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.

The design and synthesis of organic polymers for photocatalytic hydrogen evolution have attracted recent attention. However, the corresponding work on the synthesis methods and optimal synthesis sites of organic polymers are not complete. This paper was to synthesize five organic polymer photocatalysts via a Suzuki cross-coupling polymerization reaction. The effect of linking position content on the photocatalytic H₂-evolution and photoelectrochemical performances of organic polymer semiconductors was investigated. The results show that the increase of 1,6-linkage pattern severely affects the photocatalytic hydrogen evolution effect. A 1,6-linked pyrene benzothiadiazole polymer (L16-PyBT) has a photocatalytic hydrogen evolution rate of 6.81 mmol/(h·g) under visible-light irradiation, which is greater than that of L2 (i.e., 2.80 mmol/(h·g) and L27-PyBT (i.e., 0.34 mmol/(h·g). The increased photocatalysis is since 1,6-linkage has a stronger π-π stacking, and better absorption/wettability. The evolution of this connection mode provides an important idea for the synthesis and design of organic polymers in the future.