The Influence of Plasmonic Au Nanoparticle Integration on the Optical Bandgap of Anatase TiO2 Nanoparticles

Abstract

This work reports an investigation into the influence of the surface plasmon resonance (SPR) phenomenon of plasmonic Au nanoparticles on the optical bandgap of anatase titanium dioxide (TiO2) nanoparticles. In the study, the effect of particle integration on the optical bandgap of TiO2 nanoparticles was studied in two types of binary Au-TiO2 heterostructured materials, namely Janus Au-TiO2 nanostructures and core-shell Au@TiO2, and their optical absorption spectra were compared to the pristine anatase TiO2 nanoparticles. The anatase TiO2 nanoparticles was prepared using the sol-gel method. Well-dispersed Au nanoparticles with particle size diameter in the range of 19-33 nm were successfully synthesized using the seed-mediated method and exhibited unique light absorption due to SPR at 544 nm. Based on the results, the integration of Au nanoparticles was found to be responsible for the alteration of both light absorption behavior and the optical bandgap of TiO2. Spectroscopic analyses revealed that the presence of the SPR phenomenon was able to widen the light absorption range of TiO2 to the visible spectrum. In addition, the optical bandgap of the heterostructures was found to be slightly lower than the corresponding pristine anatase TiO2 nanoparticles.

Keywords

• Au nanoparticles
• Bandgap
• Kubelka-Munk
• Plasmonic
• TiO2 nanoparticles