Study on the chemisorption kinetics of Methylene Blue using SERS technique

SERS technique was used to study the chemisorption kinetics of Methylene Bl ue (MB) on the HNO3-etched silver surface. The adsorption kinetic parameter s were deduced from different vibrational modes at a low concentration of 3 .5 x 10(-6) mol/L, and it showed that MB adsorbed uniformly (monolayerly) o n silver surface. However, the adsorptive behavior turned anomalous at rela tively higher concentrations and a possible explanation was suggested. In a ddition, the influence of Cl- ions on the adsorption states of MB was inves tigated, and it was shown that MB molecules, adsorbed on the silver surface , tended to transform from the "lying-down" state to the "end- on" 4 state after Cl- ions were added.