fig1

Figure 1. Morphological evolution and elemental analysis following electrode modification. (A) Step-by-step preparation scheme for the CuS-WA/CF composite electrode. (B and C) Low- and high-magnification SEM images of the as-received carbon felt (pristine CF). (D and E) SEM images of CuS-WA/CF, where the carbon fibers are conformally covered by a dense CuS layer. (F and G) EDS elemental mapping of Cu and S, demonstrating homogeneous distribution of both elements throughout the modified electrode.