ZnO nanowire arrays decorated with titanium nitride nanoparticles as surface-enhanced Raman scattering substrates

In this work, the potential of ZnO nanowire arrays decorated with titanium nitride (TiN) nanoparticles as surface-enhanced Raman scattering (SERS) substrates is demonstrated. ZnO nanowires were grown by hydrothermal synthesis while commercially obtained TiN powders were subjected to several hours of mechanical grinding to achieve 30-100 nm diameter nanoparticles. The nanoparticles were then dispersed in acetone and drop cast on the ZnO nanowire arrays for decoration. Scanning electron microscopy confirmed the presence of TiN nanoparticles on the ZnO nanowires. TiN nanoparticles exhibited multiple absorption features at 430, 520 and 600 nm. SERS experiments using Nile blue and methylene blue as the analyte molecules exhibited enhancement in the Raman signals. It is shown that the origin of the SERS effect is chemical in nature, with contribution from different interactions between the analyte molecule and the TiN nanoparticles. The current work, thus, represents a simple, cost-effective and facile method for the fabrication of TiN-based SERS substrates.