Synthesis And Capacity Properties Of Fe₃O₄/FL-Ti₃C₂T_x Composites

As a new kind of quasi-two-dimensional materials,Ti3C2 Tx has great advantage in the application of supercapacitor’s electrode,since it owns large theoretical specific surface area and good conductivity.However,the re-stack of Ti3C2 Tx leads to the dramatic decrease of surface area as well as the capacitance performance.To solve this problem,this paper has carried on the following research:Firstly,using three different methods—ultrasonic,dimethyl sulfoxide（DMSO）assisted ultrasonic and sulfonated aryl diazonium salt（SADS）surface modified—to transform the multi-layer Ti3C2 Tx into few layer Ti₃C₂T_x（FL-Ti₃C₂T_x）.By means of XRD,XRS and SEM,this thesis found that FL-Ti3C2 Tx prepared by DMSO method and SADS method were transparent to electronic beam and had large interlayer spacing,large size,and good dispersibility in water.Secondly,in order to further expand the interlayer spacing of FL-Ti3C2 Tx,Fe3O4 nanoparticle were added into the SADS method synthesized FL-Ti₃C₂T_x（SA-（FLTi₃C₂T_x））by coprecipitation.XRD,ICP-OES,SEM,EDS,and electrochemical analysis were applied in investigating the effects of the concentration of iron salt on the phase,morphology and capacitance performance of the product—Fe3O4/SA-（FLTi₃C₂T_x）composite.The results showed that,with the increase of iron salt concentration,the content and size of Fe3O4 nanoparticles in the product increased,as well as the degree of agglomeration.At the same time,the impedance and specific capacitance of product rised in the first stage and then decrease,but the tendency of rate performance was opposite.After cycling at 1A/g for 100 times,the specific capacitance were 10F/g（C（Fe2+）=0.003mol/L）,30F/g（C（Fe2+）=0.009mol/L）,and 8F/g（C（Fe2+）=0.027mol/L）,showing a more than 90% retention of capacitance for all.Finally,DMSO method synthesized FL-Ti₃C₂T_x（D-（FL-Ti₃C₂T_x））was used as loading-body of Fe3O4,with same synthesis and characterization method of Fe3O4/SA-（FL-Ti₃C₂T_x）.The results showed that,when the iron salt concentration increased,the content of Fe3O4 in the product was increased,but the particle size did not change.At the same time,the impedance and rate performance of product falled in the first stage and then rised,but the tendency of specific capacitance was opposite.After cycling at 1A/g for 1000 times,the specific capacitance were 100F/g（C（Fe2+）=0.003mol/L）,136F/g（C（Fe2+）=0.009mol/L）,and 112F/g（C（Fe2+）=0.027mol/L）,showing a capacitance retention rate of 111.1%,119.3% and 127.3%,respectively.