Discovery of hexagonal ternary phase Ti<sub>2</sub>InB<sub>2</sub> and its evolution to layered boride TiB.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31123253.
- Also identified by DOI 10.1038/s41467-019-10297-8 and PMC identifier 6533257.
- 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
M<sub>n+1</sub>AX<sub>n</sub> phases are a large family of compounds that have been limited, so far, to carbides and nitrides. Here we report the prediction of a compound, Ti<sub>2</sub>InB<sub>2</sub>, a stable boron-based ternary phase in the Ti-In-B system, using a computational structure search strategy. This predicted Ti<sub>2</sub>InB<sub>2</sub> compound is successfully synthesized using a solid-state reaction route and its space group is confirmed as P[Formula: see text]m2 (No. 187), which is in fact a hexagonal subgroup of P6<sub>3</sub>/mmc (No. 194), the symmetry group of conventional M<sub>n+1</sub>AX<sub>n</sub> phases. Moreover, a strategy for the synthesis of MXenes from M<sub>n+1</sub>AX<sub>n</sub> phases is applied, and a layered boride, TiB, is obtained by the removal of the indium layer through dealloying of the parent Ti<sub>2</sub>InB<sub>2</sub> at high temperature under a high vacuum. We theoretically demonstrate that the TiB single layer exhibits superior potential as an anode material for Li/Na ion batteries than conventional carbide MXenes such as Ti<sub>3</sub>C<sub>2</sub>.