The heavy metal ions pollution has attracted tremendous attention owing to their cumulative effect in organs. In this work, ZnS coated upconversion nanoparticles (denoted as UCNPs@ZnS) has been fabricated and firstly used as dual-functional fluorescence probe for simultaneously removal of heavy metals such as Ag + , Cu 2+ or Hg 2+ and detection of these ions residual in aqueous solution.. The upconversion fluorescence intensity of the UCNPs@ZnS suspension solution was quenched gradually with the addition of the Ag + , Cu 2+ or Hg 2+ aqueous solution, which is attributed to the formation of highly insoluble metal sulfides with narrower band-gap with enhanced fluorescence resonance energy transfer (FRET) efficiency. 3.98 µmol Ag + can be removed completely in presence of 1 mg UCNPs@ZnS core-shell nanoparticles. In addition, removal amount of Ag + is proportional to the changes of the upconversion fluorescence intensity of the UCNPs@ZnS core-shell nanoparticles suspension solution. Therefore, this work could be extended to monitor and remove these heavy metal ions whose sulfides are less soluble than ZnS.
Jundiao Wang,Haoran Ning,Jun Wang,Stephen V. Kershaw,Lihong Jing,Pan Xiao
Semiconductor quantum dots (QDs) are promising materials for stress/strain sensing applications owing to their pressure-dependent photoluminescence (PL) and nanoscale size, while the impact of stress and microstructure on their optical properties still awaits in-depth investigations under more realistic loading conditions. Herein, bare CuInS2 QDs and core–shell structured CuInS2/ZnS QDs are investigated under repetitive pressure loadings to elucidate the pressure-dependent PL responses over many pressure cycles. The CuInS2/ZnS QDs not only show higher PL intensity but also exhibit a reliable and simple relationship between PL emission peak energy (EPL) and external pressure (P), which is desirable for actual application in stress/strain sensing. Specifically, the EPL–P relationship of bare CuInS2 QDs changes after the first loading–unloading cycle, while the EPL–P relationship of CuInS2/ZnS QDs shows repeatable trajectories under different cycles. This research provides experimental support for designing QD-based stress/strain sensing materials and explains how the shell and surface microstructure will affect the mechanical-luminescence responses of QDs.
危险品化学品经营许可证（带存储）