Surface-enhanced Raman spectroscopic activity on bare nickel electrode roughened by electrochemical method

Surface-enhanced Raman scattering (SERS) active Nickel electrode was roughened by electrochemical potential step technique combined with cyclic voltammetry (CV) in 0.5 mol/L NaClO4 solution. It could be seen from the SEM images that uniform and nanometer level Ni particles which might induce an optimal SERS activity were produced on the Ni surface. Meanwhile, the studies of potential-dependent SERS of pyridine revealed that pyridine was interacted with Ni surface via N atom vertically because of the observation of in-plane vibration mode and Ni-N stretching vibration. Furthermore, the roughness factor of the Ni electrode was measured by comparing the differential capacitance of roughened surface with mechanical polished smooth surface, and thus the surface-enhancement factor (SEF) of the roughened Ni electrode was calculated in the range of about four orders, and it was one to two orders larger than that reported by the previous surface pretreatments.