title: Controlled photocatalytic growth of Ag nanocrystals on brookite and rutile and their SERS performance.
abstract: Ag nanocrystals (NCs) were photocatalytically grown on the surfaces of brookite and rutile nanocrystals, respectively, and their surface-enhanced Raman scattering (SERS) performance was evaluated. The resultant Ag NCs exhibit different morphologies owing to the different photocatalytic capabilities of the two types of TiO2 under otherwise identical synthetic conditions. The effects of AgNO3 concentration, UV irradiation time, and UV light power on the morphology evolution and growth kinetics of the Ag NCs were systematically investigated. Moreover, PVP was found to serve as both a reductant and a capping agent in the photocatalytic reaction systems, and its presence allows morphological control of the Ag NCs. A proper amount of PVP was confirmed to favor Ag nanoplates of larger sizes and to produce SERS substrates of substantially better performance.
authors.affiliation: Key Laboratory for Anisotropy and Texture of Materials, School of Materials and Metallurgy, Northeastern University , Shenyang 110819, China.
authors.forename: Tian-Long
authors.initials: TL
authors.lastname: Guo
authors.forename: Ji-Guang
authors.initials: JG
authors.lastname: Li
authors.forename: De-Hai
authors.initials: DH
authors.lastname: Ping
authors.forename: Xudong
authors.initials: X
authors.lastname: Sun
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Sakka