Transições de fase e funcionalização química em nanoestruturas de MoS2 : aplicações em energias renováveis
Tipo
Dissertação
Data de publicação
2019-12-19
Periódico
Citações (Scopus)
Autores
Santos, Felipe Conceição dos
Orientador
Maroneze, Camila Marchetti
Título da Revista
ISSN da Revista
Título de Volume
Membros da banca
Silva, Cecilia de Carvalho Castro e
Mararigone, Valéria Spolon
Mararigone, Valéria Spolon
Programa
Engenharia de Materiais e Nanotecnologia
Resumo
The eminent scarcity of fuels based on fossil resources, as well as serious
environmental damage arising from their utilization, imposes us a need to search for
more sustainable alternatives in the energy field. The use of hydrogen as a fuel
presents itself as a promising solution, having as a main challenge the substitution of
platinum for catalysts that provides energetic viability to electrochemical technologies.
The transition metal dichalcogenides (TMDs), especially the molybdenum disulfide
(MoS2), is pointed as a potential substitute for the metal catalysts due to the high
catalytic activity observed for MoS2 when presented in the metallic phase (1T).
However, the 1T phase is thermodynamically metastable, and it is essential to develop
strategies to stabilize the metal phase of MoS2 without compromising its catalytic
properties. The present work describes a study of the stability of the 1T’ phase
(distorted metallic) in MoS2 nanostructures prepared by chemical exfoliation with nbutillithium.
Initially it is presented the synthesis of a material with mixed character
(1T’/2H-MoS2) as well as the impact of the presence of semiconducting domains in the
stability of the 1T’ phase and in the material’s catalytic properties. Additionally, surface
chemical functionalization of 1T’-MoS2 with organic molecules were studied as a tool
to promote the metallic phase stabilization. The results indicated that the presence of
semiconducting domains possess a great negative impact both in the 1T’ phase
stability and in the electrocatalytic performance of the material in the hydrogen
evolution reaction (HER). The chemical modification of the surface of MoS2 presented
itself as a pretty efficient strategy to stabilize the 1T’ phase and prevent 1T’-MoS2
oxidation.
Descrição
Palavras-chave
MoS2 , transições de fase , funcionalização química
Assuntos Scopus
Citação
SANTOS, Felipe Conceição dos. Transições de fase e funcionalização química em nanoestruturas de MoS2 : aplicações em energias renováveis. 2019. 56 f. Dissertação (mestrado em Engenharia de Materiais e Nanotecnologia) - Universidade Presbiteriana Mackenzie, São Paulo, 2020.