Shape-Controlled Synthesis of Dumbbell-like Pt–Fe₃O₄–MnO_x Nanoparticles by Governing the Reaction Kinetics

Abstract

The production of shape-controlled heterometallic nanoparticles (NPs) consisting of Pt and nonprecious metal oxides is crucial to demonstrate the composition–property relationship of NPs. Herein, we report a facile one-pot approach for the controlled synthesis of dumbbell-like Pt–Fe 3 O 4 –MnO x and dendritic Pt–MnO x NPs. The key to the success of this synthesis is in changing the quantity of Fe(CO) 5 additive to control the reaction kinetics. In the absence of Fe(CO) 5 , dendritic Pt–MnO x NPs were synthesized through the assembly of small seed NPs. On the other hand, dumbbell-like Pt–Fe 3 O 4 –MnO x NPs were obtained in the presence of Fe(CO) 5 through controlling the nucleation and growth of Fe and Mn on the Pt NPs, followed by air oxidation. Compared to a Pt/graphene oxide (GO) catalyst, dumbbell-like Pt–Fe 3 O 4 –MnO x NPs on GO showed an enhancement of specific activity toward the oxygen reduction reaction owing to the compressive-strain effect exerted on the Pt lattice.

Magnetite‐based Janus nanoparticles, their synthesis and biomedical applications

“…Further investigation of these heterostructures illustrated that these agents were efficient for two‐photon fluorescence (TPF) and magnetic resonance (MR) dual‐modal imaging via the combination of plasmonic and magnetic properties. Woo et al (2017) constructed dumbbell‐like Pt‐Fe 3 O 4 ‐MnOx through thermal decomposition of Fe(CO) 5 via nucleation and growth of Pt on Fe‐Mn. In the first step, Mn(acac) 2 and Fe(CO) 5 prepared Fe 3 O 4 ‐MnOx nanocubes as seeds, which were subsequently used to nucleate PtNPs at 200°C for 3 h and resulted in spherical‐concave cubic asymmetric structures.…”

Metal/semiconductor interfaces in nanoscale objects: synthesis, emerging properties and applications of hybrid nanostructures

“…281 The oxygen reduction reaction (ORR) is a reaction in the eld of batteries (Li-O 2 batteries, for example) 282 and fuel cells, 283 where an electrocatalyst (most commonly a precious metal) is responsible for the transformation of O 2 into H 2 O (in the case of Pt(100) the ORR is performed via the oxygen dissociation mechanism). 284 Using the interaction between the metal-oxide support and the metal, [285][286][287][288] the energetics of the catalyst can be improved. Meng et al have epitaxially grown Pt on single-crystal CuO NRs for this purpose.…”

Dumbbell-like Pt–Fe3O4 Nanoparticles Encapsulated in N-Doped Carbon Hollow Nanospheres as a Novel Yolk@Shell Nanostructure toward High-Performance Nanocatalysis

“…In particular, noble metal–Fe 3 O 4 heterostructures with typical dumbbell-like nanostructures have aroused great interest because of their outstanding optical, magnetic, and catalytic properties . For example, Au–Fe 3 O 4 dumbbell-like nanoparticles can be used as dual-functional probes, target-specific nanocarriers, and nanocatalysts. − Pt–Fe 3 O 4 dumbbell-like nanoparticles play a good catalytic role in redox reactions . However, they have some shortcomings such as being easily reunited and difficult to collect with poor reusability because of the small size of noble metal–Fe 3 O 4 dumbbell-like nanoparticles, magnetic components attracting each other, and other factors.…”

“…19−21 Pt−Fe 3 O 4 dumbbell-like nanoparticles play a good catalytic role in redox reactions. 22 However, they have some shortcomings such as being easily reunited and difficult to collect with poor reusability because of the small size of noble metal−Fe 3 O 4 dumbbell-like nanoparticles, magnetic components attracting each other, and other factors. Considering the high cost of noble metal nanoparticles and their practical applications, the development of an advanced architecture of noble metal−Fe 3 O 4 dumbbell-like nanoparticles with both improved catalytic activity and stability is highly desirable.…”