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Preparation of silver nanoparticles on zinc oxide nanowires by photocatalytic reduction for use in surface‐enhanced Raman scattering measurements
Author(s) -
Chen ICherng,
Liou YenChen Maggie,
Yang Jyisy,
Shieh TienYu
Publication year - 2011
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.2727
Subject(s) - raman scattering , silver nitrate , zinc , silver nanoparticle , raman spectroscopy , materials science , nanowire , ultraviolet , irradiation , photocatalysis , zinc nitrate , nanoparticle , chemical engineering , nanotechnology , oxide , chemistry , nuclear chemistry , optoelectronics , metallurgy , catalysis , optics , physics , engineering , nuclear physics , biochemistry
To increase the sensitivity in surface‐enhanced Raman scattering (SERS) measurements, the high surface area of zinc oxide nanowires (ZnO NWs) was used. ZnO NWs on silicon substrates were prepared and used as substrates for further growth of silver nanoparticles (AgNPs). Ultraviolet (UV) irradiation was used to reduce silver ions to AgNPs on the ZnO wires. With proper growth conditions for both ZnO NWs and AgNPs, the substrates exhibit SERS enhancement factors greater than 10 6 . To understand the influences of the morphologies of the ZnO NWs on the growth of AgNPs, the growing time and temperature were varied. The concentration of silver nitrate and irradiation time of UV radiation were also varied. The resulting AgNPs were probed with para ‐nitrothiophenol to quantify the SERS enhancements obtained from the varying conditions. The results indicate that ZnO NWs could be grown at temperatures higher than 490 °C and higher growth temperatures result in smaller diameter of the formed ZnO NWs. Also, the morphologies of ZnO NWs did not significantly alter the SERS signals. The concentration of silver nitrate affects the SERS signals significantly and the optimal concentration was found to be in the range of 10–20 mM. With irradiation times longer than 90 s, the resulting AgNPs showed similar SERS intensities. With optimized conditions, the AgNPs/ZnO substrates are highly suitable for SERS measurements with a typical enhancement factor of higher than 10 6 . Copyright © 2010 John Wiley & Sons, Ltd.