Leptothrix species, one of the Fe/Mn-oxidizing bacteria, oxidize Fe(II) and produce extracellular, microtubuar, Fe-encrusted sheaths. Since protein(s) involved in Fe(II) oxidation is excreted from Leptothrix cells, the oxidation from Fe(II) to Fe(III) and subsequent Fe(III) deposition to sheaths have been thought to occur in the vicinity or within the sheaths. Previously, Fe(III) particles gene...

Nanoscale zerovalent iron (NZVI) particles are 5–40 nm sized Fe/Fe-oxide particles that rapidly transform many environmental contaminants to benign products and are a promising in situ remediation agent. Rapid aggregation and limited mobility in water-saturated porous media limits the ability to deliver NZVI dispersions in the subsurface. This study prepares stable NZVI dispersions through phys...

The systematic assembly of nanoscale constituents into highly ordered superlattices is of significant interest because of the potential of their multifunctionalities and the discovery of new collective properties. However, successful observations of such superlattice-associated nanoscale phenomena are still elusive. Here, we present magnetic superlattices of Co and Fe(3)O(4) nanoparticles with ...

Nanoscale particles are known to exhibit novel and unprecedented properties that make them quite different from their corresponding bulk-scale materials. The key differences are (i) an increased relative surface area and (ii) quantum size effects. Since the growth, catalytic activity and the various interactions with molecules (including biomolecules) occur at the surface of nanoparticles, a gi...

Nanoscale, zero-valent iron is a promising reagent for in situ reduction of a variety of subsurface contaminants, but its utility in full-scale remediation projects is limited by material costs. Iron nanoparticles (20-100 nm diameter) supported on carbon (C-Fe0) were synthesized by reacting iron salts, adsorbed or impregnated from aqueous solutions onto 80 m2/g carbon black, at 600-800 degrees ...

OBJECTIVE To investigate reductive dechlorination of 4-chlorophenol (4-CP) by nanoscale Fe0 under different conditions. METHODS Nanoscale Fe0 was synthesized by using reductive method. 4-CP and its intermediate products were analyzed by HPLC. Chlorine ion was quantified with DX-100 ion chromatograph. Nano-iron particles were observed under a FEI Quanta 200 FEG environmental scanning electron ...

A new type of spindle-shaped nanoscale yolk/shell magnetic stirring bar containing noble metal nanoparticles was prepared. The as-synthesized Pd-Fe@meso-SiO2 not only showed impressive activity and stability as a heterogeneous catalyst in a macroscopic flask system, but also acted as an efficient nanoscale magnetic stir bar in a microscopic droplet system.

Reactions of aqueous Fe(II) with Fe and Mn oxides influence heavy metal mobility, transformation of trace organics, and important elemental cycles as Fe precipitates form or dissolve, and as electrons move between aqueous and solid phases. Our objective was to characterize reactions of Fe(II) with important metal oxides, using a suite of complementary tools to investigate the extent and underly...

The evolution of nano-scale Fe particles precipitated in a Cu–Fe alloy has been examined from the viewpoint of the relationship between the microstructure and magnetic properties, using conventional, high-resolution and Lorentz electron microscopy, and magnetic measurements. It has been revealed that spherical Fe particles have a tendency to align along the <001> direction in a Cu matrix at the...

Fe(3)O(4) nanoprisms, synthesized by a solvothermal process, exhibited crystal plane dependent electrochemical activities, which opens an approach to nanoscale materials with controlled electrochemical properties.