Effects of post-annealing treatment on the microstructural evolution and quality of Cu(OH)2 nanowires

A hydrothermal method was used to synthesize Cu(OH)2 nanowires (NWs) in 20 mM of CuSO4 aqueous solution, mixed with 0.015 M NH4OH and 0.5 M NaOH alkaline solution. The morphology (via scanning electron microscopy, (SEM)) of Cu(OH)2 NWs changed into CuO nanostructures as a function of the degree of dehydration, which was affected by the annealing process variables. X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED) analyses were performed to characterize the microstructural features of both the Cu(OH)2-based and CuO-based nanostructures before and after annealing treatment. In addition, photoluminescence (PL) spectroscopy was carried out to investigate the crystalline quality and distribution within the samples indirectly. This study addresses the influences on the microstructural transition of individual Cu(OH)2-based and CuO-based nanostructures.