水裂解

水裂解

水裂解

水裂解科技是一種運用化學反應將水 (H2O) 分解成氧氣和氫氣的程序。有效率的水裂解作用可透過各種不同的科技來進行,例如電解、光合作用、光電化學、光催化、輻射分解、光生物學和熱解作用等等。高度均勻的原子層沉積 (ALD) 經證實對於最佳化槽效率而言格外重要,最新的成就則著重於在較低反應溫度下運用奈米顆粒和薄膜觸媒來裂解水。符合經濟且有效率的水裂解,是作為替代能源選項之一的氫氣生成的關鍵成分。這個領域的相關研究將探索並檢驗移轉至氫經濟的可行性。

水的光氧化作用

原子層沉積 (ALD) 技術可用來製作適用於晶圓裂解的高表面積結構。高表面積傳導和透明架構的產製是為了水的光氧化作用(水裂解)而開發。

運用 Savannah® S200 的原子層沉積 (ALD) 薄膜會使用 ITO 和 Fe2O3 的曝光模式技術在反蛋白石結構上沉積,藉此產生高表面積奈米結構。

原子層沉積 (ALD) 對水裂解的優勢

  • 在 3D 奈米結構上呈現絕佳的勻稱性
  • 高品質的無針孔薄膜
  • 提供了奈米層疊和摻雜薄膜
  • 各式各樣的功能性材料,包含 TCO、氧化鐵、絕緣體

 


水的光氧化作用之特定高表面積透明與傳導架構。氧化鐵 Fe2O3、ITO 和 SiO2 會透過原子層沉積 (ALD) 在反支架結構上沉積。參考資料:Riha, S. C, et al.. Acs Appl Mater Inter 5, 360–367 (2013)。

薄膜

  • 運用 InCp、TDMASn 和 O3 的銦錫氧化物 (ITO)
  • 運用 FeCp2 和 O3 的二茂鐵 (Fe2O3)

結果

  • 運用原子層沉積 (ALD) 技術,製作出適用於水裂解的高度透明、大範圍表面面積奈米層疊。
  • 水氧化作用開始會位移 -200 mV,而光電流則為 1.53 V,對比可逆氫電極則為三倍(與平光陽極相較之下)。

 

綠光照射下,水的氧化作用(透過在 Fe2O3 中的 Ti 取代作用)

運用 Ti 合金來改善超薄(6 奈米厚)赤鐵礦的轉換效率,特別是綠色光子產生的孔洞收集效率(500 – 600 奈米)。在此研究中,Savannah® S200 則被用來沉積 TiO2 與 Fe2O3 這兩種薄膜。

 


Fe2O3 的鈦合金通常會增加以提升水之光電化學氧化的觸媒利用率。 參考資料:Kim, D. W. et al. Greenlighting Photoelectrochemical Oxidation of Water by Iron Oxide. ACS Nano 141203161851003 (2014).

結果

  1. 超薄 Fe2O3 中的 Ti 取代作用可增加表面侷限性孔洞的生命期。
  2. 在經過 Ti 取代作用的薄膜內,可觀察到提升的光電流效能。
  3. 觀測到增強的吸收光子─電子效率 (APCE),特別是在 500 – 600 奈米的範圍內。
  4. 光學吸收方面則未觀察到任何變化。

 

參考資料 - 在 Veeco CNT 原子層沉積 (ALD) 平台上完成的最新出版品

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