1) Ti3C2Tx samples were obtained in the form of a delaminated suspension with different surface groups (Tx) due to the use of different leaching components. The resulting MXene films were analyzed using various physicochemical methods. It is shown that a 2D structure of the material was obtained for all synthesized samples, which indicates the complete leaching process with the selected leaching agents. The structure, morphology and structure of the obtained MXene samples were analyzed using XRF, SEM and optical microscopy.
2) It has been shown that the largest values ​​of the electrochemical window of electrolyte stability are – 2.6 V for NaClO4 (10 M) and – 2.5 V for LiCl (14 M), the maximum conductivity value is observed at a concentration of 6 M for NaClO4. The cathodic stability of the optimized electrolyte of 10 M NaClO4¬ and 14 M LiCl was shown to be approximately 200 mV lower when using the MXene active electrode due to its negligible catalytic effect in the reduction of hydrogen from H2O. The use of a saturated electrolyte based on NaCH3COOH leads to a decrease in the anodic zone of the electrochemical stability window due to the alkalization of the solution caused by the hydrolysis of NaCH3COOH.
3) It has been shown that the NaTi2(PO4)3 sample synthesized from NaAc compared to the synthesis from NaHCO3 has fewer impurity inclusions, which has a positive effect in electrochemical tests. Grinding the synthesized NaTi2(PO4)3 allowed to significantly reduce the particle size to 500 nm, the milled NaTi2(PO4)3 will be easier to integrate with MXene. Based on the results of cyclovoltammetry for NaTi2(PO4)3 samples, the capacity (80 mAh/g) and the position of de/intercalation peaks were determined.
4) The possibility of controlled oxidation of MXene using atmospheric oxygen (without the action of additional oxidizing agents) with the formation of titanium oxide has been demonstrated. Analysis of the results of studies using XRF, electron microscopy and Raman spectroscopy shows the presence of TiO2 in the form of anatase. The increased electrochemical activity of oxidized MXene compared to the starting material was shown due to the presence of the formed TiO2, which has Red/Ox activity. Oxidation of Ti3C2Tx by air oxygen is limited by the stage of diffusion of oxygen in solution to the surface of Ti3C2Tx. The speed characteristics of the charge/discharge process for a hybrid electrode based on MXene/TiO2, determined by the CV method, are higher than the values ​​​​for pure MXene, due to the increase in the interlayer space between individual MXene petals “pillaring effect” due to the formed TiO2 - faster access of the electrolyte. The percentage of TiO2 formed was determined by the electrochemical method by analyzing CV curves in LiCl and NaClO4 solutions. When oxidized with oxygen for 6 days, w(TiO2) ≈ 6%. The higher stability of the MXene/TiO2 hybrid electrode compared to pure TiO2 during long-term cycling is due to the MXene shell.
5) A hybrid electrode based on MXene/NaTi2(PO4)3 was manufactured using vacuum filtration. The mechanical strength of the resulting electrode depends on the percentage of NaTi2(PO4)3.