The exciting combination of high electrical conductivity, high specific capacitance and colloidal stability of two-dimensional Ti3C2Tx MXene (referred to as MXene) has shown great potential in a wide range of applications including wearable electronics, energy storage, sensors, and electromagnetic interference shielding. To realize its full potential, recent literature has reported a variety of solution-based processing methodologies to develop MXenes into multifunctional architectures, such as fibres, films and aerogels. In response to these recent critical advances, this review provides a comprehensive analysis of the diverse solution-based processing methodologies currently being used for MXene-architecture fabrication. A critical evaluation of the processing challenges directly affecting macroscale material properties and ultimately, the performance of the resulting prototype devices is also provided. Opportunities arising from the observed and foreseen challenges regarding their use are discussed to provide avenues for new designs and realise practical use in high performance applications.
29 July 2021 in ACS Applied Materials & Interfaces
A two-step pre-intercalation strategy is developed, using ammonium citrate as an all-in-one intercalant, antioxidant and nitrogen source, for producing nitrogen-doped Ti3C2Tx MXene with improved electrochemical capacitance and high-rate performance.
X‐rays are a penetrating form of high‐energy electromagnetic radiation with wavelengths ranging from 10 pm to 10 nm. Similar to visible light, X‐rays provide a powerful tool to study the atoms and elemental information of objects. Different characterization methods based on X‐rays are established, such as X‐ray diffraction, small‐ and wide‐angle X‐ray scattering, and X‐ray‐based spectroscopies, to explore the structural and elemental information of varied materials including low‐dimensional nanomaterials. This review summarizes the recent progress of using X‐ray related characterization methods in MXenes, a new family of 2D nanomaterials. These methods provide key information on the nanomaterials, covering synthesis, elemental composition, and the assembly of MXene sheets and their composites. Additionally, new characterization methods are proposed as future research directions in the outlook section to enhance understanding of MXene surface and chemical properties. This review is expected to provide a guideline for characterization method selection and aid in precise interpretation of the experimental data in MXene research.
Titanium carbide (Ti3C2Tx) MXene has attracted significant attention due to its exceptional properties and versatile solution processibility. However, MXene dispersions are prone to various degradation processes, leading to the formation of byproducts that negatively affect its morphological, electrical, and mechanical properties. Through the years, several methods have been developed to mitigate MXene degradation; however, divergent viewpoints on the understanding of degradation mechanisms are prevalent, hindering the development of versatile strategies in producing environmentally stable MXene dispersions. This review provides a chronological analysis of the research efforts aimed at unraveling the underlying mechanisms of MXene degradation and highlights strategies for circumventing this process. This review discusses apparent inconsistencies in experimental findings and theoretical models. These discrepancies prompt further investigation for a clearer understanding of the degradation process in MXene. This narrative allows readers to follow the evolution of dominant theories and disputes and to ultimately stimulate further investigation, aiming for a better understanding of this process. It is anticipated that identifying the fundamental factors affecting the oxidation of MXene dispersions will enable their full‐scale processing into higher‐order structures and practical devices with greater longevity and long‐term performance.