Fig. 2: Macroscopic mechanism of Ag⁺ reduction on MoO_x.

a Optical photographs of FTO loaded with amorphous MoO_x before and after Ag⁺ adsorption. b SEM image revealing strip structure Ag particles. c XRD pattern showing the characteristic peaks of metallic Ag (the diffraction peaks marked with “*” originate from the FTO substrate). d High-resolution XPS spectra of the Ag 3d orbital. High-resolution XPS spectra of e Mo 3d and f O 1s orbitals for MoO_x before and after Ag⁺ uptake. g Macroscopic schematics of Ag⁺ capture. Mo(V) on MoO_x acts as an electron donor to reduce most of Ag⁺, and a small amount of Ag⁺ is trapped by complexation with MoO_x. Source data are provided as a Source Data file.