Graphene/TiO2 hybrid layer for simultaneous detection and degradation by a one-step transfer and integration method

During the past decades, researchers have made great efforts towards an ideal surface enhanced Raman spectroscopy (SERS) substrate. Here a smart SERS-active flexible substrate was designed and its performance was studied. The substrate is constructed from graphene and TiO2, and could be divided into two functional layers. Graphene provides a flat hot surface for Raman enhancement, which could be ascribed to chemical enhancement. The TiO2 layer is an effective photocatalyst, which could induce photocatalytic decomposition of adsorbed molecules under UV irradiation. Notably, the substrate was realized by a one-step transfer method, followed by annealing. In the synthesis process, a flexible TiO2 layer was produced by spin-coating on the CVD graphene and was used as a support in the transfer process of graphene instead of PMMA, which could exclude contamination and avoid degradation of the Raman enhancement performance. Combining detection with degradation of trace amounts of analyte, the versatility of the SERS substrate is greatly enhanced and could be adapted to fit a wide range of sensing and photocatalytic applications.