Introducing Ti-GERS: Raman scattering enhancement in graphene-mesoporous titania films

Carboni, D;Lasio, Barbara;Loche, Danilo;Casula, MARIA FRANCESCA;Mariani, Alberto;Malfatti, Luca;Innocenzi, Plinio

2015-01-01

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Abstract

Graphene sheets increase the Raman signal through a chemical enhancement mechanism that gives rise to graphene-mediated enhanced Raman scattering (GERS). The low enhancement factor and the surface available for analysis are, however, a limitation on the application of GERS. We have, therefore, developed a new GERS platform, which is based on mesoporous ordered films made of titania anatase containing dispersed sheets of exfoliated graphene. The analytical enhancement factor has revealed that the combination of titania and graphene produces a significant increase in GERS response using Rhodamine 6G as molecular probe. This is a new effect, which we have defined as Ti-GERS (titania-induced graphene-mediated ERS), and is attributed to synergic interfacial interactions between graphene sheets and titania at the nanocrystal edges within the nanocomposite. In the future, the Ti-GERS effect is expected to foster a development of better performing Raman-based analytical devices avoiding the use of expensive noble metals.