Development of graphene-modified gas diffusion electrodes for the degradation of caffeine in synthetic and real water samples

• Grant number: 25/11228-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2025
• End date: July 31, 2026
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Marcos Roberto de Vasconcelos Lanza
• Grantee: Heloisa Nicoletti
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 22/12895-1 - Advanced processes for the degradation of emerging pollutants: catalytic materials, electroanalytical sensors and scientific dissemination, AP.TEM

Abstract

Environmental contamination by emerging contaminants, such as caffeine, has become a significant problem, requiring the development of effective technologies for their removal. Advanced Oxidation Processes (AOPs), especially electrochemical processes, stand out due to the generation of reactive oxygen species, promoting the degradation of pollutants in a sustainable manner. This project aims to develop gas diffusion electrodes (GDEs) based on graphene and/or Printex-L6 carbon for the in situ electrochemical generation of hydrogen peroxide (H¿O¿), applied to the degradation of caffeine in aqueous media. In this study, in addition to the electrode material, operational parameters including current density and pH will be optimized for H¿O¿ production. The electrodes produced will be electrochemically characterized using the rotating ring-disk electrode (RRDE) technique to determine the materials' selectivity for H¿O¿ generation via the 2-electron pathway, and physically characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, and contact angle measurements to clearly characterize and differentiate the materials. Based on the results obtained, it will be possible to select the best condition by evaluating energy consumption and hydrogen peroxide production. Caffeine degradation will be analyzed in potassium sulfate solution and river water using High-Performance Liquid Chromatography (HPLC). Finally, this project will contribute to the development of new alternatives for gas diffusion electrode production, further expanding sustainable approaches for the treatment of effluents containing emerging contaminants, demonstrating the potential of electrochemical degradation through advanced oxidation processes.