Stability Of MXene Research Articles

Recent Advancement in Emerging MXene-Based Photocatalytic Membrane for Revolutionizing Wastewater Treatment.

MXene-based photocatalytic membranes provide significant benefits for wastewater treatment by effectively combining membrane separation and photocatalytic degradation processes. MXene represents a pioneering 2D photocatalyst with a variable elemental composition, substantial surface area, abundant surface terminations, and exceptional photoelectric performance, offering significant advantages in producing high-performance photocatalytic membranes. In this review, an in-depth overview of the latest scientific progress in MXene-based photocatalytic membranes is provided. Initially, a brief introduction to the structure and photocatalytic capabilities of MXene is provided, highlighting their pivotal role in promoting the photocatalytic process. Subsequently, in pursuit of the optimal MXene-based photocatalytic membrane, critical factors such as the morphology, hydrophilicity, and stability of MXenes are meticulously taken into account. Various preparation strategies for MXene-based photocatalytic membranes, including blending, vacuum filtration, and dip coating, are also discussed. Furthermore, the application and mechanism of MXene-based photocatalytic membranes in micropollutant removal, oil-water separation, and antibacterial are examined. Lastly, the challenges in the development and practical application of MXene-based photocatalytic membranes, as well as their future research direction are delineated.

Enhanced Tribological Behaviour of Hybrid MoS2@Ti3C2 MXene as an Effective Anti-Friction Additive in Gasoline Engine Oil

Hybrid molybdenum disulfide (MoS2)-MXene (Ti3C2) was added as an additive in SAE 5W-40-based engine oil in an attempt to reduce interfacial friction between contact surfaces. It was found that the coefficient of friction (COF) and wear scar diameter (WSD) were reduced by 13.9% and 23.8%, respectively, with the addition of 0.05 wt.% MoS2-Ti3C2 compared to base engine oil due to the interlaminar shear susceptibility of MXene. However, we postulate that the high surface energy and presence of -OH, -O and -F functional groups on the surfaces limited the dispersibility and stability of MXene in base oil, while high activity of MoS2 nanoparticles due to large surface area and vigorous Brownian motion prompted fast settling of nanoparticles due to gravitational force. As such, in the present study, hybrid MoS2-Ti3C2 were amine-functionalized to attain stability in SAE 5W-40-based engine oil. Experimental findings indicate that amine-functionalized 0.05 wt.% MoS2-Ti3C2 exhibited higher COF and WSD, i.e., 12.8% and 12.3%, respectively, compared to base oil added with 0.05 wt.% unfunctionalized MoS2-Ti3C2. Similarly, Noack oil volatility was reduced by 24.6% compared to base oil, indicating reduced oil consumption rate, maximal fuel efficiency and enhanced engine performance for a longer duration.

A Review on MXene Synthesis, Stability, and Photocatalytic Applications.

Photocatalytic water splitting, CO2 reduction, and pollutant degradation have emerged as promising strategies to remedy the existing environmental and energy crises. However, grafting of expensive and less abundant noble-metal cocatalysts on photocatalyst materials is a mandatory practice to achieve enhanced photocatalytic performance owing to the ability of the cocatalysts to extract electrons efficiently from the photocatalyst and enable rapid/enhanced catalytic reaction. Hence, developing highly efficient, inexpensive, and noble-metal-free cocatalysts composed of earth-abundant elements is considered as a noteworthy step toward considering photocatalysis as a more economical strategy. Recently, MXenes (two-dimensional (2D) transition-metal carbides, nitrides, and carbonitrides) have shown huge potential as alternatives for noble-metal cocatalysts. MXenes have several excellent properties, including atomically thin 2D morphology, metallic electrical conductivity, hydrophilic surface, and high specific surface area. In addition, they exhibit Gibbs free energy of intermediate H atom adsorption as close to zero and less than that of a commercial Pt-based cocatalyst, a Fermi level position above the H2 generation potential, and an excellent ability to capture and activate CO2 molecules. Therefore, there is a growing interest in MXene-based photocatalyst materials for various photocatalytic events. In this review, we focus on the recent advances in the synthesis of MXenes with 2D and 0D morphologies, the stability of MXenes, and MXene-based photocatalysts for H2 evolution, CO2 reduction, and pollutant degradation. The existing challenges and the possible future directions to enhance the photocatalytic performance of MXene-based photocatalysts are also discussed.

Safety Assessment of 2D MXenes: In Vitro and In Vivo.

