Novel W₃AlB₂ and V₃AlB₂ MAX boride phases and their transformation into W₃B₂ and V₃B₂ MXenes

Owing to their superior electrical conductivity, mechanical, and electrocatalytic characteristics, two-dimensional (2D) MXenes and MBenes with sandwich-like structures produced from layered MAX and MAB phases have garnered interest recently. In particular, boride-MXenes' extensive research in energy storage and electrocatalytic applications would support a bright future. However, research into boride-MXenes is only beginning, and many expected properties and uses remain unexplored. Here, we use density functional theory (DFT) to investigate two novel W₃AlB₂ and V₃AlB₂ hexagonal MAX phase borides (simply MAX borides), and their transformation into W₃B₂ and V₃B₂ MXenes. Elastic stability, dynamic stability, and competitive enthalpy of formation were used to regulate the hexagonal MAX borides' stability, synthesis, and exfoliation into 2D MXenes. The three-phase stability requirements of DFT predictions show that W₃AlB₂ and V₃AlB₂ hexagonal MAX borides and their 2D MXenes are stable and may be experimentally synthesized. These results further demonstrate the metallic properties of 2D W₃B₂ and V₃B₂ MXenes, which are very sought for Li-ion batteries (LIBs) and electrocatalytic applications. The elastic and thermodynamic properties of W₃AlB₂ and V₃AlB₂ hexagonal MAX borides are also estimated via DFT calculations. These research results could pave the way for uncovering novel MAX phases and MXenes, which are important for developing novel 2D nanomaterial advancements.