Banca de DEFESA: JUAN RAFAEL GOMEZ QUISPE
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.DISCENTE : JUAN RAFAEL GOMEZ QUISPE
DATA : 19/12/2022
HORA: 14:00
LOCAL: Sala 302 do Bloco B do Campus de Santo André da Universidade Federal do ABC
TÍTULO:
Water adsorption stability on (110) and (101) surfaces.
PÁGINAS: 95
RESUMO:
Lead acid batteries (LABs) are one of the main technological innovations in 20th-century energy storage. However, to this day, LABs dominate the global battery market due to their high efficiency, safety, recyclability, and low cost. LABs have some disadvantages, such as corrosion in the current collector, sulphation in the electrodes, degradation of the active material, and water loss, the latter being one of the most critical. The water loss in LABs can be studied through the interaction of the active material and the H2O molecules. The active material is made up of a mixture of spongy Pb, α−PbO2, and β−PbO2, the latter being in a higher percentage. β−PbO2 has a tetragonal crystalline phase, with surfaces (110) and (101) being the most stable and reactive. In this work, density functional theory (DFT) and experimental methods (cyclic voltammetry) are used to study the water adsorption modes and hydrogen-oxygen evolution processes, respectively. Quantum Espresso computational package is used to calculate the (101) and (110) surfaces stability and reactivity of the β−PbO2 and β−PbO2 − OX (with reticular oxygen). The results indicate high thermodynamic stability and reactivity of the (101) surface compared to the (110) surface. Molecular and dissociative adsorption modes, promoted by the strong influence of reticular oxygen (OX), are observed on the (101) and (110) surfaces, respectively. Additionally, the potentiostatic pulse method was used to synthesize β − PbO2 thin films on a glass/Au substrate. The XRD and SEM results confirm the homogeneous electrodeposition of β − PbO2 on the substrate. The cyclic voltammetry results indicate the presence of oxygen and hydrogen evolution reactions, apart from the typical β−PbO2 sulfation and desulfation processes.
MEMBROS DA BANCA:
Presidente - Interno ao Programa - 2226644 - LUCAS ALMEIDA MIRANDA BARRETO
Membro Titular - Examinador(a) Interno ao Programa - 1676360 - ANA MELVA CHAMPI FARFAN
Membro Titular - Examinador(a) Interno ao Programa - 1282172 - ROBERTO GOMES DE AGUIAR VEIGA
Membro Titular - Examinador(a) Externo ao Programa - 1309493 - PEDRO ALVES DA SILVA AUTRETO
Membro Suplente - Examinador(a) Interno ao Programa - 1838179 - KATIA FRANKLIN ALBERTIN TORRES
Membro Suplente - Examinador(a) Externo ao Programa - 1734912 - ROOSEVELT DROPPA JUNIOR