Persulfate activation of CuS@Ti3C2-based MXene with Bi-active centers toward Orange II removal under visible light

The Ti 3 C 2 -based MXene with unique lamellar nanostructure and high conductivity is expected to effectively improve photocatalytic ability of composites as a cocatalyst. Herein, two dimensional Ti 3 C 2 -based MXene nanosheets decorated with copper sulfide particles (CuS@MXene) were synthesized by hydrothermal treatment to boost catalytic persulfate (PS) activation under light, exhibiting remarkable reactivity and stability for the rapid removal of Orange II. The phase composition of CuS@MXene was detected by X-ray diffraction (XRD), the morphology of CuS@MXene was characterized by scanning electron microscope (SEM), and the results of X-ray photoelectron spectroscopy (XPS) proved the elemental composition and valence state of elements in the CuS@MXene. The dosage of PS and initial pH of solution were the main factors affecting the removal rate of Orange II, and the quenching experiment showed that 1 O 2 was the primary reactive species for the removal of Orange II in CuS@MXene -PS system. In addition, this study showed that CuS@MXene provided bi-active centers for PS activation, which was mainly attributed to the rapid charge transfer between dual electron-rich active centers of Cu and Ti. This system may be applicable to the degradation of other challenging organic pollutants .