Synthesis of Au@AgAuS core–shell hybrid nanorods and their photocatalytic application

Abstract

Hybrid nanostructures combining plasmonic metals and metal chalcogenide semiconductors are powerful materials for achieving high photocatalytic activity because of the synergistic properties of the two components. In the present study, we report a water-based synthesis strategy to fabricate [email protected] core–shell hybrid nanorods from Au nanorod seeds via sequential sophisticated synthetic methods involving seed-mediated growth, a galvanic replacement reaction, and a surface-selective sulfidation reaction. The morphological evolutions (from core–shell to yolk–shell and back to core–shell) and compositional conversions (from plasmonic bimetals to a plasmonic metal–rare-mixed-metal chalcogenide) during the consecutive reactions were systematically investigated. Because the unique composition, structure, and plasmonic characteristics of the [email protected] hybrid nanorods motivated us to use them as photocatalysts, we evaluated their photocatalytic activity via the photocatalytic oxidation of methylene blue under sunlight irradiation.