Synthesis, photoluminescence and photocatalytic characteristics of Ag–ZnO sandwich structures

The Ag–ZnO sandwich structure (columnar, cylinder and scallops-shaped) have been successfully synthesized. The X-ray diffraction results demonstrated characteristic peaks of hexagonal wurtzite ZnO and face-centered cubic Ag, which validate the architectured Ag–ZnO sandwich structure. The growth process of Ag–ZnO sandwich structures was explained by vapor-liquid-solid mechanism. Photoluminescence spectrum of Ag–ZnO sandwich structures showed visible emission intensity was 7 times higher than that in ultraviolet wavelengths, which can be ascribed to carriers injection effect of Ag core. The excellent photodegradation activity originates from the synergistic effects caused by three factors, including large surface area, unique ohmic contact of Ag–ZnO, and the electron transfer effect in the bandgap structure. This work provides an ideal alternative material for exploring the red light-emitting diode and photocatalysts devices.