Materials, Methods & Technologies, Volume 7, 2013

Rezumat: In this work, we report a heterogeneous Ag/ZnO Photocatalysis absorption in the visible range can be improved by surface modification by adding noble metals such as Ag, Pd, and Au and their alloys. Our work demonstrates the application the synthesis of supported nanoparticle Photocatalyst catalysts for different applications such as water and anti-microbial treatment. Here, we report two step synthesis method of Ag/ZnO Nanoparticle Photocatalyst. The method is based on the synthesis of monodispersed ZnO nanoparticle through chemical reduction and microwave irradiation followed by the deposition of 1 wt. % Ag nanoparticles onto the surface of ZnO nanoparticles through deposition- precipitation method followed by microwave irradiation. The nanostructures of the prepared Ag/ZnO particles have been confirmed using UV-VIS absorbance, XRD, and SEM analysis. Ag/ZnO nanoparticles have been tested as a Photocatalyst for the degradation of Methylene Blue (MB) in water. The Photocatalyst is tested first for discoloration of MB in water under visible solar radiation and then using UV/Ag/ZnO system. Our results indicate that Ag/ZnO nanoparticles remove the color of Methylene Blue (MB) from water. Also, UV/Ag/ZnO system confirms the removal of MB from aqueous solutions containing 5 mg/L MB using small amount of Ag/ZnO Photocatalyst completely. Our kinetic study indicates that the Photocatalytic degradation of MB using UV/ZnO/Ag system follows pseudo-first order kinetics. The increase of Photocatalyst dose enhances both the rate and efficiency of MB degradation. We attributed the photocatalytic activity of the Ag/ZnO Photocatalyst to Plasmon surface effect of Ag nanoparticles and interaction of Ag with ZnO. Ag nanoparticles act as an electron sink, promoting interfacial charge transfer reducing charge recombination.