Premium
Dealloying Ag–Al Alloy to Prepare Nanoporous Silver as a Substrate for Surface‐Enhanced Raman Scattering: Effects of Structural Evolution and Surface Modification
Author(s) -
Qiu Huajun,
Zhang Zhonghua,
Huang Xirong,
Qu Yinbo
Publication year - 2011
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201100205
Subject(s) - nanoporous , raman scattering , materials science , substrate (aquarium) , alloy , surface modification , raman spectroscopy , nanotechnology , chemical engineering , scattering , surface (topology) , metallurgy , optics , oceanography , physics , engineering , geology , geometry , mathematics
Abstract Sensitive detection of molecules by using the surface‐enhanced Raman scattering (SERS) technique depends on the nanostructured metallic substrate and many efforts have been devoted to the preparation of SERS substrates with high sensitivity, stability, and reproducibility. Herein, we report on the fabrication of stable monolithic nanoporous silver (NPS) by chemical dealloying of Ag–Al precursor alloys with an emphasis on the effect of structural evolution on SERS signals. It was found that the dealloying conditions had great influence on the morphology (the ligament/pore size) and the crystallization status, which determined the SERS signal of rhodamine 6G on the NPS. NPS with small pores, low residual Al, and perfect crystallization gave high SERS signals. A high enhancement factor of 7.5×10 5 was observed on bare NPS obtained by dealloying Ag 30 Al 70 in 2.5 wt % HCl at room temperature followed by 15 min aging at around 85 °C. After coating Ag nanoparticles on the NPS surface, the enhancement factor increased to 1.6×10 8 owing to strong near‐field coupling between the ligaments and nanoparticles.