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The large-scale and efficient synthesis of MnPO4·H2O is an urgent problem to be solved. In this paper, self-assembled dumbbell-shaped MnPO4·H2O particles were successfully synthesized just using KMnO4 and commercial concentrated H3PO4, and then employed as the precursor to prepare LiMnPO4/C composites. The XRD, SEM, TEM, and electrochemical performance tests were used to investigate MnPO4·H2O and the corresponding LiMnPO4/C. The formation mechanism of MnPO4·H2O was discussed. The results showed that temperature and water content have a significant effect on the yield, purity, and morphology of MnPO4·H2O. The synthesized LiMnPO4/C with reduced carbon content at 650 °C delivered a discharge capacity of 109.3 mA h g-1 at 1 C and 104.3 mA h g-1 at 2 C. This green and efficient synthesis method of MnPO4·H2O provides a new idea for the large-scale preparation of LiMnPO4/C cathode materials.

Noble metal-Fe3O4 dumbbell-like nanoparticles have aroused considerable attention because of their high potential as heterogeneous nanocatalysts. The designed synthesis of the advanced architecture of noble metal-Fe3O4 dumbbell-like nanoparticles with both improved catalytic activity and stability is still a challenge. Herein, through the combination of yolk@shell and dumbbell-like nanostructures, dumbbell-like Pt-Fe3O4 nanoparticles encapsulated in N-doped carbon hollow nanospheres (Pt-Fe3O4@N-carbon) as a special yolk@shell nanostructure were developed. In comparison with Pt-Fe3O4 dumbbell-like nanoparticles, Pt-Fe3O4@N-carbon yolk@shell nanoparticles showed improved catalytic activity and stability toward the liquid-phase 4-nitrophenol reduction and β-ionone oxidation, making them a promising candidate for catalysis applications.

A novel method for the synthesis of dumbbell-like amine-functionalized bis-C60 fullerene from simple bis-α-silyl tertiary benzyl amines and C60 fullerene is described. The photoreactions between bis-α-silyl tertiary benzyl amines and C60 furnished single-bonded bis-aminomethyl-1,2-dihyrofullerenes and double-bonded 1,2,5-trisubstituted bis-fulleropyrrolidines through 1,3-dipolar cycloaddition reactions of azomethine ylides under mild conditions.

Single electron transfer-mediated photochemical reaction of C60 fullerene with simple bis-α-silyl tertiary alkyl/benzyl amines has been developed for the straightforward and valuable construction of dumbbell-like single-bonded bis aminomethyl-1, 2-dihydrofullerenes under milder condition. In these studies of photoinduced SET reactions, α-amino radicals serve as the reactive key intermediate, which was selectively obtained by using the bis-α-silyl tertiary alkyl amines as starting materials. The present strategy was compatible with various 2, 2′-oxybis (ethane-2, 1-diyl) bis (2-(alkyl/benzyl-substituted ((trimethylsilyl) methyl) amino) acetate) for the synthesis of bis aminomethyl-1, 2-dihydrofullerenes under a photocatalyst-free condition.

In recent years, crystalline polyoxotitanium clusters (PTCs) have attracted increasing attention as a new kind of promising crystalline material. In this work, a PTC stabilized by phenylphosphonate ligands, i.e. hexa-μ-isopropanolato-hexaisopropanolatodi-μ3-oxido-hexa-μ3-phenylphosphonato-heptatitanium tetrahydrate, [Ti7(μ3-O)2(O3P-Phen)6(OiPr)12]·4H2O [PTC-54; H2O3P-Phen is phenylphosphonic acid, C6H5PO(OH)2, and HOiPr is isopropanol, C3H7OH], was obtained successfully through a facile one-step solvothermal reaction. The dumbbell-like core structure of PTC-54 can be described as two trinuclear {Ti3(μ3-O)} building units combined together by six phenylphosphonate ligands and one additional Ti atom, giving rise to a Ti7 cluster. Adjacent molecules of PTC-54 are further connected through π–π interactions between the phenyl groups to form a supramolecular one-dimensional chain.

