No abstract

No abstract

Uniform urchin-like α-FeOOH hollow spheres assembled from nanoneedles have been synthesized via a facile and green one-pot method. By simply adjusting the amount of glycerol in the reaction system, hierarchical urchin-like α-FeOOH solid spheres or hollow spheres can be obtained. When evaluated for the potential use in water treatment, it is found that the as-obtained uniform urchin-like α-FeOOH hollow spheres exhibit excellent capability for removing both organic dye and heavy metal ions in waste water.

No abstract

We report a new strategy to synthesize core-shell metal nanoparticles with an interior, Raman tag-encoded nanogap by taking advantage of nanoparticle-templated self-assembly of amphiphilic block copolymers and localized metal precursor reduction by redox-active polymer brushes. Of particular interest for surface-enhanced Raman scattering (SERS) is that the nanogap size can be tailored flexibly, with the sub-2 nm nanogap leading to the highest SERS enhancement. Our results have further demonstrated that surface functionalization of the nanogapped Au nanoparticles with aptamer targeting ligands allows for specific recognition and ultrasensitive detection of cancer cells. The general applicability of this new synthetic strategy, coupled with recent advances in controlled wet-chemical synthesis of functional nanocrystals, opens new avenues to multifunctional core-shell nanoparticles with integrated optical, electronic, and magnetic properties.

No abstract

No abstract

Monochlorobenzene (MCB), dichlorobenzenes (DCBs), and 1,2,4-trichlorobenzene (124TCB) dechlorination experiments in water were carried out with freshly synthesized Pd/Fe particles. The pre- and postreacted Pd/Fe samples were characterized by applying various analytical techniques (XRD, SEM, TEM, and XPS). Chlorinated benzenes could be completely reduced by the Pd/Fe to benzene and the reaction followed the pseudo-first-order kinetics. The reaction rates followed the order TCB < DCBs < MCB, while among the DCBs the order was 1,4-dichlorobenzene >1,3-dichlorobenzene > or = 1,2-dichlorobenzene. Insignificant reactions were observed with the unpalladized iron, suggesting that Pd was the only reactive site in the Pd/Fe particles. The aged Pd/Fe particles exhibited significant decrease in its dechlorination reactivity. The loss of Pd/Fe reactivity could be due to Pd dislodgment from the aged Pd/Fe particles and Pd islets encapsulation by the iron oxides film developed over aging period. Reactivity of the aged Pd/Fe could be only partially restored after HCI treatment, while regeneration with the NaBH4 reduction method could not restore its activity, although zerovalent state of the iron was reinstated.