Use of H₂O₂ for the Morphology Control of Silver Nanostructures

Nanotechnology is a field that has advanced significantly in the last decades. Nanomaterials, as a result of their nanometric dimensions, exhibit unique properties that enhance their technological and biomedical applications. Metallic nanoparticles, like silver nanoparticles (AgNPs), have stood out due to their intrinsic properties, such as the localized surface plasmon resonance, which can be controlled by their size and shape. Thus, in this work, we developed a practical synthetic procedure to obtain AgNPs with controlled morphology. AgNPs were prepared in water by the chemical reduction methodology, using different stabilizers under room temperature or with heating, and sodium borohydride as the reducing agent. The results obtained showed that the AgNPs were successfully prepared, using polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) as the stabilizing agents. The AgNPs' shape could be controlled by the absence or presence of H2O2, forming nanospheres or nanoprisms, respectively. The nanomaterials prepared exhibited colloidal stability with a negative surface charge, and TEM images confirmed their spherical and prismatic morphology. Furthermore, the results showed that the two synthesis conditions, room temperature and heating, afforded AgNPs in spherical and prismatic shapes, however, with temperature the size distribution was lower. Thus, this methodology has the potential to be expanded to other stabilizing agents as a simple and practical method to prepare silver nanostructures with controlled morphology.