Hybrid Carbon Architectures with Plasmonic Nanoparticles via Mechanochemistry: Structural Studies and Catalytic Potential

• Grant number: 25/15786-7
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: November 01, 2025
• End date: October 31, 2029
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Paulo Filho Marques de Oliveira
• Grantee: Steffany Luczynski Makara
• 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

The global demand for energy continues to grow, while the effects of greenhouse gases-especially those resulting from the combustion of fossil fuels-have intensified and expanded. These two realities call for an urgent scientific and technological response focused on the development and improvement of clean energy generation technologies. From the perspective of chemical and materials sciences, major contributions involve the development of more efficient materials capable of mediating relevant chemical reactions in a more sustainable manner, such as the production of renewable fuels-for example, hydrogen via water electrolysis-or the fixation of CO¿ and N¿ through different routes, as well as the use of clean energy sources to drive these transformations (solar energy, electricity from renewable sources, among others). Just as clean and renewable energy is sought, the materials used in these chemical transformations must also be prepared under the same principles, in a greener, environmentally safe, and efficient manner. In this context, mechanochemical synthesis has gained prominence and scope both in scientific research and in technological applications, enabling the preparation of advanced materials such as metallic nanoparticles, highly ordered porous structures, metal oxides, and functionalized carbonaceous materials such as graphite, graphene, and carbon nanotubes. This route eliminates the use of solvents and post-synthesis treatments, in addition to allowing fast and, when desired, large-scale production. This doctoral project aims to synthesize Au and Ag metallic nanoparticles directly supported on graphene oxide. The proposed work involves the mechanochemical preparation of these hybrid materials and the evaluation of their electrocatalytic performance in the hydrogen evolution reaction (HER). Au and Ag nanoparticles exhibit plasmonic properties and can be activated by light to enhance catalytic activity, while carbonaceous materials offer high electrical conductivity-a significant advantage in electrochemical applications. The parameters of the mechanochemical synthesis using ball milling will be studied in detail to understand their effects on the final structure of the materials and, consequently, on their catalytic activity. Considering that Au and Ag are not the most efficient catalysts for HER, metals such as Pd, Rh, and Pt will be incorporated into the plasmonic materials. Furthermore, the project involves the study of the local structure of the hybrid materials and their in situ and operando electrochemical activity using X-ray absorption spectroscopy. Techniques such as PDF-XRD and HRTEM will also be employed to investigate the effects of mechanical stress on the structure of graphene oxide and its derivatives. This project will advance both the functionalization of carbonaceous materials directly in the solid state and the understanding of the relationship between structure-often locally disordered and therefore more active-and the catalytic activity of materials obtained via mechanochemical routes, with a focus on the production of high-energy-density molecules.