Interface Engineering of Steel-Wool-Shaped Cu–Co₃O₄ for Bisphenol A Degradation with Persulfate via the Tunable Mechanism

The efficient activation of the O-O band in persulfate (PDS) with high energy was important and could be achieved by the interface engineering of catalysts. It was discovered that the robust bisphenol A (BPA) degradation could be achieved in the presence of PDS via different mechanisms with steel-wool-shaped Cu-Co₃O₄ composites obtained via in-situ hydrolysis of cobalt and copper nitrate with zeolitic imidazolate framework-67 after calcination. The calcination temperature at 483 K resulted in abundant oxygen vacancies in Cu-Co₃O₄ with the amorphous structure, which displayed about a 25-fold higher degradation rate constant (<i>k</i> = 0.385 min^-1) than that (0.015 min^-1) of Co₃O₄ for BPA disposal with PDS, possibly via forming the surface-activated complex process. The higher temperature (583 K) treated Cu-Co₃O₄ could also lead to the fast BPA degradation with the <i>k</i> of 0.670 min^-1, which was more than 160-fold higher than the referenced Co₃O₄ and experienced the radical and nonradical processes, including the HO^•, SO₄^•-, O₂^•-, and ¹O₂ as reactive oxygen species. The above difference was possibly due to the amount of oxygen vacancy, the ratio of metal ions with different oxidation states, and the interaction of Cu-O-Co in the composite.