Stabilizing Ti₃C₂T_x in a Water Medium under Multiple Environmental Conditions by Scavenging Oxidative Free Radicals

Abstract

MXene nanosheets have been worthy contenders for various applications owing to their unique physicochemical properties but can be easily oxidized to lose their functional properties, especially in a water medium with unclear oxidation mechanism. Here, we investigate the effect of main free radicals in water on the oxidation of Ti 3 C 2 T x and screen out the corresponding effective scavengers. It is found that •OH is more detrimental to Ti 3 C 2 T x in water, and agents such as NaHCO 3 stabilizing Ti 3 C 2 T x by scavenging •OH have been proved to be effective at 50 °C and under visible light irradiation, extending the storage life of Ti 3 C 2 T x colloids up to 140 days at 5 °C. As a proof of concept, the NaHCO 3 -stablized Ti 3 C 2 T x is superior to the unprotected counterpart for supercapacitors and photocatalytic applications. It is expected that this study provides important insights into enhancing the oxidation resistance of Ti 3 C 2 T x in water and facilitates the application of Ti 3 C 2 T x -based materials under multiple environmental conditions.

Mixed‐Sized Graphene Oxides Induce Highly Densified MXene‐Based Films with High Conductivity and Exceptional Stability

“…This difference in water contact angles indicates that MX-GO(l/s) possessed a more compact and denser structure compared to MXene, which could account for its enhanced stability. [49][50] Harnessing the high stability, good conductivity, and remarkable flexibility of the MX-GO(l/s) film, we designed a radio frequency identification (RFID) tag antenna based on this film. The RFID antenna operated at a frequency range of 800-1000 MHz, with the corresponding skin depth in the nanometer range, which was significantly lower than the 3.18 μm thickness of MX-GO(l/s) to ensure the flow of surface current.…”

“…This difference in water contact angles indicates that MX‐GO(l/s) possessed a more compact and denser structure compared to MXene, which could account for its enhanced stability. [ 49–50 ]…”

Halogenated Ti3C2 MXenes Prepared by Microwave Molten Salt for Hg0 Photo‐Oxidation

“…[24] Studies have shown that the surface functional groups of MXenes greatly influence the energy band structure of MXenes. [25][26][27] However, the preparation of MXenes by liquid etching inevitably introduces fluorine and oxygen-containing functional groups, leading to uncontrollability of the type and content of functional groups and thus incapability of regulating the energy band structure, [28,29] and limitation of its photocatalytic application. As a traditional material synthesis method, Lewis salts with acidity in the molten state can selectively react with Al in Ti 3 AlC 2 to achieve green and safe preparation of Ti 3 C 2 MXene.…”

MXenes Are Still Hot

“…However, their large-scale application is challenged by the harsh processing steps needed as well as the poor chemical stability of the exfoliated phases. Publishing in Chemistry of Materials , researchers report on various strategies to address the challenges of etching, processing, and stabilizing Mxenes. − Not limiting MXenes to ordered transition metals, researchers have expanded the design space of MXene to include high-entropy phases. , A high throughput approach was used to search for interesting topological phases among the MXene family, and machine learning protocols were developed by theoreticians to broaden the compositional, structural, and performance space of MXenes . Porous composites of MXenes as well as conformal layer-by-layer assembly of MXenes for optoelectronics and energy storage were also developed.…”

“…By observing the degradation rate of Ti 3 C 2 T x in water in the presence of different radical scavengers, Wang et al . singled out OH radicals as the reactive oxygen radical responsible for the degradation of Ti 3 C 2 T x . Exfoliated V 2 CT x monolayers are susceptible to degradation in water and upon exposure to air.…”