Paper NS+EN+MG+SS+TF-WeA3
Fabrication and SERS Activity of Metal-loaded TiO₂ Nanometer ScaleParticles

Wednesday, October 21, 2015, 3:00 pm, Room 212B

Our current research focuses on the fabrication and study of metallic loaded titanium dioxide (TiO₂) nanoparticles supported by highly oriented pyrolitic graphite (HOPG). Highly dispersed TiO₂ particles are formed via physical vapor deposition (PVD) under high vacuum settings with an average pseudo-diameter of 11.6 ± 2.65 nm. Metallic loading is completed by an ex-situ photo-deposition method by exposure to precursor metal salt solutions under TiO₂ bandgap UV irradiation. We have attempted to fabricate Pt-, Ag-, Au-, and Pt-Au-TiO₂ particles and observed photocatalytic enhancement with the inclusion of Pt nanoparticles deposited onto TiO₂ surfaces. We believe this enhancement is a result of Pt nanoparticles harboring free excited electrons and preventing electron-hole recombination. We have developed a technique to increase the density of TiO₂ particles by creating site defects on the surface of HOPG through plasma mild oxygen plasma exposure. Highly dispersed TiO₂ nanoparticle distributions allow an increase of metal nanoparticle formation on TiO₂ for surface and intrinsic property observations. Ag nanoparticles have been fabricated in order to observe Surface Enhanced Raman Spectroscopy (SERS) Ag nanoparticles were observed to be an average pseudo-diameter of 2.6 ± 1.4 nm. A probe molecule was used to determine Raman intensity enhancement factor (EF) and we believe that the EF can be affected by the spacing and size of Ag-TiO₂ nanoparticles. We will present our studies of bi-metallic loading of TiO₂.

This work is supported by the U.S. Department of Energy, Office of Basic Energy Sciences through grant

number: DE-FG02-96ER45576