗試先在ZIS 表面改質，再與 Nanoshell 合成核殼結構，反之，也可以在Nanoshell 表面改質，再與ZIS 合成核殼結構，使得每個Nanoshell 的表面都有均勻分布的ZIS，得到最佳的核殼結構。

關鍵字

微波輔助；金屬硫化物粉體；產氫；核殼結構；光化學

並列摘要

Energy crisis and environmental protection are big challenges of this century. Hydrogen is the most promising replacement for fossil fuels. Therefore, the development of visible-light-driven photocatalysts for water splitting is critical. The purpose of this study is to effectively use photocatalysts to change solar energy into hydrogen energy. We used ZIS (ZnmIn2S3+m) as visible-light-driven photocatalyst. Its water splitting reaction rate increased with the temperature. The absorption of the nanoshells in the coreshell nanoparticles can be adjusted systematically from visible light to IR range making the solar energy into heat and resulted in local thermal effect which can effectively enhance hydrogen evolution to 74%. Because the nanoshell was formed by silver and gold nanoparticles, it had the surface plasmon resonance. Using nanoshells absorbing at 700 nm can transfer enengy to photocatalysts and separated the combination of electrons and holes in photocatalysts making the enhancement of hydrogen evolution to 1.62 times. We also changed the thickness of SiO2 on the nanoshells to observe the interaction between nanoshells and coreshells which might influence the enhancement of hydrogen evolution. When there was no SiO2, electron would transfer between nanoshells and photocatalysts. Thicker thickness of SiO2 might hinder the translation of energy from nanoshells decreasing the enhancement of hydrogen evolution. Making photocatalysts directly into coreshell structures might cause thicker shell or uncovered nanoshells. So we try to mdify the surface of ZIS or mdify the surface of nanoshells and formed coreshell, making uniform distribution of ZIS on nanoshells.

並列關鍵字

Microwave-assisted ； Metal Sulfide Powder ； Hydrogen evolution ； Coreshell ； Photochemistry

參考文獻

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微波水熱法製備金屬硫化物粉體及其光化學產氫研究

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