Oxidation of Molybdenum-Based Single-Metallic/bimetallic Carbide MXenes in Aqueous Suspensions: Mechanistic Insights.

Molybdenum carbide MXenes have garnered considerable attention in electronics, energy storage, and catalysis. However, they are prone to oxidative degradation, but the associated mechanisms have not been systematically explored. Therefore, the oxidation mechanisms of Mo-based single-metallic/bimetallic carbide MXenes including MoCT, MoTiCT, and MoTiCT in aqueous suspensions were investigated for the first time in this study.

Universal Ligands for Dispersion of Two-Dimensional MXene in Organic Solvents.

Ligands can control the surface chemistry, physicochemical properties, processing, and applications of nanomaterials. MXenes are the fastest growing family of two-dimensional (2D) nanomaterials, showing promise for energy, electronic, and environmental applications. However, complex oxidation states, surface terminal groups, and interaction with the environment have hindered the development of organic ligands suitable for MXenes.

Tunable TiCT MXene-Derived TiO Nanocrystals at Controlled pH and Temperature.

While two-dimensional (2D) TiCT MXene in aqueous dispersions spontaneously oxidizes into titanium dioxide (TiO) nanocrystals, the crystallization mechanism has not been comprehensively understood and the resultant crystal structures are not controlled among three representative polymorphs: anatase, rutile, and brookite. In this study, such control on the lattice structures and domain sizes of the MXene-derived TiO crystallites is demonstrated by means of the oxidation conditions, pH, and temperature (3.0-11.

Mechanism and Kinetics of Oxidation Reaction of Aqueous TiCT Suspensions at Different pHs and Temperatures.

Understanding the oxidation reaction of aqueous TiCT MXene suspensions is very important for fostering fundamental academic studies as well as widespread industrial applications. Herein, we investigated the mechanism and kinetics of the oxidation reaction of aqueous TiCT suspensions at various pH and temperature conditions. Through comprehensive analysis, the mechanism of the chemical oxidative degradation of aqueous TiCT colloids was established.