Thermodynamics and kinetics of Cu2+ adsorption of organic-inorganic hybrid hollow mesoporous silica spheres

In this work, organic–inorganic hybrid hollow mesoporous silica spheres (HMSs) have been synthesized by a core-template-free microemulsion method, and the thermodynamic and kinetic of the adsorption process of Cu2+ on the HMSs are detailly investigated. Thermodynamic results showed that the adsorption process obeyed the Langmuir model with a maximum adsorption capacity of 52.0 mg/g. Kinetic studies fitted well with the pseudo-second-order model, and the intraparticle diffusion model showed that the interparticle diffusion is not the sole adsorption rate-limiting step, the adsorption process was jointly controlled by both the external surface attraction interaction and interparticle diffusion interaction between the HMSs and Cu2+. The adsorption capacity of different HMSs is highly depended on the surface charge and their BET surface area. These experimental results provide some theoretical guidance for the metal ions adsorption on the HMSs.