Effect of Ti 3 AlC 2 MAX Phase on Structure and Properties of Resultant Ti 3 C 2 T x MXene

作者：Christopher E. Shuck, Meikang Han, Kathleen Maleski, Kanit Hantanasirisakul, Seon Joon Kim, Jung‐Hoon Choi, William E. B. Reil, Yury Gogotsi · 发表于：ACS Applied Nano Materials · 年份：2019 · DOI：10.1021/acsanm.9b00286 · 被引用次数：400 · 研究领域：MXene and MAX Phase Materials、2D Materials and Applications、Advanced Memory and Neural Computing

Ti 3 C 2 T x MXene is an attractive two-dimensional (2D) material for a wide variety of applications; however, measured properties vary widely from study to study. A potential factor to the property differences relates to variability in the MAX phase precursors. To illustrate this, Ti 3 AlC 2, the precursor for Ti 3 C 2 T x MXene, was synthesized using three carbon sources (graphite, carbon lampblack, and titanium carbide (TiC)) at 1650 °C for 2 h. Thermal analysis was utilized to examine the reaction mechanism, indicating that the three carbon sources experience different reaction pathways. The Ti 3 AlC 2 MAX powders were then converted into Ti 3 C 2 T x MXene and delaminated. The products revealed differences with respect to the lateral flake size, chemical composition, chemical stability in deionized water, and electrical conductivity. Graphite-produced Ti 3 C 2 T x showed the highest conductivity (∼4400 S/cm) and is the most stable (time constant of 10.1 days), while TiC-produced MXene has comparable conductivity (∼3480 S/cm), but the lowest colloidal stability (4.8 days), and carbon lampblack has the lowest conductivity (∼1020 S/cm) and low chemical stability (5.1 days). Furthermore, gas sensors were fabricated from all three MXenes to probe differences in their performance. The TiC-produced Ti 3 C 2 T x showed the highest response, followed by graphite-produced, and last Ti 3 C 2 T x produced from carbon lampblack. This illustrates that synthesis of the MAX precursor ma...