Platinum-Nanoparticle-Modified TiO2 Nanowires with Enhanced Photocatalytic Property

摘要

Highly crystalline Pt nanoparticles with an average diameter oF 5 nm were homogeneously modified on the surfaces of TiO2 nanowires (Pt-TiO2 NWs) by a simple hydrothermal and chemical reduction route. Photodegradation of methylene blue (MB) in the presence of Pt-TiO2 NWs indicates that the photocatalytic activity of TiOa NWs can be greatly enhanced by Pt nanoparticle modification. The physical chemistry process and photocatalytic mechanism for Pr-TiO2 NWs hybrids degrading MB were investigated and analyzed. The Pt attached on TiO2 nanowires induces formation of a Schottky barrier between TiO2 and Pt naonopanicles, leading to a fast transport of photogenerated electrons to Pt particles. Furthermore. Pt incoporation on TiO2 surface can accelerate the transfer of electrons to dissolved oxygen molecules. Besides enhancing the electron-hole separation and dharge transfer to dissolved oxygen. Pt may also serve as an effective catalyst in the oxidation of MB. However, a high Pt loading value does not mean a high photocatalytic activity. Higher content loaded Pt nanoparticles can absorb more incident photons which do not contribute-to the photocatalytic efficiency, The highest photocatalytic activity For the Pt-TiO2 nanohybrids on MB can be obtained at 1 at % Pt loading.