Four BTD-derivatives 4 , 5 , 7 and 8 were synthesized and characterized by using solution NMR, FTIR and HRMS. In this study, BTD-central cores were supported on trityl type fragments in order to evaluate the influence of these groups prone to aggregation through interdigitation in the consolidation of ordered solids. Structural variation, between compounds 4–5 and 7–8, was selected by introducing aromatic phenyl rings at positions C-4 and C-7 of the BTD central core in order to increase the stackable surface. Crystals of compounds 4 and 5 were obtained and solved in the C 2/ c and P 2 1 / c space groups, respectively. Both crystalline arrays are dominated by C H⋯π and π-stacking interactions, desirable features for the bottom-up construction of highly polarizable organic crystals. The featured compounds with a dumbbell-like structure could be useful as scaffolds for self-assembled crystalline materials such as solid organic semiconductors.

Dumbbell-like Au-Fe3O4 nanoparticles are emerging as attractive nanocatalysts in recent years. However, they still suffer from the instability related activity attenuation. Herein, dumbbell-like Au-Fe3O4 nanoparticles encapsulated in N-doped carbon shell (Au-Fe3O4@Carbon) as novel yolk@shell nanocatalysts were synthesized via template assisted method, with which the yolk@shell scaffolds and even the diameter of the hollow space is totally designable. The yolk@shell structured Au-Fe3O4@Carbon was demonstrated to exhibit high stability and enhanced activity towards the reduction of 4-nitrophenol. Moreover, 100% yield was determined for the benzhydrol oxidation reaction taking advantage of the as prepared Au-Fe3O4@Carbon yolk@shell nanocatalysts. Furthermore, the Au-Fe3O4@Carbon nanocatalysts presented herein exhibit superior recyclability, which laid the foundation for its practical application. The mechanism for the enhanced catalytic behavior were clearly addressed. It is anticipated that the elaborate design of this work can lead to the exploration of novel nanocatalysts with superior catalytic performance.

Development of high performance room temperature sensors remains a grand challenge for high demand of practical application. Metal oxide semiconductors (MOSs) have many advantages over others due to their easy functionalization, high surface area, and low cost. However, they typically need a high work temperature during sensing process. Here, p-type sensing layer is reported, consisting of pore-rich dumbbell-like Co3O4 particles (DP-Co3O4) with intrinsic high catalytic activity. The gas sensor (GS) based DP-Co3O4 catalyst exhibits ultrahigh NH3 sensing activity along with excellent stability over other structure based NH3 GSs in room temperature work environment. In addition, the unique structure of DP-Co3O4 with pore-rich and high catalytic activity endows fast gas diffusion rate and high sensitivity at room temperature. Taken together, the findings in this work highlight the merit of integrating highly active materials in p-type materials, offering a framework to develop high-sensitivity room temperature sensing platforms.

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–Fe3O4–MnOx and dendritic Pt–MnOx 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–MnOx NPs were synthesized through the assembly of small seed NPs. On the other hand, dumbbell-like Pt–Fe3O4–MnOx 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–Fe3O4–MnOx 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.

Hierarchical β -NaGdF 4 nanobundles are synthesized through a facile hydrothermal method with the use of sodium acetate (NaAc). A NaGdF 4 -GdF 3 -NaGdF 4 products transformation with the increase of fluoride source (NaF) is observed. Results show that NaAc is the key factor in the synthesis of β -NaGdF 4 at a low NaF/Gd 3+ ratio and NaAc also plays a significant role in the formation of the hierarchical morphology. Meanwhile, the size of nanobundles increases with the increased ratio of NaF/NaAc. With altering the ratio of reactants, dumbbell-like, urchin-like or rod-like β -NaGdF 4 nanobundles are obtained. The photoluminescent properties of β -NaGdF 4 : 2%Eu 3+ are also measured.

