Fig. 2
From: Adsorption of copper (II) on mesoporous silica: the effect of nano-scale confinement
Adsorption isotherm plots showing the adsorption of Cu on mesoporous materials. a Cu adsorption on SBA-15-4. b Cu adsorption on SBA-15-6 and c Cu adsorption on SBA-15-8 fit with Langmuir, Freundlich and Dubinin–Radushkevich isotherm models