Synergy between copper and cobalt on 3D Co/CuO complex promotes peroxymonosulfate activation

Activation of peroxymonosulfate (PMS) to degrade refractory antibiotics is an essential branch of advanced oxidation processes (AOPs). We reported in this study that the (1   1   1) and (0   0   2) crystal planes of CuO with the (3   1   1) crystal plane of Cu 0.72 Co 2.28 O 4 formed surface heterojunctions, which are used as interfaces for PMS adsorption to explore the performance of different heterojunctions. The formation of Cu 0.72 Co 2.28 O 4 /CuO heterojunction makes up for the CuO (0   0   2) surface’s shortcomings and improves the adsorption and activation of PMS by the CuO (0   0   2) surface. The heterojunction significantly grows the length of the PMS’ O-O bond compared to the single-crystal surface, which leads to lower energy required for PMS’ O-O bond breaking and further verified the increased covalent character. Based on the quality influencing factors values, the influence of four factors on sulfamethoxazole (SMX) deterioration fits as follows: HCO 3 – has the largest relative relevance among the factors, followed by H 2 PO 4 - , NO 3 – , and Cl - . The Box-Behnken methodology fitted the optimum efficiency with the initial concentration of Cl - , NO 3 – , H 2 PO 4 - , and HCO 3 – were 8.0, 10.0, 12.5, and 7.5 mM, respectively. The SMX’s atoms (N, and O) have higher electrophilic attack sites, indicating these atoms are electrophilic attack sites.