Effect of PVP surfactant on the synthesis of CuO nanoribbons by the chemical reduction method

This work developed a simple and time-dependent method to synthesize CuO nanoribbons. For this, the concentration of the precursor salt (CuCl2), surfactant (PVP), and reaction times were varied, keeping constant the reducing agent (NaBH4). SEM, TEM, XRD, and EDS characterized CuO ribbon-like particles' morphology, chemical composition, and structure. SEM studies confirmed that CuO nanoribbons appear after three weeks of reaction aging by mixing CuCl2 (17 mM), NaBH4 (26 mM), and PVP (1.6 mM). The nanoribbons have a relatively low aspect ratio of 2 to 3 µm long and around 60 nm wide. XRD and TEM confirmed the monoclinic structure of the CuO nanoribbons. SEM micrographs also indicated that as the salt concentration decreases to 10 mM, the size of the products decreases, and nanosheet-like nanostructures with lengths less than 1 μm and thicknesses of 100 nm are formed. PVP was found to have a great influence on the morphology of the nanostructures. For example, low amounts of PVP increase particle oxidation, easily driving the formation of CuO nanoribbons. At the same time, larger amounts stabilize the formation of Cu2O octahedral particles.