Strategies for Fabricating High‐Performance Electrochemical Energy‐Storage Devices by MXenes

Recent development review of Ti3C2Tx MXene-based microsupercapacitors: a multi-dimensional analysis spanning from underlying mechanisms to integrated applications

Microsupercapacitors, as innovative energy storage devices, have garnered significant attention in microelectronics and wearable applications. The urgent demand to enhance the charge storage capacity and operational efficiency of MSCs, coupled with challenges such as limited charge-active sites and low ion transport efficiency, has driven continuous optimization of their constituent materials and structural designs. The emerging two-dimensional MXenes, with their rich surface chemical functionalities, tunable interlayer spacing, and excellent compatibility with various nanomaterials, offer unprecedented opportunities for MSCs. However, current analyses of how MXenes enhance the performance of MSCs from the energy storage mechanism perspective, their multiple applications in MSCs, and the system-level integration of MSCs are incomplete, limiting the development of this field. Herein, this review presents a comprehensive overview of the latest advancements in the energy storage mechanisms and fabrication techniques of Ti3C2Tx-based MSCs, especially emphasizes their applications across various components of MSCs, and provides a detailed summary of integrated examples of MSC-powered systems. This work offers an in-depth analysis of the key role of Ti3C2Tx in enhancing the performance of MSCs, as well as outlines the challenges and prospects for its forthcoming research, with the potential to drive continued innovation in high-performance flexible energy storage devices.

A Review on Multifunctional Polymer-MXene Hybrid Materials for Electronic Applications

MXenes, a family of two-dimensional (2D) transition metal carbides, carbonitrides, and nitrides, have emerged as a promising class of nanomaterials for interdisciplinary applications due to their unique physiochemical properties. The large surface area, excellent electrical conductivity, superior mechanical properties, and abundant possible functional groups make this layered nanomaterial an ideal candidate for multifunctional hybrid materials for electronic applications. This review highlights recent progress in MXene-based hybrid materials, focusing on their electrical, dielectric, and electromagnetic interference (EMI) shielding properties, with an emphasis on the development of multifunctionality required for advanced electronic devices. The review explores the multifunctional nature of MXene-based polymer nanocomposites and hybrid materials, covering the coexistence of a diverse range of properties, including sensory capabilities, electromagnetic interference shielding, energy storage, and the Joule heating phenomenon. Finally, the future outlook and key challenges are summarized, offering insights to guide future research aimed at improving the performance and functionality of MXene-polymer nanocomposites.

MXenes as emerging adsorbents for removal of environmental pollutants

MXenes are a recently emerging class of two-dimensional nanomaterials that have gained considerable interest in the field of environmental protection. Owing to their high surface area, abundant terminal groups, and unique two-dimensional layered structures, MXenes have demonstrated high efficacy as adsorbents for various pollutants. Here we focused on the latest developments in the field of MXene-based adsorbents, including the structure and properties of MXenes, their synthesis and modification methods, and their adsorption performance and mechanisms for various pollutants. Among the pollutants that have been reported to be adsorbed by MXenes are radionuclides (U(VI), Sr(II), Cs(I), Eu(III), Ba(II), Th(IV), and Tc(VII)/Re(VII)), heavy metals (Hg(II), Cu(II), Cr(VI), and Pb(II)), dyes, per- and polyfluoroalkyl substances (PFAS), antibiotics (tetracycline, ciprofloxacin, and sulfonamides), antibiotic resistance genes (ARGs), and other contaminates. Moreover, future directions in MXene research are also suggested in this review.

