Study of milling parameters on the mechanochemical synthesis of Ag nanoparticles

• Grant number: 22/03996-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2022
• End date: March 31, 2024
• Field of knowledge: Physical Sciences and Mathematics - Chemistry
• Principal Investigator: Paulo Filho Marques de Oliveira
• Grantee: Laura Libório Lemos
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 20/14955-6 - Designing the next generation of advanced multicomponent materials through mechanochemical synthesis, AP.JP

Abstract

Silver nanoparticles (Ag NPs) are known for their bioactivity and catalytic properties. Ag NPs also exhibits a strong localized surface plasm on resonance (LSPR).LSPR is related to the collective oscillation of the electrons at the surface of metallic NPs when excited by incident photos at the resonant frequency. For Ag NPs, this frequency matches within the visible range (for spherical NPs), enabling an enhanced light absorption and scattering, followed by other subsequent events. This appealing feature of metal Ag NPs has attracted particular interest for application in plasmon-enhancedcatalysis and sensing. Despite the great success of solvothermal routes for the synthesis of metal nanoparticles, enabling the control over size and shape, these classical methods are solvent-intensive and faces limitations such as the preparation of the nanomaterials at scale. On the other hand, mechanochemical means, mainly ball milling, have succeed in the solid-state preparation of metal nanoparticles in gram scale in an environmentally friendly framework. It has been noticed that the milling parameters can affect the resulting nanostructures synthetized by the bottom-up approach. The size and morphology of the metal NPs seems to be sensitive on the intensity of the mechanical energy input. However, the is a lack of broader investigation to identify the central milling parameters that controls the NP formation. In the present project, the effect of milling parameters on the bottom-up mechanochemical synthesis of Ag NPs will be studied. The influence of the type of milling device, the ball-to-powder mass ratio, milling frequency and milling time, on the kinetics of NPs formation and on the size and morphology of the resulting AgNPs will be investigated. The NPs will be characterized by Transmission Electron Microcopy (TEM), Power X-ray Diffraction (PXRD) as well as by UV-VIS Diffuse Reflectance Spectroscopy (UV-VIS DRS), taking advantaged from the LSPR excitation of Ag NPs in the visible range. This project represents a step forward in the understanding of the controlled solid-state synthesis of NPs by tuning the mechanochemical conditions.(AU)