Fabrication of a New Hydrous Zr(IV) Oxide-Based Nanocomposite for Enhanced Pb(II) and Cd(II) Removal from Waters

To overcome the technical bottleneck of fine hydrated Zr­(IV) oxide particles in environmental remediation, we irreversibly impregnated nanosized hydrated Zr­(IV) oxide inside a commercial cation exchange resin D-001 and obtained a new nanocomposite NZP. NZP exhibited efficient removal of lead and cadmium ions in a pH range of 2–6, where no Zr­(IV) leaching was detected from NZP. As compared to D-001, NZP showed more preferable adsorption toward both toxic metals from the background Ca­(II) solution at greater levels. The synthetic Pb­(II) or Cd­(II) solution containing other ubiquitous metal ions was employed as the feeding influent for column adsorption, and the results indicated that the treatable volume of NZP is around 3–4 times that of D-001 before reaching the breakthrough point set according to the effluent discharge standard of China. With respect to Pb­(II) removal from an acidic mining effluent, the treatable volume of NZP was 13 times higher than that of D-001. The exhausted NZP could be effectively regenerated by HNO₃–Ca­(NO₃)₂ binary solution for repeated use without any significant capacity loss. The superior performance of NZP was attributed to the Donnan membrane effect exerted by the host D-001 as well as the impregnated HZO nanoparticles of specific interaction toward toxic metals, as confirmed by the comparative isothermal adsorption and X-ray photoelectron spectroscopic study

Fluorescence-Magnetism Functional EuS Nanocrystals with Controllable Morphologies for Dual Bioimaging

Multiple functions incorporated in one single component material offer important applications in biosystems. Here we prepared a divalent state of rare earth EuS nanocrystals (NCs), which provides luminescent and magnetic properties, using both 1-Dodecanethiol (DT) and oleylamine (OLA) as reducing agents. The resultant EuS NCs exhibit controllable shapes, uniform size, and bright luminescence with a quantum yield as high as 3.5%. OLA as a surface ligand plays an important role in tunable morphologies, such as nanowires, nanorods, nanospheres et al. Another attractive nature of the EuS NCs is their paramagnetism at room temperature. In order to expand the biological applications, the resultant EuS NCs were modified with amphiphilic block copolymer F127 and transferred from oil to water phase. The excellent biocompatibility of EuS NCs is demonstrated as well as preservation of their luminescence and paramagnetic properties. The EuS NCs offer multifunction and great advantages of bright luminescence, paramagnetic, controllable morphologies, and good biocompatibility promising applications in the field of simultaneous magnetic resonance and fluorescence bioimaging