Exploring the Origin of High Dechlorination Activity in Polar Materials M2B5O9Cl (M = Ca, Sr, Ba, Pb) with Built-In Electric Field

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• 作者：Xiaoyun Fan ; Zhipeng Wu ; Lichang Wang ; Chuanyi Wang
• 刊名：Chemistry of Materials
• 出版年：2017
• 出版时间：January 24, 2017
• 年：2017
• 卷：29
• 期：2
• 页码：639-647
• 全文大小：649K
• ISSN：1520-5002

文摘

Polar photocatalyst materials usually exhibit ferroelectric characteristics giving rise to spontaneous polarization behavior which works as a driving force for the separation of photogenerated electrons and holes and mitigates the effect of charge recombination. This study shows that the surface potential changes for a polar phtotocatalyst before and after photoirradiation can be used to predict the photocatalytic activities among different phtotocatalysts. We systematically investigated the correlation among the surface properties, crystal structure, electronic band structure, photocatalytic activity, and stability of four B–O and alkaline earth cations containing photocatalysts, M₂B₅O₉Cl (M = Ca, Sr, Ba, Pb). Among the four studied photocatalysts, Ba₂B₅O₉Cl exhibits the greatest changes in the surface potential after photoirradiation and also shows the highest photocatalytic activity for dechlorination of chlorophenols under UV light irradiation. Its photocatalytic activity is about 1.3, 2.8, 4.4, and 15 times those of Ca₂B₅O₉Cl, Sr₂B₅O₉Cl, Pb₂B₅O₉Cl, and P25 samples, respectively. The results support that the photocatalytic activity of the four photocatalysts strongly depends on the spontaneous polarization power. Overall, these findings demonstrate the utility of Kelvin probe force microscopy that can screen for a highly efficient photodegradation materials in the field of photocatalysis.