Banca de DEFESA: HUGO GAJARDONI DE LEMOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : HUGO GAJARDONI DE LEMOS
DATA : 30/03/2020
HORA: 14:00
LOCAL: Auditório, 8º andar, Bloco B, Campus SA da Fundação Universidade Federal do ABC, localizada na Avenida dos Estados, 5001, Santa Terezinha, Santo André, SP
TÍTULO:

Investigation of nanocomposite electrodes for dye-sensitized solar cells

PÁGINAS: 150
RESUMO:

The fabrication of efficient a and low-cost electrodes is a highlighted topic for the development of advanced dye-sensitized solar cells (DSSCs). In the first part of this thesis, water-dispersible polyaniline/graphene oxide (PANI-GO)-based CEs was developed. This CE was straightforwardly prepared by deposition of the nanocomposite dispersion onto FTO substrate. The aqueous dispersions of PANI-GO nanocomposites were prepared by two different routes: simple physical mixture of PANI and GO, and in-situ polymerization of aniline in GO aqueous dispersion. DSSC assembled with emeraldine salt polyaniline (PANI-ES)-based CE generated current density (J_sc) of 12.34 mA/cm² and power conversion efficiency (PCE) of 5.18%, which is comparable to the device prepared with Pt-based CE (PCE of 5.24%). The addition of GO is found to increase the J_sc to 13.04 mA/cm² and the fill factor to 68% in CE containing 0.45 wt% of GO (in respect to aniline during synthesis) where the PCE is boosted to 6.21%, which is about 20% higher than Pt-based CE. The investigation of both morphological features and spectroscopic properties showed that PANI-GO nanocomposites prepared by in-situ route have dissimilar protonation and oxidation states when compared with those prepared by physical mixture route. These results give insights into the role of GO in tuning PANI chemical and physical properties in addition to provide a simpler and more efficient methodology for the synthesis of new CEs for DSSCs. In the second part of the Thesis, a simple and scalable methodology was carried out to prepare photoanode by the addition of Ti₃C₂T_x MXenes into the TiO₂ nanoparticulate paste. The incorporation of only 0.075 wt% of the MXene 2D compound (with respect to the TiO₂) resulted in an increase of J_sc from 10.25 mA/cm² (bare photoanode) to 12.66 mA/cm² and boosted the PCE from 5.22% to 6.17% (an improvement of about 18% of DSSC PCE). These results indicate that MXene nanostructures work as an efficient pathway for photogenerated electrons from the dye through the mesoporous structured photoanode.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1671292 - SYDNEY FERREIRA SANTOS
Membro Titular - Examinador(a) Interno ao Programa - 1761120 - DANILO JUSTINO CARASTAN
Membro Titular - Examinador(a) Interno ao Programa - 1671688 - ANDRE SARTO POLO
Membro Titular - Examinador(a) Externo ao Programa - 1760410 - JEVERSON TEODORO ARANTES JUNIOR
Membro Titular - Examinador(a) Externo à Instituição - CARLOS FREDERICO DE OLIVEIRA GRAEFF - UNESP
Membro Suplente - Examinador(a) Interno ao Programa - 1760527 - FLAVIO LEANDRO DE SOUZA
Membro Suplente - Examinador(a) Externo ao Programa - 1838179 - KATIA FRANKLIN ALBERTIN TORRES
Membro Suplente - Examinador(a) Externo ao Programa - 2347767 - MATHILDE JULIENNE GISELE CHAMPEAU FERREIRA
Membro Suplente - Examinador(a) Externo à Instituição - FERNANDO JOSEPETTI FONSECA - USP