title: Surface-Functionalized Electrospun Titania Nanofibers for the Scavenging and Recycling of Precious Metal Ions.
abstract: Precious metals are widely used as catalysts in industry. It is of critical importance to keep the precious metal ions leached from catalysts at a level below one part per million (ppm) in the final products and to recycle the expensive precious metals. Here we demonstrate a simple and effective method for scavenging precious metal ions from an aqueous solution and thereby reduce their concentrations down to the parts per billion (ppb) level. The key component is a filtration membrane comprised of titania (TiO2) nanofibers whose surface has been functionalized with a silane bearing amino or thiol group. When operated under continuous flow at a rate of 1 mL min-1and at room temperature, up to 99.95 % of the Pd2+ions could be removed from a stock solution with an initial concentration of 100 ppm. This work offers a viable strategy not only for the removal of precious metal ions but also for recovering and further recycling them for use as catalysts. For example, the captured Pd2+ions could be converted to nanoparticles and used as catalysts for organic reactions such as Suzuki coupling in a continuous flow reactor. This system can be potentially applied to pharmaceutical industry and waste stream treatment.
authors.affiliation: Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
authors.forename: Yunqian
authors.initials: Y
authors.lastname: Dai
authors.affiliation: Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Formo
authors.affiliation: The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA.
authors.forename: Haoxuan
authors.initials: H
authors.lastname: Li
authors.affiliation: The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA.
authors.forename: Jiajia
authors.initials: J
authors.lastname: Xue
authors.affiliation: Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA. younan.xia@bme.gatech.edu.|The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA. younan.xia@bme.gatech.edu.
authors.forename: Younan
authors.initials: Y
authors.lastname: Xia
mesh_terms: D002412:Cations; D055664:Electrochemical Techniques / Q000379:methods*; D008670:Metals; D008855:Microscopy, Electron, Scanning; D057139:Nanofibers / Q000737:chemistry*; D059027:Recycling; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D002412:Cations; D008670:Metals; D014025:Titanium
keywords: cross-coupling; nanotechnology; palladium; recycling; scavenging