Silver nanoparticles decorated grassy ZnO coating for photocatalytic activity enhancement

The ZnO/Ag composite photocatalysts were prepared via the deposition of Ag on the surface of the grassy ZnO by a simple immersion reduction method. The dosage of Ag in the composites was adjusted by the concentration of Ag ions, immersion time and the content of the reducing agent. The grassy ZnO substrate presented a hexagonal wurtzite structure and a uniform dispersion. The band gap of the ZnO/Ag composites was decreased than that of grassy ZnO due to the surface plasma resonance (SPR) effect caused by Ag modification. The photocurrent response of the composites with proper amount of Ag loading was greatly improved by the SPR effect of Ag and subsequently enhanced light absorption, which resulted in the separation of electron-hole pairs in the near surface region of the neighboring semiconductor. The ZnO/Ag composites had excellent photocatalytic efficiency in decolorization of RhB under UV irradiation.