Micropatterning MXene/TiO₂ Nanocomposite Ink for Gas Sensing

This work describes the preparation, characterization and micropatterning of MXene (Ti 3 C 2 /TiO 2 ) nanocomposite inks. The MXene nanopowder was oxidized to Ti 3 C 2 /TiO 2 nanocomposite powder by stirring in air for 3 hours using air aging method. The Ti 3 C 2 /TiO 2 nanocomposite powder was then dispersed into Dimethyl Sulfoxide (DMSO) solvent, and the Ti 3 C 2 /TiO 2 ink was prepared by using 1% mass fraction of Polyvinylpyrrolidone (PVP) solution as dispersant. The two-dimensional layered nanostructure of MXene and the characteristic peaks of TiO 2 were observed by Raman and XRD results. SEM and TEM results show the layered structure of MXene nanoparticles as well as TiO 2 nanoparticles with a diameter of about 2 nm on a single layer of MXene. FTIR results confirms that Ti-O bonds and Ti-C bonds indicating that part of Ti 3 C 2 was oxidized to TiO 2 . The results of Brunauer Emmett Teller (BET) test on Ti 3 C 2 /TiO 2 nanocomposite ink show that the specific surface area of the ink is 10.7194 m²/g and the maximum adsorption of N 2 is 32.039cm 3 /g. Thermogravimetric analysis (TGA) indicate that Ti 3 C 2 /TiO 2 exhibited excellent thermal stability, with a mass loss of only 15% at 800°C. In order to achieve the optimal printing effect, plasma surface treatment was carried out on the gold-plated silicon wafers, Polyethylene terephthalate (PET), and glass substrates, which decreases the contact angle of the ink on these substrates. The printing of Ti 3 C 2 /TiO 2 nanocomposite ink on the substrate using the atomized printing technique with a mask plate enables printing of straight lines with a line width of 5µm. Film thickness can be controlled by adjusting the distance between the printhead and the substrate, as well as the pressure of the atomized printing jet.