Advanced oxidative processes and electrochemical methodologies for the synthesis of Graphene Quantum Dots

• Grant number: 24/03365-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): July 01, 2024
• Effective date (End): June 30, 2025
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Paola Corio
• Grantee: Anna Clara Jacomassi Ramos
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 22/11983-4 - Spectroscopy signal enhancement: nanomaterials, theory, and computer simulation, AP.TEM

Abstract

Carbon nanomaterials nanoscale dimensions (such as single and multi-walled carbon nanotubes, graphene, fullerene, carbon dots and graphene quantum dots) have important technological applications such as transistors, sensors, and optoelectronic applications. Graphene quantum dots (GQDs) represent the latest form of carbon relevant in all these areas. GQDs are graphene nanoparticles with the size of the order of the order of 20 nm. Such nanomaterials have extremely peculiar optical, electronic, chemical, and biological properties. The photoluminescent (PL) properties of GQDs can be considered one of their most notable characteristics. Due to their PL properties, high surface area, water solubility, low cytotoxicity, and excellent biocompatibility, GQDs have potential applications in various fields of science. Among the applications of GQDs, we can mention drug delivery, sensors for different chemical species and biomolecules, environmental applications (detection and adsorption of heavy metals), pollutants degradation, among others. This research project proposes the study of methodologies for the synthesis of graphene quantum dots (GQDs) through advanced oxidative processes (POAs) and electrochemical methods, as well as the combination of both (electro-Fenton methodology), using different carbon materials as precursors (graphite, graphene, oxidized graphene, coal, among others). Advanced oxidative processes are based on the generation of hydroxyl radicals, which react quickly and indiscriminately with most organic compounds. The electrochemical oxidation process involves the electrochemical cleavage of carbon precursors into GQDs, typically under high redox voltage. In this project, we will seek to investigate correlations between synthesis methodologies, the morphology of the GQDs obtained, their electronic properties and potential applications. Among the main methods for characterizing the obtained materials, we mention Raman spectroscopy, resonance Raman spectroscopy, infrared, fluorescence, X-ray dispersion, electron spectroscopy, and transmission electron microscopy (HR-TEM) and scanning electron microscopy (SEM).