ONE-DIMENSIONAL PLASMONIC NANO-PHOTOCATALYSTS: SYNTHESIS, CHARACTERIZATION AND PHOTOCATALYTIC ACTIVITY
This study describes a simple two-step approach to coat gold nanorods with a silica/titania shell. Gold nanorods with an aspect ratio of 2.5 (L = 48 {+-} 2 and d = 19 {+-} 1) are synthesized by a silver-seed mediated growth approach according to our previously reported procedure (Hunyadi Murph ACS Symposium Series, Volume 1064, Chapter 8, 2011, 127-163 and reference herein). Gold nanorods are grown on pre-formed gold nano-seeds in the presence of surfactant, cetyltrimethylammonium bromide (CTAB), and a small amount of silver ions. A bifunctional linker molecule which has a thiol group at one end and a silane group at the other is used to derivatize gold nanorods. The silane group is subsequently reacted with both sodium silicate and titanium isopropoxide to a silica/titania shell around the gold nanorods. By fine tuning the reaction conditions, the silica/titania shell thickness can be controlled from {approx}5 to {approx}40nm. The resulting nanomaterials are stable, amenable to scale up and can be isolated without core aggregation or decomposition. These new materials have been characterized by scanning electron microscopy, energy dispersive X-ray analysis, UV-Vis spectroscopy and dynamic light scattering analysis. Photocatalytic activity of Au-silica/titania nanomaterials under visible and UV illumination is measured via degradation of a model dye, methyl orange (MO) under visible and UV illumination. The results indicate a 3 fold improvement in the photocatalytic decomposition rate of MO under visible illumination vs. UV illumination.
- Research Organization:
- Savannah River Site (SRS), Aiken, SC (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- DE-AC09-08SR22470
- OSTI ID:
- 1022068
- Report Number(s):
- SRNL-STI-2011-00478; TRN: US1104123
- Resource Relation:
- Conference: SPIE Conference
- Country of Publication:
- United States
- Language:
- English
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