Fabrication of Cu2O/Ag composite nanoframes as surface-enhanced Raman scattering substrates in a successive one-pot procedure

Semiconductor/metal composite nanomaterials have been used as surface-enhanced Raman scattering (SERS) active substrates and have attracted increasing attention due to their widespread applications in both optical and material fields. Here, we report a facile strategy to prepare highly sensitive SERS substrates with excellent reproducibility and stability based on uniform and well-controlled Ag nanoparticle (NP) decorated Cu2O nanoframes. Our strategy is a unique one-pot procedure. Simply, hollow Cu2O/Ag composite nanoframes (Cu2O/Ag CNFs) with tunable silver content have been successfully designed and constructed by reduction of Ag+ with sodium citrate in a 14 day old Cu2O-containing mother solution, and then a second component (Ag) was directly deposited onto primary nanomaterials (Cu2O nanoframes). There is an optimum amount of Ag NPs. When 0.40 mM AgNO3 is used, the prepared Cu2O/Ag CNFs show significantly improved SERS properties with an enhancement factor of similar to 10(5). Furthermore, the enhancement mechanism, reproducibility and stability of Cu2O/Ag CNFs are investigated in detail. The excellent properties of the prepared Cu2O/Ag CNFs suggest that this substrate has a potential application in SERS detection.