浓度对活性艳红染料在粗糙银表面上吸附的影响

Effect of Concentration on the Absorption of Reactive Red on Silver Surface

利用化学还原的方法制备了银溶胶 ,通过测定活性艳红浓度从 1 0 -4 — 1 0 -8m ol/L在粗糙的银表面上的表面增强拉曼光谱的变化 ,探讨了活性艳红浓度与表面增强拉曼强度的关系及活性艳红在银溶胶表面的吸附取向。结果表明 ,活性艳红在 1 0 -5mol/L时 ,表面增强拉曼信号最强 ,说明在此浓度时 ,活性艳红在银溶胶上的吸附量达到饱和 ;而大于此浓度后 ,过量的活性艳红分子在银溶胶上发生叠加 ,拉曼信号减弱 ,这种现象符合“稀溶液效应”

SERS spectra of reactive red absorbed on a silver colloid were measured by a Jobin-Yvon Raman spectrometer.By varying the concentration of reactive red from 10 -4-10 -8mol/L,the relationship between the concentration and intensity has been studied.It is found that the intensity reaches to a maximum value as the concentration of reactive red is 10 -5mol/L.The mechanism for this phenomenon is discussed.