Plasma Enhanced Wet Chemical Surface Activation of TiO₂ for the Synthesis of High Performance Photocatalytic Au/TiO₂ Nanocomposites

Abstract

To enhance the effectiveness of TiO2 as a photocatalyst, it was believed that the drawbacks of the large bandgap and the rapid electron-hole recombination can be overcome by coupling TiO2 with plasmonic metal nanoparticles. The incorporation of the nanoparticles onto the TiO2 surface requires a suitable procedure to achieve the proper particle adhesion. In this work, we propose a simple, clean, and effective surface activation of TiO2 using plasma enhanced wet chemical surface treatment. Under only 5 min of plasma treatment in a 3% NH3/3% H2O2 solution, gold nanoparticles were found better adhered onto the TiO2 surface. Hence, the methylene blue degradation rate of the Au/TiO2 under sunlight treated was improved by a factor of 3.25 times in comparison to non-treated Au/TiO2 and by 13 times in comparison to the bare rutile TiO2.

Keywords

• plasma-liquid interaction
• sunlight degradation
• Au/TiO₂ nanocomposite
• surface treatment
• noble metal based photocatalyst