MXenes/CNTs-based hybrids: Fabrications, mechanisms, and modification strategies for energy and environmental applications

Emerging two-dimensional (2D) layered metal carbide and nitride materials, commonly termed MXenes, are increasingly recognized for their applications across diverse fields such as energy, environment, and catalysis. In the past few years, MXenes/carbon nanotubes (CNTs)-based hybrids have attracted extensive attention as an important catalyst in energy and environmental fields, due to their superior multifunctions and mechanical stability. This review aims to address the fabrication strategies, the identification of the enhancement mechanisms, and recent progress regarding the design and modification of MXenes/CNTs-based hybrids. A myriad of fabrication techniques have been systematically summarized, including mechanical mixing, spray drying, three-dimensional (3D) printing, self-assembly/in-situ growth, freeze drying, templating, hydrothermal methods, chemical vapor deposition (CVD), and rolling. Importantly, the identification of the enhancement mechanisms was thoroughly discussed from the two dimensions of theoretical simulations and in-situ analysis. Moreover, the recent advancements in profound applications of MXenes/CNTs-based hybrids have also been carefully revealed, including energy storage devices, sensors, water purification systems, and microwave absorption. We also underscore anticipated challenges related to their fabrication, structure, underlying mechanisms, modification approaches, and emergent applications. Consequently, this review offers insights into prospective directions and the future trajectory for these promising hybrids. It is expected that this review can inspire new ideas or provide new research methods for future studies.