Banca de QUALIFICAÇÃO: MICHAEL SEGUNDO SENA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : MICHAEL SEGUNDO SENA
DATE: 16/02/2023
TIME: 08:30
LOCAL: https://meet.google.com/ggx-kaua-cgi
TITLE:

Synthesis and characterization of Cs2AgBiBr6/bismuthene halide perovskite composites applied in the photocatalytic reduction of CO2 for the production of solar fuels

KEY WORDS:

halide perovskites, 2D bismuthene, solar fuels, photocatalytic CO2 reduction, CH4 production, charge separation

PAGES: 128
BIG AREA: Engenharias
AREA: Engenharia Química
SUMMARY:

CO2 photocatalytic conversion into value-added fuels through solar energy is a promising way of storing renewable energy while simultaneously reducing the concentration of CO2 in the atmosphere. Lead-based halide perovskites have recently shown great potential in various applications such as solar cells, optoelectronics, and photocatalysis. Even though they show high performance, the high toxicity of Pb2+ along with poor stability under ambient conditions restrains the application of these materials in photocatalysis. In this respect, we developed an in situ assembly strategy to fabricate the lead-free double perovskite Cs2AgBiBr6 on a 2D bismuthene nanosheet prepared by a ligand-assisted reprecipitation method for a liquid-phase CO2 photocatalytic reduction reaction. The composite improved the production and selectivity of the eight-electron CH4 pathway compared with the two-electron CO pathway, storing more of the light energy harvested by the photocatalyst. The Cs2AgBiBr6/bismuthene composite shows a photocatalytic activity of 1.49(±0.16) μmol g–1 h–1 CH4, 0.67(±0.14) μmol g–1 h–1 CO, and 0.75(±0.20) μmol g–1 h–1 H2, with a CH4 selectivity of 81(±1)% on an electron basis with 1 sun. The improved performance is attributed to the enhanced charge separation and suppressed electron–hole recombination due to good interfacial contact between the perovskite and bismuthene promoted by the synthesis method.

COMMITTEE MEMBERS:
Presidente - 2929066 - ANDRE LUIS LOPES MORIYAMA
Interna - 1271737 - CAMILA PACELLY BRANDÃO DE ARAÚJO
Externa ao Programa - ***.567.564-** - YARA FELICIANO GOMES - UFRN
Externa à Instituição - ANDARAIR GOMES DOS SANTOS - UFERSA