Insights into ibuprofen degradation in boron-doped CuO/PMS systems: Role of Cu, kinetics, mechanisms and degradation pathways

Recently, copper-based catalysts have become increasingly popular for peroxymonosulfate (PMS) activation due to its non-toxicity and effectiveness. In this study, we doped crystalline boron into CuO by coprecipitation and obtained a novel C-boron doped CuO catalyst (B-CuO). Characterization of materials revealed that the obtained B-CuO maintained a similar nanobelt structure to CuO. Meanwhile, BET surface area decreased from 13.32 to 12.03 m 2 /g and average pore diameter increased from 12.90 to 30.00 nm. The total pore volume also rose from 0.043 to 0.09 cm 3 /g. Compared to the CuO/PMS system, the B-CuO/PMS system showed higher ibuprofen (IBP) removal rate (92.9 % vs. 92.0 %) and k obs (0.130 min −1 vs. 0.063 min −1 ) with increased TOC removal (11.6 % vs. 8.4 %) in 30 min at 0.6 mM PMS, 0.096 g/L B-CuO, and 20 μM IBP, pH 7.5, T  = 25 °C. Based on quenching tests, EPR, and LC-MS results, a possible mechanism of IBP degradation dominated by ≡Cu(III) and OH with contribution ratio of 88.45 % and 11.55 % was proposed. Hydroxyl addition, demethylation, and decarboxylation were main IBP degradation pathways. In summary, doping of C-boron into CuO substantially enhanced PMS activation for IBP degradation. However, addressing the mineralization of pollutants remained a challenge.