Long-Term Stability Studies and Applications of Ti3C2Tx MXene

Abstract

The novel 2D materials, MXenes, have many remarkable properties, but their stability against oxidation is a major bottleneck in their applications. In this study, we have investigated the stability of Ti3C2Tx MXene for up to 365 days under different conditions, e.g., in liquid form in different solvents, in dried form when coated at polyethylene terephthalate (PET) substrate, and during the application of Ti3C2Tx MXene in polymer-dispersed liquid crystal- (PDLC-) based smart windows as conducting electrodes. In liquid form, the MXenes were dispersed in different solvents including an antioxidant in DI water and other organic solvents, and the corresponding color change was analyzed. To estimate the stability in dried form, the MXenes were coated on PET substrates and their relative sheet resistance change, i.e., R − R 0 / R 0 , where R 0 is the initial resistance, was investigated under different conditions including MXene passivated with polymers and coated films stored under different environments. In the case of the MXene application-based stability study, the stability was investigated by using the MXenes as conducting electrodes in a switchable smart window application. The switchable behavior was observed by applying voltage (0-50 V) after different durations of up to 365 days. The MXene used in smart windows was preserved for a long time without additional treatment to MXene.

Monitoring Ti3C2Tx MXene Degradation Pathways Using Raman Spectroscopy

“…The observed spectral differences between the freshly formed films and those stored in oxygen may be attributed to the partial oxidation of MXene. Previous studies have shown that the extent of oxidation depends on the oxygen content during storage ,, and temperature …”

Shielding 2D MXenes against oxidative degradation: recent advances, factors and preventive measures

“…In basic media, the presence of OH À ions accelerates the oxidation of MXenes, and at higher MXene dispersion concentrations, the oxidation rate decreases due to steric shielding effects among the MXene flakes. 70,117…”

“…Fresh Ti 3 C 2 T x dispersions undergo a gradual color shift to a translucent cloudy appearance as oxidation progresses. 79,117 The rate of this change is notably influenced by both pH and reaction temperature. 77 Under fixed conditions of 20 °C, an increase in pH slows the rate of change, indicating that acidic conditions accelerate the oxidation process.…”