Pseudocapacitive Reaction Kinetics: Phosphotungstic Acid/Reduced Graphene Oxide in Acidic Medium.

• Grant number: 23/07179-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2023
• End date: June 30, 2024
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Fritz Cavalcante Huguenin
• Grantee: Serena Nogueira Cesario
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The adsorption/desorption reactions of protons in pseudocapacitors formed by reduced graphene oxide (rGO)/phosphotungstic acid (PW12) will be investigated in this study. These composites exhibit a high energy storage capacity. rGO-PW12 shows promising potential as a high-performance supercapacitor, as PW12 has the ability to anchor and form clusters on rGO with a high surface area, facilitating proton access to electroactive sites. Additionally, a kinetic model developed by the research group will be employed, enabling its application to porous electrodes and allowing for the determination of rate constants, coverage degree, and diffusion coefficients through electrochemical impedance spectroscopy. The model enables the determination of physicochemical parameters related to electrochemical activity, paving the way for structural modifications of the material to increase its charge capacity.