School of Physics and Advanced Centre of Research in High Energy Materials, University of Hyderabad, Hyderabad 500046, India.
Nanoscale. 2016 Jun 7;8(21):11194-201. doi: 10.1039/c6nr02572b. Epub 2016 May 16.
The transmission electron microscope electron-beam (TEM e-beam) as a material modification tool has been demonstrated. The material modification is realised in the high-resolution TEM mode (largest condenser aperture, 150 μm, and 200 nm spot size) at a 200 keV beam energy. The Cu2(OH)3NO3 (CHN) nanoflakes used in this study were microwave solution processed that were layered single crystals and radiation sensitive. The single domain CHN flakes disintegrate into a large number of individual CuO crystallites within a 90 s span of time. The sequential bright-field, dark-field, and selected area electron diffraction modes were employed to record the evolved morphology, microstructural changes, and structural transformation that validate CHN modification. High-resolution transmission electron microscopy imaging of e-beam irradiated regions unambiguously supports the growth of CuO nanoparticles (11.8(3.2) nm in diameter). This study demonstrates e-beam irradiation induced CHN depletion, subsequent nucleation and growth of nanocrystalline CuO regions well embedded in the parent burnt porous matrix which can be useful for miniaturized sensing applications. NaBH4 induced room temperature reduction of CHN to elemental Cu and its printability on paper was also demonstrated.
透射电子显微镜电子束（TEM e-beam）已被证明是一种材料改性工具。在高分辨率 TEM 模式下（最大聚光镜孔径为 150 μm，光斑尺寸为 200 nm），在 200 keV 的电子束能量下实现了材料改性。本研究中使用的 Cu2(OH)3NO3 (CHN) 纳米薄片是通过微波溶液处理得到的层状单晶和辐射敏感材料。单个畴 CHN 薄片在 90 秒的时间内分解成大量单个的 CuO 微晶。采用明场、暗场和选区电子衍射模式连续记录演变形态、微观结构变化和结构转变，以验证 CHN 的修饰。电子束辐照区域的高分辨率透射电子显微镜成像明确支持 CuO 纳米粒子（直径为 11.8(3.2)nm）的生长。本研究表明，电子束辐照诱导 CHN 耗尽，随后在母体烧焦多孔基质中形成纳米晶 CuO 区域的形核和生长，这对于小型化传感应用可能是有用的。还证明了 NaBH4 诱导 CHN 在室温下还原为元素 Cu 及其在纸张上的可印刷性。
