High {001} facets dominated BiOBr lamellas: facile hydrolysis preparation and selective visible-light photocatalytic activity
High {001} facets dominated BiOBr lamellas: facile hydrolysis preparation and selective visible-light photocatalytic activity
复制标题
高{001}面主导的BiOBr片层：易于水解制备和选择性可见光光催化活性
DOI：
10.1039/c3ta11390f
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发表时间：
2013-01-01
影响因子：
11.9
通讯作者：
Wu, Qingsheng
中科院分区：
文献类型：
--
作者：
Zhang, Da;Li, Jing;Wu, Qingsheng
近年来，具有高活性面暴露率的高效光催化纳米晶引起了人们极大的研究兴趣。然而，此类材料的大多数制备需要添加特殊的封端剂（如表面活性剂）或苛刻的反应条件（如水热反应）。在本工作中，通过调节温度和溶剂，在不添加任何表面活性剂或封端剂的条件下，在水解体系中容易地实现了厚度为9 nm至32 nm的BiOBr纳米片的可控合成。当纳米片的厚度从32 nm减小到9 nm时，BiOBr晶体中的{001}晶面（活性晶面）的暴露率从83%增加到94%，沿着增加，可见光下的光催化效率高于罗丹明B（Rh B）。采用SEM、TEM、AFM、DRS和拉曼光谱等方法对所制备的BiOBr纳米片进行了表征。更重要的是，所获得的BiOBr纳米片表现出选择性可见光催化行为，因为对RhB的活性远高于对甲基橙子（MO）或亚甲蓝（MB）的活性。利用电子顺磁共振（EPR）技术对这一现象进行了研究，并探讨了可能的机理。
Efficient photocatalytic nanocrystals with high-ratio exposure of active facets have aroused a great number of research interests in recent years. However, most preparations of such materials need the addition of special capping agents (like surfactants) or harsh reaction conditions (such as hydrothermal reactions). In this work, a controllable synthesis of BiOBr nanosheets with a thickness from 9 nm to 32 nm was easily achieved in a hydrolysis system through adjusting temperature and solvent, without adding any surfactant or capping agents. As the thickness of the nanosheets decreases from 32 nm to 9 nm, the ratio of exposed {001} facets, the active photocatalysis facets in BiOBr crystals, increases from 83% to 94%, along with an increased photocatalytic efficiency over rhodamine B (RhB) under visible-light. Various methods such as SEM, TEM, AFM, DRS and Raman spectroscopy were used to fully characterize the as-obtained BiOBr nanosheets. More importantly, the obtained BiOBr nanosheets exhibit a selective visible-light photocatalytic behavior as the activity over RhB is much higher than that over Methyl Orange (MO) or Methylene Blue (MB). This phenomenon was studied with in situ electron paramagnetic resonance (EPR) measurements and the potential mechanism was explored.