Study On Preparation,Supercapacitive Performance And Glucose Sensing Property Of Ti₃C₂T_x/NiCo-LDH Nanomaterials

With the emphasis on energy utilization and health detection issues,the demand for cheap,high-performance energy storage materials and medical sensing materials has increased dramatically.Layered Double Hydroxide(LDH)is a layered clay material.Its unique large specific surface area and interlayer anion exchangeability make it suitable for energy storage,sensing and pollution adsorption.,Catalysis and drug carriers have many important application values.NiCo-LDH has the characteristics of abundant raw materials,low price,and large specific surface area.Moreover,both Niand Co elements have multiple oxidation states and high redox activity.Therefore,domestic and foreign researchers have studied their electrochemical energy storage and glucose sensing Some research was performed on performance.However,the poor conductivity of NiCo-LDH limits the improvement of its electrochemical performance.Ti₃C₂T_x is a typical MXene material,with a two-dimensional layered structure,high conductivity,excellent stability and good hydrophilicity.Combining the two materials and synthesizing their advantages is expected to obtain high-performance super-electricity and glucose sensing materials.In this thesis,Ti₃C₂T_x/NiCo-LDH nanocomposites were prepared by hydrothermal method.A variety of detection methods were used to characterize its morphology,structure and composition.Finally,the energy storage and glucose sensing performance of the material were systematically investigated.Moreover,the application experiment of asymmetric supercapacitors was also studied.The main findings are as follows:(1)The Ti₃C₂T_x nanosheet was combined with NiCo-LDH by hydrothermal method to prepare Ti₃C₂T_x/NiCo-LDH composite material.The effect of the amount of Ti₃C₂T_x added on the morphology of the composite material was studied.It was found that:through the morphological characterization,the NiCo-LDH nanosheets were aggregated and stacked in the composite material with 5mg Ti₃C₂T_x,while the composite material with 10mg Ti₃C₂T_x showed obvious Three-dimensional porous structure.When the content of Ti₃C₂T_x is increased to 20 mg or even 30 mg,the pore size of the NiCo-LDH nanosheet array gradually becomes too large to fully cover Ti₃C₂T_x.(2)The effect of the amount of Ti₃C₂T_x added on the performance of Ti₃C₂T_x/NiCo-LDH composite supercapacitor was studied.It was found that the composite material(T10/LDH)with 10 mg Ti₃C₂T_x had the most excellent electrochemical performance.When the current density is 2 A/g,the T10/LDH electrode exhibits the highest specific capacitance of 730 F/g;when the current density is 10 A/g,the electrode specific capacitance is 580 F/g,which is better than NiCo-LDH(340 F/g),T5/LDH(420 F/g),T20/LDH(480 F/g)and T30/LDH(312 F/g);when the current density rises to 20A/g,the T10-LDH electrode's The specific capacitance reduced to480F/g(capacitance retention rate is 65.9%)still surpasses the other four electrodes,which proves that the T10/LDH electrode has good rate characteristics.In addition,the electrode has a capacitance retention rate of 81%of the initial capacitance after 2000cycles at a current density of 4 A/g,so the electrode has good stability.The asymmetric supercapacitor constructed by T10/LDH electrode and activated carbon electrode showed an energy density of 40.22 Wh/kg at a power density of 800 W/kg.In addition,two ASCs connected in series can light green LEDs after charging,demonstrating practical application value.(3)The effect of Ti₃C₂T_x on glucose sensing performance of NiCo-LDH material was studied.It was found that the linear range of Ti₃C₂T_x/NiCo-LDH nanocomposites is0.002?4.096 m M,the detection limit is 0.53?M,and the current response time is 3s,while the linear range of pure NiCo-LDH is 0.002 m M?1.096 m M,the detection limit is0.969?M,The current response time is 7s,so the addition of highly conductive Ti₃C₂T_xbroadens the linear range of the detection electrode,reduces the response time of the detection electrode and obtains lower detection limits.(4)The selectivity,reproducibility and stability of Ti₃C₂T_x/NiCo-LDH electrode were studied,and it was found that the response current of composite materials to Na Cl,fructose and other interfering substances is much smaller than that to glucose.Therefore,the material has good selectivity to glucose.The relative standard deviation(RSD)of the response current of 7 electrodes prepared under the same conditions to 1 m M glucose was 3.59%,indicating that the electrode has excellent reproducibility.The current response of the same electrode to 1 m M glucose was 94.3%of the initial value after 7 days,and 92.5%of the original value after 15 days,showing good stability.In this thesis,Ti₃C₂T_x/NiCo-LDH nanocomposites were synthesized by a simple hydrothermal method and their applications in supercapacitor and non-enzymatic glucose sensors were studied.These results broaden the application field of NiCo-LDH-based composite materials,and have important reference value for preparing high-performance energy storage devices and fast and accurate non-enzymatic glucose sensor devices.