Self‐Assembled Platinum Nanochain Networks Driven by Induced Magnetic Dipoles

Abstract

Developing a reliable technique to organize nanoscale building blocks into ordered one‐dimensional assemblies is of particular interest in a range of practical applications. Here, for the first time, it is reported that platinum (Pt) nanoparticle chain networks can be assembled spontaneously in solution on a large scale. The in‐situ induced magnetic dipoles are believed to be the driving force for producing such elegant assembled nanochains. The alterant electronic structure of Pt modified by a very thin layer of polyvinylpyrrolidone (PVP) molecules leads to the ferromagnetism of Pt (a traditional paramagnetic metal), which has been verified by a series of analysis techniques and theoretical modeling. The temperature‐ and time‐dependent nucleation, growth, and organization processes of Pt chain networks are carefully investigated. These findings not only present the uncommon ferromagnetism of Pt, but also raise a possibility for expanding this strategy towards other assemblies of nonmagnetic nanoscale building blocks.

Interparticle Forces Underlying Nanoparticle Self‐Assemblies

“…Gao et al modified Pt nanoparticles, a traditional paramagnetic metal, to ferromagnetism by applying a thin polyvinylpyrrolidone (PVP) molecules layer. Magnetic dipole–dipole interactions drive Pt nanoparticles to self‐assemble into chain networks . Wang et al fabricated necklace‐like nanorings composed of 40 nm magnetic nanoparticles.…”

Synthesis and magnetic properties of organic multilayer films based on the layer‐by‐layer assembly

“…[26] The design and preparation of organic ferromagnets is one of the great challenges in the fields of molecular-based magnetic materials. [27][28][29][30] Varieties of complexes containing novel synthetic polymers with nitrogen atoms or oxygen atoms and the corresponding complexes with transition metal ions or rare earth metal ions have been synthesized based on complicated chemical reactions. [31][32][33][34] Most of these polymers show interesting magnetic behaviors.…”

Arginine-assisted synthesis of palladium nanochain networks and their enhanced electrocatalytic activity for borohydride oxidation

“…[1][2][3][4][5][6][7][8][9][10][11][12] Currently, various PMNs with different morphologies have been successfully prepared, including zero-dimensional (0D) nanostructures (e.g., spheres and polyhedrons), 1, 2 one-dimensional (1D) nanostructures (e.g., rods and wires/chains) 3,4 and twodimensional (2D) nanostructures (e.g., discs and plates). 8,9 Of particular interest are three-dimensional (3D) network nanostructures consisting of 1D nanochains/wires due to their large surface area and outstanding mass transfer efficiency compared with 0D nanostructures, 4-7, 13, 14 which endow the PMNs with improved activity and stability for many important catalytic/electrocatalytic reactions.…”

“…15,16 Thanks to the efforts from many research groups, several significant progresses with regard to 3D nanostructures have been developed using different strategies. [4][5][6][7] For example, Xia and coworkers successfully synthesized ultrathin Pd nanowires by using the polyol method without the involvement of any template, which exhibited superior electrocatalytic activity for the formic acid oxidation reaction. 4 More recently, the self-assembled Pt nanochain networks were also successfully prepared in polyvinylpyrrolidone (PVP) solution using in-situ induced magnetic dipoles strategy.…”

“…4 More recently, the self-assembled Pt nanochain networks were also successfully prepared in polyvinylpyrrolidone (PVP) solution using in-situ induced magnetic dipoles strategy. 5 To the best of our knowledge, little research focuses on the interrelationship between the formation mechanism of nanochains/wires and the functional groups of structure directing agent employed.…”