Mesoporous silica (KIT-6) derivatized with hydroxyquinoline functionalities as a selective adsorbent of uranium(VI)

Abstract

Two modified mesoporous silica (KIT-6) materials for absorbing uranium(VI) were prepared respectively via post-grafting of 8-hydroxyquinoline and 8-hydroxyquinoline onto surface of KIT-6, which were characterized by FT-IR, NMR, TEM, and sorption/desorption analysis. Effect of pH values, contact time, ionic strength, solid-liquid ratio, temperature, and coexisting ions on sorption behavior of the modified KIT-6 were also investigated. Typical sorption isotherms (Langmuir and Freundlich) were used to determine the sorption process and the maximum U(VI) sorption capacity. The results indicate that the two modified KIT-6 exhibit better selective sorption of U(VI) as compared to the original KIT-6.

Rapid Room-Temperature Preparation of Hierarchically Porous Metal–Organic Frameworks for Efficient Uranium Removal from Aqueous Solutions

“…During the first 30 min, the uptake of uranium (VI) by RT-Cu-BTC increased rapidly with an increase of contact time, and a large amount of uranium (VI) was removed, which can be attributed to the higher concentration gradient of uranium (VI) and more available active sites of adsorbent during this period [30]. Subsequently, the adsorption capacity of RT-Cu-BTC showed a steadily increasing trend within 30-120 min as the active sites of the adsorbent gradually reached saturation [32]. After 120 min, the adsorption reached equilibrium, and the maximum adsorption capacity and adsorption efficiency were 839.7 mg•g −1 and 99.8%, respectively.…”

Adsorption study of toxic metal ions using functionalized 3D mesostructured silica

“…In this context, for further increase the adsorption capability, chemical modification of pore walls surface of mesoporous silica by organic functional groups via either co-condensation or post-grafting methods were applied [39][40][41][42][43][44][45]. Although, several studies investigated the utilization of organic active groups functionalized mesoporous silica materials as promising adsorbents [46][47][48][49][50][51][52], a few reports have been demonstrated for the use of functionalized KIT-6 [53][54][55][56][57][58][59].…”

Flow-enhanced kinetics of uranyl (UO2) transport into nano-porous silica gel

“…The equilibrium capacity refers to the total number of silica surface sites available to adsorb a uranyl ion, while the kinetics of adsorption is the time required to fill those sites. Study of equilibrium capacity has focused on maximizing the capacity for removing ions from aqueous solutions [17][18][19][20]. The maximization of the equilibrium capacity was achieved by adding functional groups to the surface of the silica gel particles [17,[19][20][21][22].…”