The absorption peaks around 1630 cm -1 and 1058 cm -1 can be attributed to the bending vibrations of the O-H bond, combined with the presence of copper atoms . Finally, according to Sagadevan et al. , the frequency peak identified at 520 cm -1 confirmed the presence of CuO NPs, characteristic of Cu-O bond vibrational frequencies. Thus, the IR spectra results suggest the presence of Cu-O bonds, with very characteristic bands and some constitutional water adsorbed on the copper oxide structure, consistent with studies in the literature .