MXenes, representing a new class of two-dimensional nanomaterial, have attracted intense interest in a variety of fields as supercapacitors, catalysts, and sensors, and in biomedicine. The assessment of the safety of MXenes and related materials in biological systems is thus an issue that requires significant attention. In this review, the toxic effects of MXenes and their derivatives are summarized through the discussion of current research into their behaviors in mammalian cells, animals and plants. Numerous studies have shown that MXenes have generally low cytotoxicity and good biocompatibility. However, a few studies have indicated that MXenes are toxic to stem cells and embryos. These in vitro and in vivo toxic effects are strongly associated with the dose of material, the cell type, the mode of exposure, and the specific type of MXene. In addition, surface modifications alter the toxic effects of MXenes. The stability of MXenes must be considered during toxicity evaluation, as degradation can lead to potentially toxic byproducts. Although research concerning the toxicity of MXenes is limited, this review provides an overview of the current understanding of interactions of MXenes with biological systems and suggests future research directions.

Largely enhanced adsorption performance and stability of MXene through in-situ depositing polypyrrole nanoparticles

Due to the high presence of active functional groups, two-dimensional transition metal carbide/nitride materials that are usually named MXene have been thought as an efficient adsorbent for the removal of organic contaminants from wastewater. However, the poor stability of MXene originated from the high oxidization performance greatly restricts their application. In this work, few-layered MXene was firstly prepared and then the in-situ polymerization of polypyrrole (PPy) was induced in the MXene solution to prepare the MXene/PPy composite particles. The microstructure, adsorption behaviors toward methylene blue (MB) and the stability during the storage process were systematically investigated. The results show that introducing PPy nanoparticles promotes the further exfoliation of MXene. Consequently, the adsorption ability of the MXene/PPy composite particles is significantly enhanced, and the maximum adsorption capacity reaches 553.57 mg/g. The MXene/PPy composite particles also show high adsorption selectivity and it can exclusively remove MB from the solution mixing both cationic and anionic dyes simultaneously. The stability of the MXene is greatly enhanced and nearly no oxidization is observed for the MXene/PPy composite particles. This study offers an additional way to fabricate the MXene-based adsorbents with high stability, and the composite particles exhibit promising applications in effluent water remediation.

The oxidation and thermal stability of two-dimensional transition metal carbides and/or carbonitrides (MXenes) and the improvement based on their surface state

This work provides a comprehensive review focusing on the current research on the stability of MXenes and the methods to improve their stability.

MXene core-shell nanostructures with enhanced conductivity and stability

MXene, a novel two-dimensional material, can be used in a broad range of photoelectricity applications, such as electrooptic modulators, photodetectors and ironic batteries, and the conductivity and stability of MXene are both critical in these applications. However, The enhanced properties can be achieved via MXene modification, such as inserted irons into the interlayer of MXene, or formed complex materials by taking advantage of the active group on the surface of MXene. In this work, a core-shell nanostructure composed of Ti3C2 (MXene) and gold nanoparticles was obtained with a simple and controllable method, and the increase in conductivity and stability were both investigated. The optical measurement results suggested that the photoelectric interaction between the gold nanoparticles and Ti3C2 materials was fully utilized when assembled together in a core-shell nanostructure. Additionally, the electric measurement results showed that the resistance of the Ti3C2 material was distinctly reduced after the formation of the [email protected] core-shell nanostructure, with the maximum 20% decrease in resistance being achieved when the core-shell nanostructures were around 107 nm with gold shell of 7 nm, excited by a voltage of 2 V. In addition, compared with the pure Ti3C2 materials, the [email protected] core-shell nanostructures showed good long-term stability due to the antioxidation effect of the gold shell nanostructure. Therefore, this study paves the way toward the use of MXene-based materials in optoelectrical applications.

Graphene‐like nanocarbides and nanonitrides of d metals (MXenes): synthesis, properties and simulation

Very recently (2011, Advanced Materials , 23, 4248), an elegant exfoliation approach was proposed to prepare a new family of two-dimensional (2D)-like transition metal carbides and nitrides from layered MAX phases. This discovery has provided the next stage in the design of new graphene-like inorganic materials with intriguing functionalities and applications. This overview is intended as an introduction to this newest family of graphene-like quasi-2D nanocarbides and nanonitrides of d metals, which are known today also as MXenes. Here the authors discuss the available results achieved for MXenes (2011-2012), when a group of various MXenes (2D-Ta 4 C 3 , Ti 3 (C 0.5 N 0.5 ) 2 , TiNbC and some others) have been successfully synthesised, a set of their properties (conductivity, mechanical behaviour etc.) were measured and systematical theoretical studies of structural, electronic properties, chemical bonding and the stability of MXenes were initiated. Besides, possible applications of MXenes as promising materials for Li ion batteries, sensors or 2D electronics etc. are noted.