Stacking of high aspect-ratio molybdenum disulfide (MoS2) monolayers using sequential electrochemical thinning

• Grant number: 24/15128-7
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: March 01, 2025
• End date: February 28, 2029
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Murilo Santhiago
• Grantee: Isaque Augusto Aragão Feitosa
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovação (Brasil). Campinas , SP, Brazil
• Associated research grant: 23/17576-4 - Controlled generation of chemical defects on the basal plane of molybdenum disulfide (MoS2), AP.R

Abstract

Molybdenum disulfide (MoS2) is a lamellar material whose properties can be modulated according to interest and application. Currently, there is a incessant search to control monolayer stacking in a orchestrated way to obtain three-dimensional (3D) structures. However, the routes proposed so far leave adsorbed impurities on the monolayer and the stacking process in conducted using low aspect-ratio monolayers, thus limiting the adjustment of electrocatalytic properties in the basal plane region. This region, which represents the largest surface area of the material, is relatively inert. Therefore, to activate the basal plane, a series of methods have been proposed to generate defects in the form of sulfur vacancies and/or active edges in the monolayer. However, the generation of edge-type defects with high spatial resolution in the basal plane still represents a challenge due to the types of routes used, which in their vast majority do not allow refined control in the insertion of defects. In this project we aim to develop a new assembling method of 3D structures via stacking of high aspect-ratio monolayer by monolayer and control the insertion of defects in the basal plane to adjust the electrocatalytic activity of the material. Upon overcoming this challenge, it will be possible to have a better understanding of the interface in the region of the defects formed in the basal plane and how these defects impact the electrocatalytic activity of the material. As a proof of concept, we will measure the activity of the monolayers and the stacked 3D structures towards the hydrogen evolution reaction.