MXene/Carbon Nanotube Hybrids: Synthesis, Structures, Properties and Applications

Since the successful preparation of few-layer transition metal carbides from three-dimensional MAX phases in 2011, MXenes (known as a family of layered transition metal carbides, nitrides and carbonitrides) have been intensively studied. Though MXenes have been adopted as active materials in many applications, issues including aggregation and restacking are likely to hamper their potential applications. In order to address these prevailing challenges, the concept of MXene/CNT hybrids was proposed initially in 2015, where CNTs were incorporated as the spacers and conductive additives. Ever since, MXene/CNT hybrids with different architectures have been synthesized by a number of methods and applied in numerous fields. Herein, after the discussion about general synthesis approaches, architectures and properties of the hybrids, this review summarizes the recent advances in the application of MXene/CNT hybrids in energy storage devices, sensors, electrocatalysis, EMI shielding and water treatment, in which the function of individual components is clarified. In the end, we conclude the current research trend in this field and highlight several technical issues along with some suggestions on future research directions.