Research On The Preparation And Application Of Two-dimensional MXene-based Materials

MXene is a general term for two-dimensional transition metal carbides,nitrides and carbonitrides,and usually has excellent electrical conductivity,flexibility and energy storage performance.Therefore,MXene has been widely used in super capacitors,batteries,photocatalysis and other fields.But in most reports,MXene is compounded with other materials in order to improve performance.This will cause the material characterization and mechanism analysis to become more complicated and difficult,and the synthesis process is complicated and the preparation cycle is long.On the basis of fully studying the characteristics of MXene materials,this topic adjusts the structure of the layer spacing,size and surface groups through simple,environmentally friendly and low-cost preparation processes?such as solvothermal,ultrasonic,magnetic stirring,etc.?to adjust MXene's electrical conductivity,magnetic and optical properties and other properties,so that simple MXene materials in the field of electrocatalytic nitrogen fixation,nano-enzyme catalysis,electromagnetic wave absorption and other fields play a greater role.Hydroxyl-rich Ti₃C₂T_x MXene quantum dots were prepared by reducing the size of MXene materials and controlling the types of surface groups for electrochemical nitrogen fixation at room temperature and pressure:using Ti₃C₂T_x MXene nanosheets as raw materials,through alkalization,intercalation and shearing,the prepared hydroxyl-rich Ti₃C₂Tx MXene quantum dots?Ti₃C₂OH QDs?showed excellent catalytic performance.The reduction in size allows the material to expose more edge Ti sites and increase its catalytic rate,while-OH groups on the surface of the material can increase its catalytic efficiency.The optimal NH₃ yield and Faraday efficiency of the Ti₃C₂OH QDs are 62.94?g h^-1 mg^-1_cat.and 13.30%,respectively.In addition,the catalyst has good selectivity and stability.Ti₃C₂T_x MXene-derived TiO₂/C-QDs derived from Ti₃C₂Tx MXene are used for the effective detection of glutathione in human serum by adjusting the interface characteristics and reducing the material size:single layer or few layers of Ti₃C₂T_x MXene nano by hydrothermal treatment The Ti atoms on the surface of the sheet are oxidized in situ to form TiO₂ with oxygen vacancies.The appearance of oxygen vacancies will be beneficial to the adsorption and activation of oxygen in the solution and increase its oxidase activity.After the size is reduced,it can be more fully contacted with the test object to improve the detection speed.It has been found that it can detect the concentration of GSH by colorimetry.And because of its good biocompatibility,specificity and high sensitivity,this detection method can be used to detect the concentration of GSH in complex biological samples?such as human serum?.By increasing the interlayer distance and the number of surface groups of the MXene material,it enhances its dielectric loss ability and reflection loss ability to improve its electromagnetic wave absorption performance:Nb₂CT_x MXene nanosheets increase the interlayer distance and the number of surface functional groups after solvent heat treatment.The analysis found that the material's electromagnetic wave absorption performance has been significantly improved after solvent heat treatment.This is because the increase in the interlayer distance increases the incidence of electromagnetic waves and the number of reflections,and the increase in surface groups enhances its dielectric loss capability.