Synthesis of self-assembled hierarchical AlPO-34 microspheres by using an ionic liquid and its application in heavy metal removal

Hierarchical AlPO-34 molecular sieves microspheres were synthesized in a [BMIm]Br ionic liquid without template or complex post-treatment process. The formation mechanism of such framework structures and their morphology were investigated. [BMIm]Br was proven to serve as both solvent and sole provider of the structure directing agent. The organic amine in the compound affects the framework density of the crystals and promotes the formation of a chabazite (CHA) type framework. After ageing for 1 h the AlPO-34 microspheres are formed due to the aggregation properties of the ionic liquid. The hierarchical mirosphere has a relatively high Brunauer-Emmett-Teller surface area and a considerably uniform mesoporous channel network. The hierarchical AlPO-34 microspheres were used as absorbers of heavy metal cations and showed a higher loading capacity and distribution coefficient compared with the AlPO-34-NH.

Automated summary

Hierarchical AlPO-34 molecular sieves microspheres were successfully synthesized in a [BMIm]Br ionic liquid without the need for a template or complex post-treatment process. The [BMIm]Br was shown to act as both a solvent and a structure directing agent. The organic amine in the compound affected the framework density of the crystals and promoted the formation of a chabazite (CHA) type framework. The resulting microspheres had a high surface area and a uniform mesoporous channel network.