Iodinated SnO2 Quantum Dots: A Facile and Efficient Approach To Increase Solar Absorption for Visible-Light Photocatalysis

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• 作者：Pu Li ; Yong Lan ; Qian Zhang ; Ziyan Zhao ; Tonu Pullerits ; Kaibo Zheng ; Ying Zhou
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：May 5, 2016
• 年：2016
• 卷：120
• 期：17
• 页码：9253-9262
• 全文大小：613K
• 年卷期：0
• ISSN：1932-7455

文摘

Efficient visible-light-driven photocatalysis can be achieved over conventional wide band gap semiconductor, in which iodinated SnO₂ quantum dots (QDs) are synthesized via hydrolysis of crystalline SnI₄ in the absence of any additives or templates. The formation of SnO₂ QDs reveals a wide preparation window and a very fast growth rate in minute scale. The iodine species may only exist on the surface of SnO₂ QDs, which can be completely removed through heat treatment. SnO₂ QDs reveal the light absorption in visible range which increases the limited optical absorption of bulk SnO₂. Notably, the iodination can further enhance the visible light absorption due to the formation of band tail states. Therefore, iodinated SnO₂ QDs exhibit significantly enhanced visible-light-driven photocatalytic activity toward degradation of rhodamine B and oxidation of NO in ppb level. Time-resolved spectroscopic studies reveal that the iodine species in QDs can not only server to passivate the surface traps to prolong the lifetime of the excited states when excited above the band gap, but they can also effectively absorb visible light and generate enhancement for photocatalytic reactions. The present study highlights the surface modification of wide band gap semiconductor for exploring efficient visible-light-active photocatalysts.