Preparation Of Fl-Ti₃C₂ Nanomaterials And Their Electrochemical Sensing Properties

Two-dimensional transition metal carbon/nitride?MXene?is a novel two-dimensional nanomaterials that has developed rapidly in recent years.They has excellent hydrophilicity,good electrical conductivity,large specific surface area and conductivity,etc..Two-dimensional MXene nanomaterials can be prepared by etching the MAX phase,which has become a hot spot in the electrocatalytic field,electrochemical sensors and supercapacitors.The multi-layered two-dimensional MXene nanomaterials are layered to obtain a few-layer MXene,which has a larger specific area and superior conductivity.Few-layer MXene used as an electrode materials in electrochemical sensing applications can not only preferably improve the contact area of the electrode for the substrate and the electron transfer rate on the electrode,but also increase the enzyme load and help to achieve direct electrochemistry between the enzyme and the electrode.Moreover,there are few reports on the application of few-layer MXene nanomaterials and their composite nanomaterials in the field of electrochemical sensing.In this paper,Few-layer Ti₃C₂?FL-Ti₃C₂?and FL-Ti₃C₂/PILs-MWNTs nanomaterials were successfully prepared,and their electrochemical sensing properties were studied.This thesis has provides new ideas for the development of new high-efficiency electrochemical sensors based on MXene materials.The main contents of this thesis are as follows:1.FL-Ti₃C₂ materials were successfully prepared after ultrasonic treatment of multilayer Ti₃C₂?ML-Ti₃C₂?with dimethyl sulfoxide?DMSO?intercalation.The electrochemical behaviors of the FL-Ti3C2 modified glassy carbon electrode?FL-Ti₃C₂/GCE?were investigated by cyclic voltammetry.The electrochemical detection performance of the modified electrode for catechol?CC?was studied by differential pulse voltammetry.The constructed FL-Ti3C2 electrochemical sensor has good electrochemical catalytic performance for CC oxidation.Compared with the bare electrode and the ML-Ti₃C₂ modified electrode,the CC oxidation potential of FL-Ti3C2/GCE is significantly reduced,and the oxidation current is dramatically increased.In addition,the experimental pH value of the electrolyte was optimized and the concentration of CC was detected by DPV.The results showed that the constructed FL-Ti3C2/GCE electrochemical sensor had a good linear relationship between the current response signal and the CC concentration range of 0.05?5000?mol/L.The correlation coefficient of the sensor is 0.9985 In addition,the constructed FL-Ti3C2/GCE electrochemical sensor also exhibited fairly strong anti-interference preformance and higher sensitivity,which could efficiently and sensitively detect CC.2.FL-Ti3C2/PILs-MWNTs nanocomposites were prepared using?-?interaction and electrostatic interaction.First of all,the nanocomposites?PILs-MWNTs?with good water dispersibility and distinct positive charge were prepared by modifying multi-walled carbon nanotubes?MWNTs?with polymeric ionic liquids?PILs?.Whereafter,the FL-Ti3C2 and PILs-MWNTs were compounded into FL-Ti₃C₂/PILs-MWNTs nanocomposites with positive charges by using the anion exchangeability of PILs.The ChOx/FL-Ti3C2/PILs-MWNTs modified electrode was constructed by assembling ChOx onto the surface of the FL-Ti3C2/PILs-MWNTs modified electrode through electrostatic interaction.The electrochemical behaviors of ChOx/FL-Ti3C2/PILs-MWNTs were characterized by CV.At the same time,the mechanism and performance of the as-prepared modified electrodes for detecting cholesterol were also studied.The results showed that the constructed ChOx/FL-Ti3C2/PILs-MWNTs showed excellent catalytic performance on cholesterol.The linear range of the sensor is0.05?35.0?mol/L,the correlation coefficient is0.9989 and the detection limit is 0.062?mol/L?S/N=3?.In addition,the constructed ChOx/FL-Ti3C2/PILs-MWNTs electrochemical sensor exhibited preferable stability and stronger anti-interference performance.The FL-Ti3C2/PILs-MWNTs nanocomposites as electrode materials effectively promoteed the electron transport between the immobilized enzyme and the MXene-based modified electrode,and provided a good platform for the development of electrochemical biosensors.