Peroxydisulfate activation using Fe, Co co-doped biochar and synergistic effects on tetracycline degradation

In this study, a low-cost and stable bimetallic biochar (Fe-Co/BC) was synthesized and used to activate peroxydisulfate (PDS) for tetracycline (TC) degradation. The optimized Fe-Co/BC-3 exhibited excellent catalytic activity with a kobs of 0.082 min−1, which was over 70, 25, 20 and 13 times those of PDS, pure BC, Fe/BC and Co/BC, respectively. The significantly enhanced catalytic performance can be attributed to the synergistic effects of iron and cobalt, where Co was inferred to be the dominant catalytic site for SO4•− generation, while Fe played a key role to the synergism with Co by acting as the primary adsorption site for the reaction substrates. The excellent anti-interferences of the Fe-Co/BC-3/PDS system in the environmental background further validated the superiority of the synergistic effects. This study is expected to improve the efficiency of the synthesis for bimetallic materials and elucidate the rational design for PDS activation.