MBenes: Emerging Two-Dimensional Metal Borides for Multifunctional Energy Storage and Conversion Technologies

Abstract

MBenes, an innovative class of two-dimensional (2D) transition metal borides, have emerged as a game-changer in the realm of advanced energy storage, particularly for next-generation supercapacitors. Derived from MAB phases through selective chemical etching, MBenes exhibit exceptional electrical conductivity, tunable surface functionalities, large theoretical surface areas, and superior mechanical stability, positioning them as superior alternatives to MXenes and other 2D materials. Their unique structural and electrochemical properties, including high specific capacitance, rapid ion diffusion, and robust cycling stability, enable MBenes to address critical challenges in supercapacitor performance, such as low energy density and limited lifespan. Fluorine-free synthesis methods, such as hydrothermal and alkalibased etching, enhance scalability and environmental sustainability, while MBene-based nanocomposites, like MoB@LDH and CrBMg/graphene, leverage synergistic effects for enhanced energy and power density. Beyond supercapacitors, MBenes demonstrate transformative potential in metal-ion batteries, electrocatalysis, gas sensing, carbon capture, and solar-driven systems, underscoring their versatility for sustainable energy solutions. This review comprehensively explores MBenes' synthesis, properties, and applications, highlighting their pivotal role in redefining energy storage paradigms and addressing global sustainability challenges.