MBenesAn Emerging 2D Layered Material: Synthesis, DFT Studies, and Application as Electrocatalyst for Hydrogen Evolution Reaction: A Review

MBenes are a relatively new addition to the family of 2-D layered materials and are still in its infancy. Their unique layered structure and remarkable propertiesincluding high electrical conductivity, magnetic properties, mechanical strength, surface functional groups, and abundant active siteshave established them as a rising star in the field of 2-D materials, and their potential use in a plethora of applications has been anticipated. Initially, in 2017, theoretical studies predicted the possible structures of MBenes (M (n)B(2n‑2)), and then experimental synthesis of certain MBenes confirmed their existence, paving the way for further research and development. In this review paper, we have discussed the fundamental aspects of MBenes, including their theoretically predicted crystal structures, stability, chemical compositions, and their synthesis from precursor MAB phases. The challenges currently hindering the progress of MBenes have also been mentioned. In this review, special emphasis is placed on the performance of various MBenes as electrocatalysts for the hydrogen evolution reaction (HER), along with the insights provided by theoretical studies.