Simple fabrication of the Ag-Ag_2O-TiO_2 photocatalyst thin films on polyester fabrics by magnetron sputtering and its photocatalytic activity

摘要

The polyester fabrics were modified with Ag-Ag2O-TiO2 coating. The TiO2 layer was prepared by DC magnetron sputtering and oxidation in air: a method which avoids the problem of Ti target poisoning in reactive sputtering. The Ag2O layer was deposited by DC reactive sputtering. As a contrast, the TiO2 layer of Ag-Ag2O-TiO2 coating was also prepared using radio frequency (RF) reactive sputtering in Ar/O-2 gas mixture. The surface photovoltage (SPV) spectrum and the measured work functions of samples indicate that a built-in electric field was formed at the interface between Ag2O layer and TiO2 layer. The photocatalytic efficiency was analyzed through monitoring the degradation of Rhodamine B (RB) under UV illumination. Compared to the polyester merely coated with TiO2, the polyester fabrics coated with Ag-Ag2O-TiO2 showed the superior performance of photocatalysis, indicating the Ag2O-TiO2 heterojunction contributes to photocatalytic degradation of RB. Results also show that the TiO2 layer in Ag-Ag2O-TiO2 coating prepared by DC magnetron sputtering and then natural oxidation had comparable photocatalytic activities with that prepared by RF reactive sputtering.