Precise control of ultramicropore structure of activated carbon fiber for the application of Cu(II) adsorption/electro-adsorption

Abstract To enhance the Cu(II) electro-adsorptivity of activated carbon fiber felt (ACFF), the ultramicropore volume at 0.56 nm is precisely enhanced by the process of sonication-assisted hydrochloric acid reactivation. The surface elemental composition of ACFF-H5 changes slightly and the chemical structure contains more carboxyl groups after the reactivation process. By the precise control of ultramicropore volume at 0.56 nm, Cu(II) adsorptivity of ACFF is increased by 267% in the process of 50 mg/L Cu(II) static adsorption. For the Cu(II) electro-adsorption process, the Cu(II) electro-adsorptivity of ACFF cathode are 49.94 mg/g and 85.16 mg/g for 50 mg/L and 130 mg/L Cu(II) solution respectively. By the low-temperature pickling regeneration process, this cathode can basically achieve 100% recovery of Cu(II) electro-adsorptivity in five cycles. Summarization By using ACFF with precise control of ultramicropore at 0.56 nm as a soft cathode, the Cu(II) electro-adsorptivity reaches 85.16 mg/g for 130 mg/L Cu(II) solution.