Ag-Modified ZnO Nanorod Array Fabricated on Polyester Fabric and Its Enhanced Visible-Light Photocatalytic Performance by a Built-in Electric Field and Plasmonic Effect

ZnO nanorod arrays (NRAs) were fabricated on polyester fabrics (PFs) by a two-step method and modified with Ag by magnetron sputtering. The photogenerated charge transport properties of the Ag/ZnO nanorod heterojunctions were studied by a self-made Kelvin probe system and a surface photovoltage (SPV) test system. The measured work functions (WFs) of the deposited Ag and ZnO nanorod are 4.67 and 5.56 eV, respectively. The SPV spectra indicate that the direction of the inner electric field is from the Ag layer to the inner of the ZnO nanorod. The enhancement of light absorption by the local surface plasma resonance (LSPR) effect of Ag/ZnO NRA was observed by Raman microspectroscopy and UV-vis diffuse reflectance spectroscopy. The photocatalytic activity of the Ag/ZnO NRA-functionalized PFs was evaluated by the photocatalytic degradation of Rhodamine B (RB) solution under visible light. The full photo-oxidation of RB and the outperforming ZnO NRA-coated PFs demonstrate that the enhanced photocatalytic performance of Ag/ZnO NRA-coated PFs results from the cooperation of the inner electric field of the Ag/ZnO nanorod heterojunction and Ag LSPR.