MXenes, a family of two-dimensional transition metal carbides, nitrides, and carbonitrides, have emerged as promising materials for supercapacitor applications due to their unique properties, including high electrical conductivity, large surface area, and excellent electrochemical performance. Their graphene-like structure and the transition metal layer confer excellent conductive and energy storage properties. Therefore, they can be used as electrode materials for capacitors and to promote research progress in areas such as solid-state batteries. This review summarizes recent advancements in MXene-based supercapacitors, focusing on synthesis methods, structural properties, and electrochemical performance enhancements achieved through various strategies. Challenges and future prospects of MXene-based supercapacitors are also discussed, providing insights for researchers and engineers in the field of energy storage

Tribocatalysis is receiving more and more attention for its great potential in environmental remediation. In this study, a special tribocatalysis was explored as a powder-free catalytic technology for the degradation of organic dyes. Polytetrafluoroethylene (PTFE) and titanium (Ti) disks were first assembled as magnetic rotary disks and then driven to rotate through magnetic stirring in dye solutions in beakers with PTFE, Ti, and Al₂O₃ disks coated on bottoms separately. PTFE and Ti generated dynamic friction with the disks on the beaker bottoms in the course of magnetic stirring, from which some interesting dye degradations resulted. Among those dynamic frictions generated, 40 mg/L rhodamine b (RhB), 30 mg/L methyl orange (MO), and 20 mg/L methylene blue (MB) were effectively degraded by the one between PTFE and PTFE, the one between Ti and Ti, and the one between PTFE and Ti, respectively. Hydroxyl radicals and superoxide radicals were detected for two frictions, one between PTFE and PTFE and the other between Ti and Ti. It is proposed that Ti in friction increases the pressure in blocked areas through deformation and then catalyzes reactions under high pressure. Mechano-radicals are formed by PTFE through deformation, and are responsible for dye degradation. This work demonstrates a powder-free tribocatalysis for organic pollutant degradation and suggests an especially eco-friendly catalytic technology to wastewater treatment.