Synthesis and Chemoresistive Properties of Single-Layer MXene Ti2CTx

As part of the study, we have developed a method for obtaining a single-layer Ti2CTx MXene by the interaction of Ti2AlC with a mixture of hydrochloric acid and sodium fluoride followed by delamination using a tetramethylammonium hydroxide solution and ultrasonic exposure. The obtained stable aqueous dispersion of Ti2CTx has been applied by microplotter printing onto a specialized sensor chip, which has been dried at a temperature of 150 degrees C under reduced pressure. The coating has been studied using modern physicochemical methods of analysis. According to the data of X-ray spectral elemental microanalysis, the ratio n(Ti) : n(F + Cl) = 2 : (0.82-0.85), n(F) : n(Cl) approximate to 6 : 4; aluminum impurity does not exceed 1.5-2.0%. Data have been obtained on the local electrophysical properties of the Ti2CTx coating: on the value of the electron work function from the surface of the material, the distribution of charge carriers, and the capacitance gradient of the probe tip-sample microregion capacitor. For the first time, at an operating temperature of 30 degrees C, extremely high chemoresistive responses of the Ti2CTx receptor layer to the content of 1 and 5% oxygen in nitrogen have been determined, which amounted to 8.6 and >276, respectively.

Automated summary

In this study, a method for obtaining a single-layer Ti2CTx MXene material has been developed and applied onto a sensor chip. The properties of the coating have been analyzed using advanced physicochemical methods. The experiment results show that the Ti2CTx receptor layer exhibits extremely high chemoresistive responses to 1% and 5% oxygen content in nitrogen at 30 degrees C.