Fabrication of Ag/TiO2 nanoheterostructures with visible light photocatalytic function via a solvothermal approach

Abstract

In this work, Ag/TiO₂ nanoheterostructures with Ag nanocrystals well-grown on TiO₂-based nanofiber mats have been achieved by means of a novel and straighforward protocol combining an electrospinning technique and a solvothermal process. The experimental results indicated that the morphology and size of the secondary Ag nanostructures could be tailored by altering the experimental parameters, such as the reaction time and solvent as well as the reducing agent in the solvothermal treatment. The investigation of photocatalytic ability showed that the Ag/TiO₂ nanoheterostructures possess an excellent photocatalytic activity superior to the pure TiO₂ nanofiber for the degradation of Rhodamine B (RB) dye driven by visible light. The results indicated that Ag might be responsible for the visible light induced photocatalytic degradation by improving the photogenerated electrons and holes separation as well as charge migration, allowing both the electrons and holes to partake in the overall photocatalytic reaction. In addition, Ag has a good light absorption capability, extending the response of TiO₂ to visible light. Finally, the corresponding possible mechanism related to the photocatalytic performance of the Ag/TiO₂ nanoheterostructures was discussed in detail. Additionally, the separation and recovery process of the Ag/TiO₂ nanoheterostructures might be easily acheived by sedimentation without a decrease in the photocatalytic ability because of their particular one-dimensional nanostructured nature.