摘要
Activated carbon has been synthesized from the waste filter carbon in household water purifier. The original waste filter carbon (OFC) gives poor specific capacitance. However, the activated carbon SA-900-4 (OFC was heat treated at 900 degrees C to get SC-900, then SC-900 was activated by KOH with mass ratio of SC-900:KOH = 1:4 at 800 degrees C) shows great electrochemical performance. The SA-900-4 has a specific capacitance of 122.8 F g(-1) at current density of 1 A g(-1) in 1 M H2SO4 electrolyte. Furthermore, the specific capacitance of SA-900-4 is 93.8 F g(-1) at 10 A g(-1) and 78.1 F g(-1) at 20 A g(-1), nearly 76 and 63.6% of the value at 1 A g(-1), respectively, indicating good rate capacity of this activated carbon. In addition, the highest energy densities of 15.4 Wh kg(-1) in 1 M H2SO4 and 32.9 Wh kg(-1) in 1 M Na2SO4 were obtained respectively for the two-electrode supercapacitors based on SA-900-4. It is demonstrated that the waste filter carbon has the potential to be recycled as electrode material for electrochemical energy storage.