Carrier Step-by-Step Transport Initiated by Precise Defect Distribution Engineering for Efficient Photocatalytic Hydrogen Generation

详细信息    查看全文

• 作者：Jiewei Chen ; Gaoxiang Wu ; Tianyue Wang ; Xiaodan Li ; Meicheng Li ; Yuanhua Sang ; Hong Liu
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2017
• 出版时间：February 8, 2017
• 年：2017
• 卷：9
• 期：5
• 页码：4634-4642
• 全文大小：629K
• ISSN：1944-8252

文摘

Semiconductor photocatalysts have been widely used for solar-to-hydrogen conversion; however, efficient photocatalytic hydrogen generation still remains a challenge. To improve the photocatalytic activity, the critical step is the transport of photogenerated carriers from bulk to surface. Here, we report the carrier step-by-step transport (CST) for semiconductor photocatalysts through precise defect engineering. In CST, carriers can fast transport from bulk to shallow traps in the defective subsurface first, and then transfer to the surface active acceptors. The key challenge of initiating CST lies in fine controlling defect distribution in semiconductor photocatalysts to introduce the special band matching between the crystalline bulk and defect-controllable surface, moderate bridgelike shallow traps induced by subsurface defects, and abundant surface active sites induced by surface defects. In our proof-of-concept demonstration, the CST was introduced into typical semiconductor TiO₂ assisted by the fluorine-assisted kinetic hydrolysis method, and the designed TiO₂ can exhibit the state-of-the-art photocatalytic hydrogen generation rate among anatase TiO₂ up to 13.21 mmol h^–1 g^–1, which is 120 times enhanced compared with crystalline anatase TiO₂ under sunlight. The CST initiated by precise defect distribution engineering provides a new sight on greatly improving photocatalytic hydrogen generation performance of semiconductor catalysts.