CoPt nanoparticles supported on a glassy carbon electrode (denoted as CoPt/GC) were prepared by galvanic replacement reaction between electrodeposited Co nanoparticles and K(2)PtCl(6) solution. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were both employed to characterize the CoPt nanoparticles. It was shown that the CoPt nanoparticles have irregular shapes and...

Composite nanostructure materials are widely used in catalysis. They exhibit several characteristics, such as the unique structural advantage and synergism among their components, which significantly enhances catalytic performance. In this work, CoPt nanoparticles reduced-graphene-oxide-based nanocomposite catalysts (rGO/CoPt, rGO/CoPt/Ag) were prepared by using a facile co-reduction strategy. ...

Monatomic (Fe, Co) and bimetallic (FePt and CoPt) nanoparticles were prepared by exploiting the self-organization of precursor loaded reverse micelles. Achievements and limitations of the preparation approach are critically discussed. We show that self-assembled metallic nanoparticles can be prepared with diameters d = 2-12 nm and interparticle distances D = 20-140 nm on various substrates. Str...

The dynamic response in a large experimental time window (10 –10 s) of Co and CoPt nanoparticle systems is reported. In order to reveal the dynamics effects, along with classic experiments as a.c. susceptibility and static magnetic measurements, a rf temperature dependent transverse susceptibility experiment is used. To study the effect of interaction between particles, samples of Co and CoPt n...

Large-scale first principles calculations for near-stoichiometric FePt and CoPt clusters with up to 923 atoms are presented including unconstrained structural relaxations. The energetic order and magnetic properties of 561 atom FePt and CoPt nanoparticles are evaluated with emphasis on segregated morphologies with Pt covered surfaces. The results imply that for CoPt particles segregation of Pt ...

Among many ferromagnetic materials, CoPt alloy nanoparticles with high coercivity and small grain size are one of the potential candidates having its application in high-density storage media manufacturing. CoPt alloy nanoparticles of different compositions have been prepared in TX-100 micellar medium and capped with sodium oleate to prevent the agglomeration during annealing at high temperatur...

Controlling the directed assembly of nanoparticles into welldefined nanoparticle superstructures is a significant challenge, and our goal is to develop a general methodology to address this issue. The success and broad applicability of a particular nanoparticle-assembly methodology should be assessed according to the following important criteria: 1) diverse structural scope, 2) ability to tune ...

Decreasing the cost associated with platinum-based catalysts along with improving their catalytic properties is a major challenge for commercial direct methanol fuel cells. In this work, a simple and facile strategy was developed for the more efficient preparation of multi-walled carbon nanotube (MWCNT) -supported Pt/CoPt composite nanoparticles (NPs) via solution plasma sputtering with subsequ...

A new electrochemical method to synthesize mesoporous nanowires of alloys has been developed. Electrochemical deposition in ionic liquid-in-water (IL/W) microemulsion has been successful to grow mesoporous CoPt nanowires in the interior of polycarbonate membranes. The viscosity of the medium was high, but it did not avoid the entrance of the microemulsion in the interior of the membrane's chann...

We propose an original route to prepare magnetic alloy nanoparticles with uniform size and shape by using nanosecond annealing under pulsed laser irradiation. As demonstrated here on CoPt nanoparticles, flash laser annealing gives an unprecedented opportunity to control the size and the shape of bimetallic nanoparticles without changing their composition. The mechanisms involved in the complete...