Graphene Grown on Ni Foam: Molecular Sensing, Graphene-Enhanced Raman Scattering, and Galvanic Exchange for Surface-Enhanced Raman Scattering Applications
The growing of graphene on irregular 3D Ni structure demonstrates to be aninteresting platform for, molecular sensing, GERS, and SERS applications after galvanicexchange of Ag + ions. Raman, SEM (EDS), optical images, and diffuse reflectance exhibitthat graphene grows in multilayer (MLG) fashion with different stacking configurations.Statistics performed employing Raman show that as-grown graphene can be classified intwo main stacking configurations: AB (or Bernal stacking) and rotated graphene which areseparated by a 2D full-width half maximum (fwhm) threshold of ~30 cm -1 . Rotatedstacking senses low concentrations of methylene blue (MB) at 10 -6 M concentration,whereas AB-stacking seems to be much less sensitive upon molecular adsorption. Galvanicexchange of Ag leads to agglomerates preferentially formed on top graphene wrinkleswhich ultimately became target-spots for performing SERS. Our experiments demonstratethat as-grown graphene, comprised of different stacking configurations, can be used as amolecular sensor and detect nanomolar concentrations of MB and thiram (by SERSapplications), after galvanic exchange with Ag.Centro de Química InorgánicaInstituto de Investigaciones Fisicoquímicas Teóricas y AplicadasConsejo Nacional de Investigaciones Científicas y Técnica
