Phase transition of Cu2O to CuO nanocrystals by selective laser heating

In this paper, we reported the preparation of CuO nanocrystals by microwave irradiation method. With the aid of suitable surfactants, CuO nanoparticles of uniform size and shape were successfully prepared. The as-prepared nano-products were characterized by different techniques such as Xray diffraction (XRD), Raman scattering, scanning electron microscopy (SEM), which all confirmed the good quality of the product. However, Raman spectra showed some peaks, which were attributed to impurity phases such as Cu2O or Cu(OH)2. Post annealing the samples by laser is a good method to convert these phases into pure CuO. Phase transition was observed in situ by Raman spectroscopy. After laser treatment process, Raman spectra of the samples showed that the nano-product is single phase and the crystal quality of CuO nanocrystal was improved clearly.