Quantum Rate Theory and Pseudocapacitance Phenomena

• Grant number: 25/03273-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: May 01, 2025
• End date: April 30, 2027
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Paulo Roberto Bueno
• Grantee: Edgar Fabian Pinzon Nieto
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Associated research grant: 24/02000-2 - Principles and methods of low energy quantum electrodynamics, AP.TEM

Abstract

The proof of concept that the superpacitance of redox-active monolayers (with a specific capacitance of about 2,000 F/g; measured in a three-electrode setup) is associated with a quantum mechanical phenomenon that involves the correlation of conductance quantum G_0= g_s e^2/h and the quantum capacitance C_q. This relationship between G_(0 )and C_q has been demonstrated previously for redox reaction dynamics, where the presence of electron transfer dynamics within the interface obeys a quantum mechanical rate such as that ¿ = g_s e^2/hC_q = G_0/C_q controls the rate of the reactions in the interface. Based on this simple quantum mechanical principle that explains the origin of the supercapacitive phenomenon through the meaning of C_q states and how they are charged by an associated quantum mechanical resistance proportional to G_0. However, this principle not only applies to interfaces possessing redox-active compounds (for instance, based on metal-oxide frameworks - MOFs), but it also operates in explaining the super capacitance phenomena in non-redox compounds such as those based on carbonaceous structures (for instance, reduced graphene oxide - rGO). It has been demonstrated that both modified MOF and rGO compounds can be individually used as active compounds in symmetric supercapacitor devices. In a hybrid supercapacitor, MOF structures act as cathodes whereas rGOs as anodes. This workplan will focus only on the rGO electrochemical properties to prove that the quantum rate theory within a key rate concept ¿ = g_s e^2/hC_q = G_0/C_q applies to explain the supercapacitance phenomena of rGO. Furthermore, it will be demonstrated that the quantum rate method offers a key spectroscopic methodology for the in-situ characterization of the modifications conducted in rGO compounds.