In the past decade,
two-dimensional (2D) transition metal carbides,
nitrides, and carbonitrides (MXenes) have attracted attention and
interest from the scientific community due to their superior mechanical
strength and flexibility, physical/chemical properties, and multiple
exciting functionalities. Among these materials, the ingenious and
effective combination of the mechanical and functional properties
of MXenes provides a promising opportunity for designing flexible
and wearable devices. This review summarizes the recent research progress
in the structural stabilities, mechanical strength and deformation
mechanism, strain-tunable energy storages, and catalytic and thermoelectric
properties along with certain strain modifications and strain-controllable
electronic/topological properties of MXenes from a combined theoretical
and experimental perspective and illustrates their electronic origins.
Taking the design principles as a focus, the theoretical predictions
provide guidance, while the experimental work gives a thorough validation,
thus setting the foundation for the current scientific achievements,
challenges, and prospects in the field of MXenes.