Fast and spontaneous reduction of gold ions over oxygen-vacancy-rich TiO2: A novel strategy to design defect-based composite photocatalyst

Authors:   Xiaoyang Pan, Yi-Jun Xu

Abstract:
A novel strategy has been developed for spontaneous reduction of gold ions on the TiO₂ with oxygen vacancies (TiO₂-OV) to obtain defect-based composite photocatalyst, during which neither additional reducing agents nor surfactants are required. The as-formed metallic gold nanoparticles are partially embedded into the surface of TiO₂ resulting from the binding with OV on the TiO₂ surface. Such an intimate interfacial contact between gold nanoparticles and TiO₂ can contribute to improving the separation and transport of charge carriers photogenerated from Au-TiO₂-OV hybrids under visible light irradiation as well as stabilizing gold nanoparticles on TiO₂. It is revealed that the electron transfer from OV states of TiO₂-OV to gold ions is responsible for the spontaneous formation of metallic gold nanoparticles. The results show that Au-TiO₂-OV shows enhanced visible light photoactivity toward Rhodamine B (RhB) degradation compared to the original TiO₂ and TiO₂-OV. The wavelength dependent photoactivity analysis further clarifies that the surface plasmon resonance (SPR) due to the excitation of gold nanoparticles under visible light irradiation is the driving force for the enhanced visible light photoactivity. It is hoped that our current work would provide a simple, fast strategy to synthesize defect-based composite photocatalysts for target applications.

Keywords:
Simple and fast strategy
Spontaneous reduction
Gold nanoparticles
Oxygen vacancy
Defect-based composite photocatalyst

Published in: Applied catalysis A: General  (Volume 459, Pages 1-130, 24 May 2013)

Publisher: Elsevier

ISSN Information: 0926-860X

Fast and spontaneous reduction of gold ions over oxygen-vacancy-rich TiO2: A novel strategy to design defect-based composite photocatalyst

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