fig5

Figure 5. DFT calculation results illustrating the interfacial electronic structure regulation and PMS activation mechanism in the CuFeO₂–MX composite system. (A) Optimized geometric structure models of the CuFeO₂–MX and MX–CuFeO₂–MX systems; (B) Differential charge density distributions of CuFeO₂–MX and MX–CuFeO₂–MX, where the yellow and blue regions represent electron accumulation and electron depletion, respectively; (C and D) Planar-averaged electrostatic potential distributions along the surface normal direction and the corresponding work functions of CuFeO₂–MX and MX–CuFeO₂–MX; (E) Total d-band center positions of the two systems calculated from the PDOS; (F) Reaction free-energy pathway of PMS activation on the MX–CuFeO₂–MX interface. DFT: Density functional theory; PMS: peroxymonosulfate; CuFeO₂–MX: CuFeO₂–MXene; PDOS: projected density of states.