Fig. 2From: Facile Fabrication of Bi2WO6/Ag2S Heterostructure with Enhanced Visible-Light-Driven Photocatalytic Performances a The overall XPS spectrum of the as-prepared Bi2WO6/Ag2S heterostructures. XPS spectra of b Bi 4f, c W 4f, d O 1 s, e S 2 s, and f Ag 3dBack to article page