Gas-Sensing Properties of the Ti0.2V1.8CTx/V2O5 Nanocomposite

Abstract

A method was developed for producing a nanocomposite containing a Ti_0.2V_1.8CT_x MXene core and surface layers of titanium-doped vanadium oxide by relatively low temperature partial oxidation of multilayer MXene, a two-dimensional vanadium titanium carbide. It was shown that, during the oxidation of the initial Ti_0.2V_1.8CT_x in an air atmosphere at a temperature of 250°C, the microstructure of accordion-like aggregates is preserved with a slight increase in the porosity of their constituent layers and an increase in their thickness due to the formation of V₂O₅. The MXene structure was detected to be preserved with a decrease in the interplanar distance from 10.3 Å (initial Ti_0.2V_1.8CT_x powder) to 7.3 Å. Raman spectroscopy confirmed the formation of vanadium oxide. Kelvin probe force microscopy determined that, in the formation of Ti_0.2V_1.8CT_x/V₂O₅ nanocomposite, the work function decreases from 4.88 eV (Ti_0.2V_1.8CT_x) to 4.68 eV. A comprehensive analysis was made of the chemosensory properties of Ti_0.2V_1.8CT_x/V₂O₅ layers deposited by microplotter printing to a number of gaseous analytes (H₂, CO, NH₃, NO₂, C₆H₆, C₃H₆O, CH₄, C₂H₅OH, and O₂). At elevated detection temperatures (125–200°C), high sensitivity to oxygen (10% O₂) and NO₂ (100 ppm) was detected; throughout the entire temperature range (25–200°C), there were noticeable responses to humidity (50% RH). If the temperature detection was room temperature, good sensitivity to acetone, ethanol, and ammonia was observed.