Preparation of a nanoporous Cu-Ag solid solution with enhanced sono-Fenton-like catalytic activity

Uniform 3D bi-continuous nanoporous Cu-Ag solid solution (NPCS) and nanoporous copper (NPC) were successfully synthesized by dealloying Cu₇₀Y₂₈Ag₂ and Cu₇₂Y₂₈ metallic glasses, respectively, which was confirmed by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The SEM and TEM images show that the ligament size of NPCS (d _SEM = 65 nm, d _TEM = 45 nm) is much smaller than that of NPC (d _SEM = 402 nm, d _TEM = 370 nm), which reveals that the ligaments of NPC can be significantly refined by the substitution of 2 at% Ag for Cu in the amorphous precursor. The obtained NPCS exhibits much larger specific surface area and higher total pore volume (S _BET = 8.34 m² g^-1, V _p = 0.093 cm³ g^-1) compared to NPC (S _BET = 1.77 m² g^-1, V _p = 0.050 cm³ g^-1). Furthermore, the catalytic activities of the samples were evaluated by decomposing methyl orange (MO) dye under the irradiation of ultrasound. The results show that NPCS with an extreme fine microstructure displayed superior sono-Fenton-like catalytic activity compared to NPC and commercial copper foil.