CuCo2O4 supported on activated carbon as a novel heterogeneous catalyst with enhanced peroxymonosulfate activity for efficient removal of organic pollutants.

CuCo2O4 was synthesized via a relatively simple method, and innovatively supported onto the activated carbon (AC) by calcination to obtain a novel heterogeneous catalyst (AC-CuCo2O4). Brilliant red 3BF (3BF) was selected as the probe compound to investigate the catalytic activity of AC-CuCo2O4 in the presence of peroxymonosulfate (PMS). The results showed that 98% removal rate could be achieved and the reaction rate constant (0.476 min-1) was 5.2 times greater than that of CuCo2O4 alone (0.091min-1), suggesting that the introduction of AC could greatly enhance the catalytic activity of pure CuCo2O4. Typically, the 3BF removal was as high as 96% after five cycles, showing the good stability of catalyst reuse. Additionally, the effects of the initial pH, catalyst dosage, PMS concentration and reaction temperature on the 3BF removal were investigated, demonstrating that AC-CuCo2O4 effectively remove 3BF over a wide pH range (5.0-10.0) and possessed temperature-tolerant performance. To further explore the 3BF removal mechanism, electron paramagnetic resonance technology combining with trapping agents was employed to confirm the involvement of reactive oxygen species including SO4•-, •OH, O2•- and 1O2, which distinctly differed from the reported CuCo2O4 for PMS activation. These findings provided an addition promising strategy in environmental remediation.