Synthesis of CuO@ZnO Nanoparticle Core–Shell Formed via Laser Ablation in Liquid for Photocatalytic Applications

This research study specifically examines the CuO@ZnO nanoparticle core–shell colloidal solution that is produced using Nd: YAG laser ablation. The laser used has pulse energies of 900, 700, and 500 mJ, a wavelength of 1064 nm, and repeated pulses of 200. This work demonstrated the characteristics of a colloidal solution containing CuO@ZnO NP core–shell deposited onto Si substrates using the drop-casting process. The TEM, SEM, XRD, and UV–vis spectroscopy techniques were used to investigate the morphological, shape, optical, and structural characteristics of the synthesized CuO@ZnO NP core–shell. The XRD analysis reveals that the CuO@ZnO NP core–shell has sizes ranging from 30 to 93 nm approximately. The nanoparticle core–shell exhibited a combination of spherical and irregular shapes with sizes ranging from 30 to 90 nm. The nanoparticle size appeared to be influenced by the variation in laser pulse energy, as evidenced in SEM pictures. The TEM pictures reveal that the core–shell nanoparticles exhibit a particle size distribution with average sizes of 19, 70, and 30 nm for the nanoparticles produced using laser pulses with energy levels of 900, 700, and 500 mJ, respectively. The TEM pictures also exhibit a dark central region of CuO NPs and a comparatively lighter outside region of the ZnO nanoshell, thereby verifying its core–shell structure. Alteration of the laser energy resulted in a noticeable change in the optical energy band gap in the generated samples. The results of the UV–vis test suggested that a change in the energy of the laser pulse caused a change in the energy gap that ranges from 2.6 to 3 eV. The dye degradation capability of CuO@ZnO NP core–shell has been evaluated using methylene blue (MB), an organic dye. The results indicate that all samples exhibited successful degradation using CuO@ZnO NP core–shell with differentiated activity levels. The blue color of the methylene blue solution vanished within 120 min of exposure to illumination when the CuO@ZnO nanoparticles, generated with a laser energy of 900 mJ, were present. The investigation of CuO@ZnO nanoparticles, synthesized through the use of laser pulse energy, demonstrates its potential as a highly effective substance for water purification.