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Ti₃C₂T_xMXene membranes have attracted considerable interest due to their exceptional water transport properties, yet the role of cation intercalation on governing transport remains poorly understood. In this experimental and theoretical study, it shows how intercalation with K⁺, Na⁺, Li⁺, Ca²⁺, and Mg²⁺modulates both the nanochannel architecture and water flux of Ti₃C₂T_xmembranes. Unlike in graphene oxide analogs, cations with larger hydration diameters in Ti₃C₂T_xexpand the interlayer spacing, widening flow channels, enhancing slip length of these nanochannels, and boosting water flux from 31.45 to 61.86 L m⁻² h⁻¹. To overcome intrinsically poor adhesion of Ti₃C₂T_xto polymeric supports, this study incorporates a thin polyvinyl‐alcohol interlayer, which substantially enhances mechanical robustness and structural integrity. Together, these findings elucidate how cation hydration controls water transport and offer a flexible strategy for tailoring MXene membrane performance. 

Abstract MXenes exhibit remarkable properties, including high electrical conductivity, tunable surface chemistry, outstanding mechanical strength, and notable hydrophilicity. Recent advancements in bio‐functionalization have further enhanced these intrinsic characteristics, unlocking unprecedented opportunities for MXenes across a wide spectrum of applications in both biomedical and environmental domains. This review provides an in‐depth analysis of the synthesis strategies and functionalization techniques that improve MXenes' biocompatibility and expand their potential uses in cutting‐edge applications, including implantable and wearable devices, drug delivery systems, cancer therapies, tissue engineering, and advanced sensing technologies. Moreover, the review explores the utility of bio‐functionalized MXenes in areas such as corrosion protection, water purification, and food safety sensors, underscoring their versatility in addressing urgent global challenges. By conducting a critical evaluation of current research, this review not only highlights the immense potential of bio‐functionalized MXenes but also identifies pivotal gaps in the literature, offering clear pathways for future exploration and innovation in this rapidly evolving field. 

Abstract Biomolecule isolation is a crucial process in diverse biomedical and biochemical applications, including diagnostics, therapeutics, research, and manufacturing. Recently, MXenes, a novel class of two‐dimensional nanomaterials, have emerged as promising adsorbents for this purpose due to their unique physicochemical properties. These biocompatible and antibacterial nanomaterials feature a high aspect ratio, excellent conductivity, and versatile surface chemistry. This timely review explores the potential of MXenes for isolating a wide range of biomolecules, such as proteins, nucleic acids, and small molecules, while highlighting key future research trends and innovative applications poised to transform the field. This review provides an in‐depth discussion of various synthesis methods and functionalization techniques that enhance the specificity and efficiency of MXenes in biomolecule isolation. In addition, the mechanisms by which MXenes interact with biomolecules are elucidated, offering insights into their selective adsorption and customized separation capabilities. This review also addresses recent advancements, identifies existing challenges, and examines emerging trends that may drive the next wave of innovation in this rapidly evolving area. 

MXenes have demonstrated potential for various applications owing to their tunable surface chemistry and metallic conductivity. However, high temperatures can accelerate MXene film oxidation in air. Understanding the mechanisms of MXene oxidation at elevated temperatures, which is still limited, is critical in improving their thermal stability for high-temperature applications. Here, we demonstrate that Ti ${}_3$C ${}_2$T ${}_x$MXene monoflakes have exceptional thermal stability at temperatures up to 600 ${}^{°}$C in air, while multiflakes readily oxidize in air at 300 ${}^{°}$C. Density functional theory calculations indicate that confined water between Ti ${}_3$C ${}_2$T ${}_x$flakes has higher removal energy than surface water and can thus persist to higher temperatures, leading to oxidation. We demonstrate that the amount of confined water correlates with the degree of oxidation in stacked flakes. Confined water can be fully removed by vacuum annealing Ti ${}_3$C ${}_2$T ${}_x$films at 600 ${}^{°}$C, resulting in substantial stability improvement in multiflake films (can withstand 600 ${}^{°}$C in air). These findings provide fundamental insights into the kinetics of confined water and its role in Ti ${}_3$C ${}_2$T ${}_x$oxidation. This work enables the use of stable monoflake MXenes in high-temperature applications and provides guidelines for proper vacuum annealing of multiflake films to enhance their stability. 

Abstract Janus structures have unique properties due to their distinct functionalities on opposing faces, but have yet to be realized with flowing liquids. We demonstrate such Janus liquids with a customizable distribution of nanoparticles (NPs) throughout their structures by joining two aqueous streams of NP dispersions in an apolar liquid. Using this anisotropic integration platform, different magnetic, conductive, or non-responsive NPs can be spatially confined to opposite sides of the original interface using magnetic graphene oxide (mGO)/GO, Ti₃C₂T_x/GO, or GO suspensions. The resultant Janus liquids can be used as templates for versatile, responsive, and mechanically robust aerogels suitable for piezoresistive sensing, human motion monitoring, and electromagnetic interference (EMI) shielding with a tuned absorption mechanism. The EMI shields outperform their current counterparts in terms of wave absorption, i.e., SE_T ≈ 51 dB, SE_R ≈ 0.4 dB, and A = 0.91, due to their high porosity ranging from micro- to macro-scales along with non-interfering magnetic and conductive networks imparted by the Janus architecture. 

Gas separation membranes incorporating two-dimensional (2D) materials have received considerable attention in recent years, as these membranes have shown outstanding physical, structural, and thermal properties and high permeability- selectivity. The reduced thickness and diversity of the gas transport mechanisms through in-plane pores (intrinsic defects), in-plane slitlike pores, or plane-to-plane interlayer galleries provide the membranes with a significant sieving ability for energy-efficient gas separation. The discovery of 2D transition metal carbides/nitrides materials, MXenes, has provided new opportunities in the gas separation membrane area because of their hydrophilicity, rich chemistry, high flexibility, and mechanical strength. This Review puts into perspective recent advances in 2D-material-based gas separation membranes. It discusses research opportunities mainly in MXene-based gas membranes, highlights modification approaches for tuning the in-plane and plane-to-plane nanoslits, explains governing mechanisms of transport through these membranes, and compares their advantages and disadvantages with those of other 2D materials. It also discusses current challenges and provides prospects in this area.