Investigation of MXenes Oxidation Process during SPS Method Annealing

Abstract

This paper discusses the effects of the environment and temperature of the Ti3C2 (MXene) oxidation process. The MXene powders were annealed at temperatures of 1000, 1200, 1400, 1600, and 1800 °C in argon and vacuum using a Spark Plasma Sintering (SPS) furnace. The purpose of the applied annealing method was to determine the influence of a high heating rate on the MXene degradation scheme. Additionally, to determine the thermal stability of MXene during the sintering of SiC matrix composites, SiC–C–B–Ti3C2 powder mixtures were also annealed. The process parameters were as follows: Temperatures of 1400 and 1600 °C, and pressure of 30 MPa in a vacuum. Observations of the microstructure showed that, due to annealing of the SiC–C–B–Ti3C2 powder mixtures, porous particles are formed consisting of TiC, Ti3C2sym, and amorphous carbon. The formation of porous particles is a transitional stage in the formation of disordered carbon structures.

Modelling and Characterisation of Residual Stress of SiC-Ti3C2Tx MXene Composites Sintered via Spark Plasma Sintering Method

“…In this study, the influence of the MXene phase addition and the carbon structures’ formation during sintering on the presence of stresses in composites based on silicon carbide was analysed. MXene phases, as shown in previous studies [ 37 ], decompose during the sintering process to form highly defective carbon structures that play the role of a reinforcing phase. Due to the anisotropy of the thermal properties of graphite structures, the presence of internal stresses in the produced composites should be expected.…”

Thermal Properties of MXenes and Relevant Applications

“…[48] It has been reported that a small amount of oxygen adsorbed on the surface of Ti 3 C 2 T x sheets may oxidize the material at high temperatures (above 1200 °C) and completely damage the layered structure as the temperature increases further (up to 1800 °C), as shown in Figure 2(e)-(g). [49] In addition to Ti 3 C 2 T x , the decomposition behavior of other MXene species in vacuum, including Zr 3 C 2 T x and ordered double transition metal carbides (such as Cr 2 TiC 2 T x ), have been explored with details shown in Table 2. Apart from vacuum annealing, annealing in inert gaseous atmospheres (such as argon, helium and nitrogen) is considered as an alternative approach to investigate the thermal decomposition of MXenes, as shown in Table 2.…”

“…[49] Reproduced with permission from ref. [49] Copyright 2021 MDPI. stable at a high temperature level (~500 °C) while various surface terminations are detached in sequence, as shown in Table 3.…”

“…Nitrogen doping is achieved by forming NbÀ N bonds (nitrogen content: 4.5 at %) ChemPhysChem to the recrystallization and the subsequent removal of Ti atoms at high temperatures (above 1500 °C). [49,70] In addition to the complete disruption of the 2D structure, the modification of the surface terminations can be achieved by a solid-state chemical reaction at relatively low temperature levels (below 200 °C), as shown in Table 3. For example, Zang et al proposed a thermal-sulfurization strategy to perform sulfur-doping by substituting the functional groups (such as À OH and À F) of Ti 3 C 2 T x MXenes with sulfur, in which a mixture of sulfur powder and a Ti 3 C 2 T x -based composite was heated at 400 °C in argon for 2 hours.…”

“…Copyright 2018 Springer Nature. SEM images showing the morphological change of Ti 3 C 2 T x after annealing at (e) 1200 °C and (f) 1400 °C and (g) 1800 °C in vacuum [49]. Reproduced with permission from ref [49].…”