Journal
ACS APPLIED MATERIALS & INTERFACES
Volume 13, Issue 41, Pages 49163-49171Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acsami.1c13607
Keywords
potassium-mediated oxidation; anisotropic etching; one-dimensional etching; self-running droplet; molybdenum disulfide
Funding
- Institute for Basic Science [IBS-R019-D1]
Ask authors/readers for more resources
This study reveals the role of potassium ions in the oxidation of TMDs and proposes a novel anisotropic etching mechanism driven by self-running oxide droplets. The research demonstrates that potassium-mediated oxidation of MoS2 leads to the formation of K-intercalated hexagonal-phase molybdenum oxides, while orthorhombic-phase oxides are formed in the absence of potassium ions.
Preparation of edge-rich two-dimensional (2D) transition metal dichalocogenides (TMDs) has been actively investigated with the aim to improve their electrical and catalytic properties. Here, we elucidate the role of potassium ions in oxidation of TMDs and suggest a consequent novel anisotropic etching mechanism driven by self-running oxide droplets. We discover that potassium-mediated oxidation of MoS2 leads to the formation of K-intercalated hexagonal-phase molybdenum oxides (h-KxMoO(3)), whereas orthorhombic-phase oxides are formed in the absence of potassium ions. Metastable h-KxMoO(3) appears to have decomposed into oxide droplets at higher temperature. Self-running of the oxide droplets leads to layer-by-layer anisotropic etching of MoS2 along the armchair direction. The motion of the droplets appears to be triggered by the surface energy instability between the oxide droplets and the underlying MoS2 layer. This study opens new possibilities to design and manufacture novel edge-rich 2D TMDs that do not follow the equilibrium Wulff shape by modulating their oxidation with the assistance of alkali metals and also offers fundamental insights into the interactions between nanodroplets and 2D materials toward edge engineering.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available