Performance and mechanism of natural chalcopyrite for photocatalytic activation of peroxymonosulfate towards tetracycline degradation

The work provides an efficient method of Tetracycline (TC) treatment by using natural chalcopyrite (NCP) as the photocatalytic activation of peroxymonosulfate (PMS) in aqueous. The results demonstrate that compared to simply NCP or PMS processes, the efficiency of TC removal (100% within 40 min) in the NCP/PMS/Light system was significantly enhanced. The kinetic constants for the NCP, PMS and NCP/PMS/Light systems were 0.0031, 0.010 and 0.1133 min(-1) respectively. Finally, the mechanics of TC degradation were researched. The active species (SO4 center dot(-) , center dot OH, center dot O-2(-) and O-1(2)) was the main reason for the degradation of TC. Cycling of metal sites (Cu2+/ Cu+, Fe3+/Fe2+) on NCP improved the activation of PMS to produce more free radicals (SO4 center dot(-), center dot OH). As electron acceptor, PMS stimulated the generation of center dot O-2(-) radical, while enhanced the separation of photogenerated electrons and holes and fulfilled the synergistic effect of photocatalysis and PMS.