MXene-Embedded Electrospun Polymeric Nanofibers for Biomedical Applications: Recent Advances

Recently MXenes has gained immense attention as a new and exciting class of two-dimensional material. Due to their unique layered microstructure, the presence of various functional groups at the surface, earth abundance, and attractive electrical, optical, and thermal properties, MXenes are considered promising candidates for various applications such as energy, environmental, and biomedical. The ease of dispersibility and metallic conductivity of MXene render them promising candidates for use as fillers in polymer nanocomposites. MXene-polymer nanocomposites simultaneously benefit from the attractive properties of MXenes and the flexibility and facile processability of polymers. However, the potentiality of MXene to modify the electrospun nanofibers has been less studied. Understanding the interactions between polymeric nanofibers and MXenes is important to widen their role in biomedical applications. This review explores diverse methods of MXene synthesis, discusses our current knowledge of the various biological characteristics of MXene, and the synthesis of MXene incorporated polymeric nanofibers and their utilization in biomedical applications. The information discussed in this review serves to guide the future development and application of MXene-polymer nanofibers in biomedical fields.

A Rising 2D Star: Novel MBenes with Excellent Performance in Energy Conversion and Storage

As a flourishing member of the two-dimensional (2D) nanomaterial family, MXenes have shown great potential in various research areas. In recent years, the continued growth of interest in MXene derivatives, 2D transition metal borides (MBenes), has contributed to the emergence of this 2D material as a latecomer. Due to the excellent electrical conductivity, mechanical properties and electrical properties, thus MBenes attract more researchers' interest. Extensive experimental and theoretical studies have shown that they have exciting energy conversion and electrochemical storage potential. However, a comprehensive and systematic review of MBenes applications has not been available so far. For this reason, we present a comprehensive summary of recent advances in MBenes research. We started by summarizing the latest fabrication routes and excellent properties of MBenes. The focus will then turn to their exciting potential for energy storage and conversion. Finally, a brief summary of the challenges and opportunities for MBenes in future practical applications is presented.

Thermal Properties of MXenes and Relevant Applications

The properties and applications of MXenes (a family of layered transition metal carbides, nitrides, and carbonitrides) have aroused enormous research interests for a decade since the successful synthesis of few-layer transition metal carbides in 2011. Though MXenes, as the building blocks, have already been applied in various fields (such as wearable electronics) owing to the distinctive optical, mechanical and electrical properties, their thermal stability and intrinsic thermal properties were less thoroughly investigated compared to other characteristics in early reports. The pioneering theoretical prediction of the thermoelectric nature of MXenes was performed in 2013 while the first experiment-based report concerning the degradation behavior of the 2D structure at elevated temperatures in a controlled atmosphere was published in 2015, followed by numerous discoveries regarding the thermal properties of MXenes. Herein, after a brief description of the synthesis, this Review summarized the latest insights into the thermal stability and thermophysical properties of MXenes, and further associated these unique properties with relevant applications by multiple examples. Finally, current hurdles and challenges in this field were provided along with some advices on potential research directions in the future.

Element-Doped Mxenes: Mechanism, Synthesis, and Applications

Heteroatom doping can endow MXenes with various new or improved electromagnetic, physicochemical, optical, and structural properties. This greatly extends the arsenal of MXenes materials and their potential for a spectrum of applications. This article comprehensively and critically discusses the syntheses, properties, and emerging applications of the growing family of heteroatom-doped MXenes materials. First, the doping strategies, synthesis methods, and theoretical simulations of high-performance MXenes materials are summarized. In order to achieve high-performance MXenes materials, the mechanism of atomic element doping from three aspects of lattice optimization, functional substitution, and interface modification is analyzed and summarized, aiming to provide clues for developing new and controllable synthetic routes. The mechanisms underlying their advantageous uses for energy storage, catalysis, sensors, environmental purification and biomedicine are highlighted. Finally, future opportunities and challenges for the study and application of multifunctional high-performance MXenes are presented. This work could open up new prospects for the development of high-performance MXenes.

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/carbon nanotube (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 summarized the recent advances in the application of MXene/CNT hybrids in energy storage devices, sensors, electrocatalysis, electromagnetic interference shielding, and water treatment, in which the function of individual components was clarified. In the end, the current research trend in this field were discussed and several technical issues were highlighted along with some suggestions on future research directions.