Metal oxide nanomaterials, including copper oxide, have attracted great attention due to their unique physical and chemical properties that are dependent on particle size and morphology. In this study, we propose an alternative technique for the synthesis of 2D mesoporous CuO agglomerates that is both efficient and ecological. This technique is based on the use of pulsed spark discharges between copper electrodes immersed in deionized water. Detailed TEM analyses show that the synthesized CuO nanostructures are composed of elementary nanocrystals with sizes in the order of a few nanometers. Assessments of the effects of applied voltage (5 and 20 kV) and discharge pulse width (100 and 500 ns) demonstrate that the latter parameter influences the size and density of nanocrystals in a nanostructure. Moreover, voltage and pulse width may both be used to finely control the direct optical band gap energy of CuO nanostructures between 3.0 and 3.4 eV. The efficient and ecological technique developed in this study produces 2D mesoporous CuO agglomerates that can be readily used in other processes.

中文翻译：

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水中脉冲火花放电选择性合成二维介孔 CuO 团聚体

包括氧化铜在内的金属氧化物纳米材料由于其独特的物理和化学性质而受到极大关注，这些物理和化学性质取决于粒径和形态。在这项研究中，我们提出了一种合成二维介孔 CuO 团聚体的替代技术，该技术既高效又生态。该技术基于在浸入去离子水中的铜电极之间使用脉冲火花放电。详细的 TEM 分析表明合成的 CuO 纳米结构由尺寸为几纳米的基本纳米晶体组成。对施加电压（5 和 20 kV）和放电脉冲宽度（100 和 500 ns）的影响的评估表明，后一个参数影响纳米结构中纳米晶体的尺寸和密度。而且，电压和脉冲宽度均可用于将 CuO 纳米结构的直接光学带隙能量精细控制在 3.0 和 3.4 eV 之间。本研究中开发的高效生态技术产生了二维介孔 CuO 团聚体，可以很容易地用于其他过程。