Gaseous diffusion of n-hexane into the reaction mixture of sodium dicyanamide NaN(CN)2 with 15-crown-5 in tetrahydrofuran leads to a sodium dicyanamide compound [Na(15-crown-5)]N(CN)2 (1). Compound 1 exhibits a centrosymmetric dumbbell-like structure constructed by dicyanamide ligands double-bridging [Na(15-crown-5)]+ moieties with a μ-1,5 coordination mode. Solid-state photoluminescence experiments have shown that compound 1 emits violet luminescence, and its possible emission mechanism was investigated in detail based on theoretical calculations.

We synthesize dumbbell-like FePt–Fe3O4 nanoparticles (NPs) and study their electrocatalytic oxidation and sensing of dopamine (DA). The FePt and Fe3O4 NPs are strongly coupled in the dumbbell structure and as a result, the dumbbell FePt–Fe3O4 NPs show the best activity for DA oxidation with the DA detection limit reaching 1 nM. They are used successfully to monitor the DA concentration increase induced by K+-stimulation of PC12 cells. Our data show that an electrode modified with dumbbell-like FePt–Fe3O4 NPs can serve as the most sensitive probe for real-time quantitative detection of DA in a neurological environment.

Au@FeOx dumbbell nanocrystals (NCs) with different sizes of the Au domain (i.e. 4 nm, 6 nm and 10 nm) were successfully synthesized by means of a colloidal synthesis procedure. They were then deposited on γ-alumina and tested in CO oxidation. The use of alumina minimized the contribution of the Au-support interaction in the CO oxidation, thus enabling us to clearly identify a synergy between the Au and the iron oxide that eventually resulted in an enhanced activity in CO oxidation, good sintering resistance and good stability of the catalytic performances. Among the three gold sizes tested, the dumbbells with 4 nm Au domains were found to be the most active ones. Nevertheless, we found that the activity of the 4 nm dumbbells was significantly hampered by the limited exposure of the Au or of the Au/iron oxide interface to the reacting environment.

This paper reviews several important factors that influence the synthesis of dumbbell-like nanoparticles, which can significantly enhance the catalyst activity in catalytic combustion. The dumbbell-like nanoparticles discussed in this article refer to a hetero-structure with two nanoparticles of different materials in contact with each other. This nanostructure can be considered as a special intermediate between individual spherical nanoparticles and a core–shell nanostructure. Therefore, the synthesis of dumbbell-like nanoparticles is more difficult than other structures. The controllability of the synthesis process, the nanoparticle size and size distribution, and the morphology of the final products depend on many factors: the seed size and size ratio could be used to influence the controllability of epitaxial growth. The component sizes and size distribution could be varied by carefully controlling the reaction temperature and reaction time. The morphology of the dumbbell-like nanoparticles is closely related to the solvent polarity, the precursor ratio, the lattice mismatch between the two components, and the surfactant concentration. Some related synthesis methods are also briefly introduced in each section to facilitate understanding. This summary will benefit the development of new dumbbell-like nanoparticles with various components, which have great potential in catalytic combustion of more dysoxidizable gases.

The first one-step synthesis of dumbbell-like gold–iron oxide nanoparticles has been reported here. Surface functionalization with a biocompatible chitosan matrix allowed us to obtain a novel targetable diagnostic and therapeutic tool.

Novel kinetic models for both Dumbbell-like and rigid-rod like polymers are derived, based on the probability distribution function $f(t, x, n, \dot n)$ for a polymer molecule positioned at $x$ to be oriented along direction $n$ while embedded in a $\dot n$ environment created by inertial effects. It is shown that the probability distribution function of the extended model, when converging, will lead to well accepted kinetic models when inertial effects are ignored such as the Doi models for rod like polymers, and the Finitely Extensible Non-linear Elastic (FENE) models for Dumbbell like polymers., 23 pages, 2 figures