Research On Modification And Electric Adsorption Performance Of Activated Carbon Fiber

The activated carbon fiber?ACF?felt was used as raw material,it was pretreated by water washing and pickling,the treatment effects of HCl was studied under the condition of boiling,shaking and ultrasound;ACF were loaded of copper and titanium compounds to chemically modify by impregnation-burning method.Adsorption properties of ACF were by ash and iodine value;the physical and chemical properties of the samples were characterized by specific surface area and pore size,SEM,TG,FTIR,XRD and XPS;the changes of electrochemical performance of the samples were analyzed by CV curve.Experimental results of pretreatment shows that effect of HCl ultrasonic treatment to ash is the best,but the surface structure of the sample is severely damaged;the iodine value,specific surface area and pore volume of the samples with other methods are increased except for ultrasonic treatment,adsorption performance is enhanced,and the specific capacitance is increased as well.Treatment effects of various pretreatment methods by comprehensive comparison are as follows:HCl oscillation>HCl boiling>water washing>HCl ultrasound,when the concentration of HCl was 4%,the oscillation time is 40min,the processing temperature is 50?,the treatment effect of HCl oscillation is the best,the average pore size is reduced from 2.06nm to 2.01nm,the specific surface area and total pore volume are increased respectively by 32.73%and 34.28%,specific capacitance is increased by 27.7%.ACF surface oxygen groups are increased after acid pickling treatment,which is conducive to the adsorption of inorganic ions.The treated sample treated by hydrochloric acid oscillation was loaded respectively to modify by CuO and TiO₂.The result shows that the surface oxygen groups are increased and Ti-O and Cu-O bonds are present after loading the the metal oxides,specific surface area and total entrance of the modified ACF are reduced,while specific capacitance is increased.When concentration of Cu?NO₃?₂ is 2%,the processing temperature is 250?,the loading effect is the best,specific surface area and total entrance of CuO-ACF are decreased respectively by 31.94%and 33.95%,specific capacitance is increased by17.95%under the condition of the optimal processing,CuO existed in monoclinic system,relative content of Cu in CuO-ACF is 13.7%;the loading effect of TiO₂ is greatly affected by calcination temperature,the optimum processing temperature of TiO₂-ACF is determined to be 450?,at the temperature,specific surface area and total entrance of TiO₂-ACF are decreased by 17.98%and 21.53%,TiO₂ exists in the tetragonal system,relative content of titanium in TiO₂-ACF is 6.3%.In summary,the adsorption properties and electrochemical properties of ACF were improved significantly through pretreating by hydrochloric acid and loading to modify by metal oxides.