Interfacial self-assembled fabrication of petal-like CdS/ dodecylamine hybrids toward enhanced photoluminescence

Hierarchical TiO2/CdS "spindle-like" composite with high photodegradation and antibacterial capability under visible light irradiation

Novel hierarchical TiO(2)/CdS "spindle-like" composites with uniform distribution of CdS nanocrystals on nanoporous TiO(2) mesocrystals were successfully prepared by hydrothermal and hot-injection methods. In this work, the optimal mass ratio of Ti/Cd is determined to be 2 of as-synthesized TiO(2)/CdS composites. This TiO(2)/CdS composite exhibits excellent photocatalytic activity in the degradation of Rhodamine B (RhB) and photocatalytic reaction constant is 10 times higher than that of TiO(2), 3.5 times higher than that of CdS and higher than other TiO(2)/CdS composites with different amount of Ti/Cd mass ratio. In addition, TiO(2)/CdS with optimal amount of CdS kills 99.9% of Escherichia coli in 10 min under visible-light irradiation, which shows significant higher efficiency than pure TiO(2), CdS and other TiO(2)/CdS composites. The excellent performances of this hierarchical composite are ascribed to its outstanding properties, including large specific surface area (BET), high crystallinity of oriented single-crystal-like nanoporous TiO(2) mesocrystals for charge transfer, retarded recombination of photogenerated electron-hole pairs via isolating electrons and holes in two different materials, and extended photo response of this hierarchical composite to the visible region. Considering all these superior properties and abilities, this hierarchical TiO(2)/CdS "spindle-like" composite will show great potential for applications in the water purification field.

Room-temperature synthesis of self-assembled Sb2S3 films and nanorings via a two-phase approach

The freestanding Sb(2)S(3) films were easily synthesized at the interface of water and toluene at room temperature, where Na(2)S and (C(2)H(5)OCS(2))(3)Sb (xanthate, O-ethyldithiocarbonate) acted as sulfur and antimony source, respectively. After 3 h of aging, the Sb(2)S(3) films with a flat surface toward organic side and rough surface toward aqueous side were assembled by sheaflike Sb(2)S(3) nanowires. The Sb(2)S(3) nanorings formed by end-to-end connection of the bundled nanowires appeared in the water layer when the reaction time reached 24 h. The Sb(2)S(3) nanorings showed higher photocatalytic activity for methyl orange degradation under visible light than the Sb(2)S(3) films owing to broader spectrum response and better aqueous dispersion.

Controllable fabrication of nanocrystal-loaded photonic crystals with a polymerizable macromonomer via the CCTP technique

We report an alternative strategy for fabricating nanocrystal-loaded photonic crystals with a polymerizable macromonomer via catalytic chain-transfer polymerization (CCTP) in which CoBF acted as a chain-transfer agent (CTAs). First, monodisperse, functionalized PS-co-PMAA microspheres with polystyrene (PS) cores and poly(methacrylic acid) (PMAA) shells were controllably prepared using styrene and the as-prepared PMAA macromonomer by surfactant-free emulsion polymerization. Then Cd(0.4)Zn(0.6)S nanocrystals capped with as-prepared PMAA macromonomer were synthesized by an in situ growth method. Finally, Cd(0.4)Zn(0.6)S nanocrystal-loaded PS-co-PMAA microspheres hybrids were obtained through simply mixing an aqueous solution of PS-co-PMAA microspheres with an aqueous solution of Cd(0.4)Zn(0.6)S nanocrystals in the appropriate proportions; the multianchor -COOH groups on the surface of core-shell PS-co-PMAA microspheres favor incorporation with Cd(0.4)Zn(0.6)S nanocrystals. Scanning electron microscopy (SEM) images confirm that PS-co-PMAA microspheres are uniformly surrounded by Cd(0.4)Zn(0.6)S nanocrystals. In addition, discrete electronic and photonic states can be combined both with PS-co-PMAA photonic crystals and fluorescent semiconductor Cd(0.4)Zn(0.6)S nanocrystals.

Selective inclusion of anionic quantum dots in coordination network shells of nucleotides and lanthanide ions

Anionic quantum dots (QDs) are spontaneously enfolded by coordination networks self-assembled from nucleotide monophosphates and lanthanide ions in water; luminescent core-shell nanoparticles are specifically obtained for anionic QDs, which allows their separation from amine-modified QDs.