New composite material provides triple-pure water

Scientists have developed an all-in-one water-decontamination material—a powder made from a polyoxometalate-based ionic liquid adsorbed onto a porous silica support. The composite material does the job traditionally tackled by a combination of filtration materials: It removes organics, kills microorganisms, and captures heavy metals (Angew. Chem. Int. Ed. 2017, DOI: 10.1002/anie.201611072). The material’s developers, led by Carsten Streb of the University of Ulm and Scott G. Mitchell of the University of Zaragoza, hope it could be a start to developing easily transportable water-purification systems for remote areas with limited or contaminated water. Streb’s lab has specialized in polyoxometalate-based ionic liquids. In this case, the researchers created a supported ionic liquid phase, or SILP, using an ionic liquid made with polyoxotungstate anions and tetraalkylammonium cations adsorbed onto silica. In lab experiments, they demonstrated the multitasking abilities of the resulting free-flowing powder. The polyoxotungstate anion binds heavy-metal ions, including nickel and lead, with the silica support further trapping radioactive uranyl ions. In addition, the composite material is lipophilic and so adsorbs organic compounds, such as trityl dyes. And the tetraalkylammonium cations are antimicrobial and thus inhibit harmful bacteria, such as Escherichia coli.