Preparation and Chemosensory Properties of Nanocomposite Obtained by Hydrothermal Modification of Ti₂CT_x with Hierarchically Organized Co(CO₃)_0.5(OH)⋅0.11H₂O

The process of modification Ti₂CT_x MXene multilayer by hydrothermal synthesis of bulk hierarchically organized formations of Co(CO₃)_0.5(OH)⋅0.11H₂O has been studied. It is shown that under the chosen conditions the MXene is partially oxidized to form aggregates of titanium dioxide nanoparticles with a diameter of ~3–10 nm on its surface. The sensing properties of the obtained composite material at room temperature and relative humidity 65 ± 3% to a wide range of gaseous analytes (50 ppm CO, benzene, acetone, ethanol, 2500 ppm H₂, CH₄, 5% O₂, and 40 ppm NH₃, NO₂) have been investigated. Increased sensitivity has been found for the detection of 40 ppm NH₃ and NO₂: the responses have been found to be 91 and 63%, respectively. Some aspects of the detection mechanism are discussed. The results obtained show promising modification of multilayer MXene with semiconducting metal oxides and hierarchically formed bulk formations in order to improve its chemoresistive properties.