Two-dimensional Mo<sub>1.33</sub>C MXene with divacancy ordering prepared from parent 3D laminate with in-plane chemical ordering.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 28440271.
- Also identified by DOI 10.1038/ncomms14949 and PMC identifier 5413966.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The exploration of two-dimensional solids is an active area of materials discovery. Research in this area has given us structures spanning graphene to dichalcogenides, and more recently 2D transition metal carbides (MXenes). One of the challenges now is to master ordering within the atomic sheets. Herein, we present a top-down, high-yield, facile route for the controlled introduction of ordered divacancies in MXenes. By designing a parent 3D atomic laminate, (Mo<sub>2/3</sub>Sc<sub>1/3</sub>)<sub>2</sub>AlC, with in-plane chemical ordering, and by selectively etching the Al and Sc atoms, we show evidence for 2D Mo<sub>1.33</sub>C sheets with ordered metal divacancies and high electrical conductivities. At ∼1,100 F cm<sup>-3</sup>, this 2D material exhibits a 65% higher volumetric capacitance than its counterpart, Mo<sub>2</sub>C, with no vacancies, and one of the highest volumetric capacitance values ever reported, to the best of our knowledge. This structural design on the atomic scale may alter and expand the concept of property-tailoring of 2D materials.