High performance polydopamine-functionalized mesoporous silica nanospheres for U(VI) removal

Autor: Min Sang, Linfeng Bai, Xinglong Gong, Jiaxing Li, Mei Liu, Sheng Wang, Shengxia Duan, Wanquan Jiang, Shouhu Xuan
Rok vydání: 2017
Předmět:
Zdroj: Applied Surface Science. 426:1121-1132
ISSN: 0169-4332
DOI: 10.1016/j.apsusc.2017.07.274
Popis: This work reports the fabrication of polydopamine-functionalized mesoporous silica (mSiO 2 /PDA) nanospheres for removing U(VI) from aqueous solution. The maximum adsorption capacity of mSiO 2 /PDA is 332.3 mg/g at 318.15 K and pH = 5.5. In comparison to the pristine mSiO 2 , the adsorption capacity of mSiO 2 /PDA has been remarkably enhanced, which can be ascribed to the large amounts of functional groups existed on the surface of mSiO 2 /PDA. The adsorption process fits well with the pseudo-second-order kinetics model. The adsorption isotherm follows the Langmuir isotherm model, revealing a monolayer adsorption of U(VI) onto mSiO 2 /PDA. Thermodynamic analysis indicates a spontaneous and endothermic adsorption process. Additionally, this adsorption process is pH-dependent, while the effect of ionic strength is negligible.
Databáze: OpenAIRE