Facile construction of Z-scheme AgCl/Ag-doped-ZIF-8 heterojunction with narrow band gaps for efficient visible-light photocatalysis

It is of great importance to fabricate photocatalyst with high photocatalytic activity, and the formation of Z-scheme heterojunction photocatalyst has been proved to be an effective way to restrain the recombination of photo-induced carriers. In this work, Z-scheme AgCl/Ag-doped-ZIF-8 heterojunction is synthesized via a two-step process involving appropriate amount of cationic Ag ion doping into the imidazole ring of ZIF-8 framework and the precipitation of AgCl onto this Ag-doped-ZIF-8. The successful doping of ZIF-8 which decreases the band gap energy, enhances the light harvesting. Besides, the separation efficiency of photo-induced carriers is further improved due to the formation of Z-scheme AgCl/Ag-doped-ZIF-8 heterojunction, which is confirmed by photoelectrochemical experiments. As a result, the as-prepared AgCl/Ag-doped-ZIF-8 photocatalyst possesses excellent photocatalytic activity under visible light illumination. This work will provide a novel perspective for the design and construction of Z-scheme heterojunction for highly efficient photocatalysis.