Regulating the Co 3d center of Co₃O₄ by Co₃O₄/g-C₃N₄ to enhance electronic activity for sulfamethizole effectively degaradtion by permonosulfate activation

The Permonosulfate (PMS) activation via Co based catalysts have been recognized as the most effective PMS activation method. However, regulating the Co-3d band center of Co based catalysts to enhance PMS activation is still a challenge. Since g-C₃N₄ is often a good carrier for transition metals and their oxides, in this work, the Co₃O₄/g-C₃N₄ was developed by a simple way to modulate the Co-3d band center of Co₃O₄ and was used to sulfamethizole (STZ) degradation. Also, some characterizations demonstrated the Co₃O₄/g-C₃N₄ has been successfully prepared such as Transmission electron microscope (TEM), X-ray Diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It also showed an effective removal efficiency for STZ by PMS activation (k₁ = 0.77 min⁻¹). The reactive oxygen species (ROS) quenching experiments verified the main ROS are ¹O₂ and SO₄^•−. The DFT results indicated that the Co-3d of Co₃O₄ band center (from −1.78 eV to −1.41 eV) was successfully modulated, further improving the electronic utilization efficiency and electronic activity, thus effective PMS activation was obtained. This work not only provided a potential way to antibiotics removal in water, but also offered a mechanism analysis of PMS activation by Co-based catalysts in depth.