• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Applied Surface Science >Photocatalytic degradation of Rhodamine-B dye by stable ZnO nanostructures with different calcination temperature induced defects
【24h】

Photocatalytic degradation of Rhodamine-B dye by stable ZnO nanostructures with different calcination temperature induced defects

机译：不同煅烧温度引起的缺陷的稳定ZnO纳米结构对罗丹明B染料的光催化降解

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

For developing ZnO as an efficient photocatalyst it needs to embrace a suitable architecture to promote simultaneous maximum photon absorption and minimum charge carrier recombination. In this regard, presently ZnO nanoparticle and nanorod morphologies with embedded pit like structures possessing enriched surface defects, as demonstrated by X-ray diffraction as well as electron microscopic studies, have been prepared using a rapid one-pot co-precipitation technique. Further characterization by electron paramagnetic resonance (EPR), Raman and PL spectroscopy reveal the origin of bulk and surface defects within the nanostructures. Prominent EPR signals with different g-factors e.g., g = 1.93, 1.97, 2.01 etc., indicate EPR-active defect regions on the bulk and surface of the material. These defect states lower the fast recombination of electron and hole, increase charge transport and accelerate the photocatalytic activity. In the present study most efficient ZnO nanostructures have been obtained at calcination temperature (T-C) similar to 500 degrees C. Formation of metallic zinc through surface reduction of Zn2+ centers promotes narrowing of the optical band gap and endorses efficient absorption of light, additionally via enhanced surface area of the pitted structures. These surface defects reduce recombination of the photogenerated charge carriers and enhance photo-degradation efficiency to similar to 97.75% and rate constant to similar to 0.042 min(-1) under the exposure of UV light.
机译：为了将ZnO开发为有效的光催化剂，它需要采用合适的结构来促进同时最大的光子吸收和最小的载流子重组。在这方面，目前已经使用快速一锅共沉淀技术制备了具有嵌入的坑状结构且具有丰富的表面缺陷的ZnO纳米颗粒和纳米棒形态，如通过X射线衍射和电子显微镜研究所证实的那样。通过电子顺磁共振（EPR），拉曼光谱和PL光谱进行的进一步表征揭示了纳米结构中整体和表面缺陷的起源。具有不同g因子（例如g = 1.93、1.97、2.01等）的突出EPR信号表示材料的主体和表面上具有EPR活性的缺陷区域。这些缺陷状态降低了电子与空穴的快速复合，增加了电荷传输并加速了光催化活性。在本研究中，已在接近500摄氏度的煅烧温度（TC）下获得了最有效的ZnO纳米结构。通过减少Zn2 +中心的表面形成金属锌，可促进光学带隙的变窄并支持有效的光吸收，此外还可以通过增强点蚀结构的表面积。这些表面缺陷减少了光生电荷载流子的重组，并在紫外线照射下将光降解效率提高到约97.75％，速率常数提高到约0.042 min（-1）。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号