Vacancy Associates Promoting Solar-Driven Photocatalytic Activity of Ultrathin Bismuth Oxychloride Nanosheets

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• 作者：Meili Guan ; Chong Xiao ; Jie Zhang ; Shaojuan Fan ; Ran An ; Qingmei Cheng ; Junfeng Xie ; Min Zhou ; Bangjiao Ye ; Yi Xie
• 刊名：The Journal of the American Chemical Society
• 出版年：2013
• 出版时间：July 17, 2013
• 年：2013
• 卷：135
• 期：28
• 页码：10411-10417
• 全文大小：454K
• 年卷期：v.135,no.28(July 17, 2013)
• ISSN：1520-5126

文摘

Crystal facet engineering of semiconductors is of growing interest and an important strategy for fine-tuning solar-driven photocatalytic activity. However, the primary factor in the exposed active facets that determines the photocatalytic property is still elusive. Herein, we have experimentally achieved high solar photocatalytic activity in ultrathin BiOCl nanosheets with almost fully exposed active {001} facets and provide some new and deep-seated insights into how the defects in the exposed active facets affect the solar-driven photocatalytic property. As the thickness of the nanosheets reduces to atomic scale, the predominant defects change from isolated defects V_Bi^{鈥?/sup> to triple vacancy associates V_Bi鈥?/sup>V_O鈥⑩€?/sup>V_Bi鈥?/sup>, which is unambiguously confirmed by the positron annihilation spectra. By virtue of the synergic advantages of enhanced adsorption capability, effective separation of electron鈥揾ole pairs and more reductive photoexcited electrons benefited from the V_Bi鈥?/sup>V_O鈥⑩€?/sup>V_Bi鈥?/sup> vacancy associates, the ultrathin BiOCl nanosheets show significantly promoted solar-driven photocatalytic activity, even with extremely low photocatalyst loading. The finding of the existence of distinct defects (different from those in bulks) in ultrathin nanosheets undoubtedly leads to new possibilities for photocatalyst design using quasi-two-dimensional materials with high solar-driven photocatalytic activity.}