Fabrication of cuprous oxide nanoparticles by laser ablation in PVP aqueous solution

Abstract

The cuprous oxide nanoparticles have been fabricated through pulsed laser ablation of copper target in PVP aqueous solution. The structure, morphology and composition of the nanoparticles have been characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), highresolution TEM (HRTEM), X-ray photoelectron spectroscopy (XPS) and X-ray excited auger spectra (XAES). The results show that the mean size of the as-prepared in diameter is about 29 nm with a relative narrow size distribution and samples are polycrystal Cu 2 O nanoparticles with a shell of thin layer of amorphous CuO. Furthermore, a possible mechanism for formation of such the cuprous oxide nanoparticles is discussed. We concluded that pulsed laser ablation of copper in liquid is a feasible method for the synthesis of cuprous oxide nanoparticles.

Analysis of the structure, configuration, and sizing of Cu and Cu oxide nanoparticles generated by fs laser ablation of solid target in liquids

“…22,24,26,28 The mechanisms underlying the formation of copper Nps with pulsed laser ablation of a copper solid target in liquids are very complex. Oxidative processes of Cu Nps are complicated since copper has two oxidation states (Cu þ1 and Cu þ2 ) that form stable oxides with different activation energy barriers.…”

“…CuO type oxide of size less than 200 nm was formed in tightly focusing conditions, while Cu 2 O type oxide, of size under 10 nm, appeared for defocusing conditions. Recently, Liu et al 26 used the fundamental wavelength of a Nd:YAG laser to produce 30 nm diameter Cu 2 O Nps from laser ablation of an electrolytic copper plate immersed in PVP. XRD and electron diffraction patterns showed that Cu particles draughtdried at room temperature oxidized completely to Cu 2 O.…”

“…A Cu Nps fabrication technique commonly used by many authors is pulsed laser ablation of solid target in liquids. 22,23,25,26 In these cases, the fundamental or second harmonic wavelength of a Q-switched 10 ns pulsed Nd:YAG laser was used. Tilaki et al 22 produced with this method Cu Nps in water and acetone with sizes around 30 nm and 3 nm, respectively.…”

“…In this sense, optical extinction spectroscopy has demonstrated its ability to size core radius and shell thickness of noble metal Nps through the fitting of the full UV-Vis extinction spectra using Mie's theory 14 together with a conveniently modified metal bulk complex dielectric function that includes the size correction of free and bound electrons contributions. [15][16][17][18][19] During the last years, there has been a lot of research about Cu-Cu oxide nanocomposites [20][21][22][23][24][25][26][27][28] covering different aspects such as fabrication methods, optical properties, and structural analyses. From a general point of view, it can be said that knowledge of the mechanisms responsible for the formation of Cu-Cu oxide Nps is far from complete and may vary with the different conditions under which they were fabricated.…”

“…We discuss our results based on oxidation mechanisms of Nps during the fabrication process as studied by other authors. [20][21][22][23][24][25][26][27][28] …”