Two ultrasonic applications for the synthesis of nanostructured copper oxide (II)

Abazar Hajnorouzi

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URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=137460
Date :  2020/02/27
Publish in :    Ultrasonics Sonochemistry
DOI :  https://doi.org/10.1016/j.ultsonch.2020.105020
Link :  http://dx.doi.org/10.1016/j.ultsonch.2020.105020
Keywords :Direct sonoelectrochemistry Ultrasound ablation Copper nanostructures Copper oxide (II) nanostructures FESEM

Abstract :

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In this paper, we present two aspects of the ultrasonic for the synthesis of CuO (II) nanostructures. In the first ultrasound application, we made a copper tip for an ultrasonic probe transducer and used it for electrolysis and ultrasound irradiation processes. This method is named direct sonoelectrochemistry and compares with conventional electrochemistry. CuO (II) nanostructures are obtained after sintering for both direct sonoelectrochemistry method and conventional electrochemistry method. In the second application of ultrasound, the copper nanostructures were generated by the ultrasound ablation method, and then, the heating process was performed for oxidation. The formation of the copper and CuO (II) nanostructures is confirmed by the powder Xray diffraction (XRD), the field emission electron microscopy (FESEM), and transmission electron microscopy (TEM). The results show that the direct sonoelectrochemistry method generates CuO (II) nanostructures 4.2 times more than conventional electrochemistry. The crystallite size in the electrochemistry methods and direct sonoelectrochemistry is 28.44 nm and 26.60 nm, respectively. The direct sonoelectrochemistry way is a very flexible method and parameters in electrochemical, ultrasound, and the relationship between them can play an important role in the process of synthesis of nanostructures. The crystallite size in the ultrasound ablation method is 21.13 nm and 25.23 nm for the copper and CuO (II) nanostructures. The most important advantages of this method are green, fast, and high purity of the produced nanostructures. 1. Introduction Among the oxides of transition metals nanostructures, copper oxide (CuO) is an important semiconducting material with a narrow band gap 1. CuO nanostructures are widely used in various applications such as gas sensing 2,3, super capacitors 4, Li-ion batteries 5, heterogeneous catalyst 6, solar energy 7,8, antimicrobial applications 9. In the past decades, many approaches have been developed for the synthesis of CuO nanostructures, Conventional methods for the preparation of CuO powders include one step solid state reaction at room temperature 10, mechanochemical process 11, sol-gel 12,13, hydrothermal synthetic method 14, magnetron sputtering technique 15, thermal decomposition 16, precipitation method 17, and microwave synthesis 18,19. Among the recent approaches, the synthesis of copper oxide nanostructures with ultrasonic waves is one of the most important. The use of ultrasound is usually in three forms. 1. Sonochemistry method for the synthesis of CuO nanostructures 20–22 In this