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An efficient CuPd nanoparticle (NP) catalyst (3 nm CuPd NPs deposited on carbon support) is designed for catalyzing electrochemical allylic alkylation in water/isopropanol (1:1 v/v) and 0.2 m KHCO 3 solution at room temperature. The Pd catalysis was Pd/Cu composition-dependent, and CuPd NPs with a Pd/Cu ratio close to one are the most efficient catalyst for the selective cross-coupling of alkyl halides and allylic halides to form C-C hydrocarbons with product yields reaching up to 99 %. This NP-catalyzed electrochemical allylic alkylation expands the synthetic scope of cross-coupling reactions and can be further extended to other organic reaction systems for developing green chemistry electrosynthesis methods., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Permanent magnets are a class of critical materials for information storage, energy storage, and other magneto-electronic applications. Compared with conventional bulk magnets, magnetic nanoparticles (MNPs) show unique size-dependent magnetic properties, which make it possible to control and optimize their magnetic performance for specific applications. The synthesis of MNPs has been intensively explored in recent years. Among different methods developed thus far, chemical synthesis based on solution-phase reactions has attracted much attention owing to its potential to achieve the desired size, morphology, structure, and magnetic controls. This Minireview focuses on the recent chemical syntheses of strongly ferromagnetic MNPs (H c >10 kOe) of rare-earth metals and FePt intermetallic alloys. It further discusses the potential of enhancing the magnetic performance of MNP composites by assembly of hard and soft MNPs into exchange-coupled nanocomposites. High-performance nanocomposites are key to fabricating super-strong permanent magnets for magnetic, electronic, and energy applications., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We report a flame-reaction method to synthesize high-performance Sm x Co y (x=1, y=5; x=2, y=17) particles on a multigram scale. This flame reaction allows the controlled decomposition of Sm(NO 3 ) 3 and Co(NO 3 ) 2 to 320 nm SmCo-O (SmCoO 3 + Co 3 O 4 ) particles. A 5.8 g sample of SmCo 3.8 -O particles was coated with CaO and then reduced at 900 °C by Ca to give 4.2 g of 260 nm SmCo 5 particles. The SmCo 5 particles are strongly ferromagnetic and the aligned particles in epoxy resin exhibit a large room-temperature coercivity (H c ) of 41.8 kOe and giant (BH) max (maximum magnetic energy product) of 19.6 MGOe, the highest value ever reported for SmCo 5 made by chemical methods. This synthesis can be extended to synthesize Sm 2 Co 17 particles, providing a general approach to scaling up the synthesis of high-performance Sm x Co y nanomagnets for permanent magnet applications., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We report a new strategy to prepare a composite catalyst for highly efficient electrochemical CO 2 reduction reaction (CO 2 RR). The composite catalyst is made by anchoring Au nanoparticles on Cu nanowires via 4,4'-bipyridine (bipy). The Au-bipy-Cu composite catalyzes the CO 2 RR in 0.1 m KHCO 3 with a total Faradaic efficiency (FE) reaching 90.6 % at -0.9 V to provide C-products, among which CH 3 CHO (25 % FE) dominates the liquid product (HCOO - , CH 3 CHO, and CH 3 COO - ) distribution (75 %). The enhanced CO 2 RR catalysis demonstrated by Au-bipy-Cu originates from its synergistic Au (CO 2 to CO) and Cu (CO to C-products) catalysis which is further promoted by bipy. The Au-bipy-Cu composite represents a new catalyst system for effective CO 2 RR conversion to C-products., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Efficient electro-oxidation of formic acid, methanol, and ethanol is challenging owing to the multiple chemical reaction steps required to accomplish full oxidation to CO 2 . Herein, a ternary CoPtAu nanoparticle catalyst system is reported in which Co and Pt form an intermetallic L1 0 -structure and Au segregates on the surface to alloy with Pt. The L1 0 -structure stabilizes Co and significantly enhances the catalysis of the PtAu surface towards electro-oxidation of ethanol, methanol, and formic acid, with mass activities of 1.55 A/mg Pt , 1.49 A/mg Pt , and 11.97 A/mg Pt , respectively in 0.1 m HClO 4 . The L1 0 -CoPtAu catalyst is also stable, with negligible degradation in mass activities and no obvious Co/Pt/Au composition changes after 10 000 potential cycles. The in situ surface-enhanced infrared absorption spectroscopy study indicates that the ternary catalyst activates the C-C bond more efficiently for ethanol oxidation., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We report a general chemical approach to synthesize strongly ferromagnetic rare-earth metal (REM) based SmCo and SmFeN nanoparticles (NPs) with ultra-large coercivity. The synthesis started with the preparation of hexagonal CoO+Sm 2 O 3 (denoted as SmCo-O) multipods via decomposition of Sm(acac) 3 and Co(acac) 3 in oleylamine. These multipods were further reduced with Ca at 850 °C to form SmCo 5 NPs with sizes tunable from 50 to 200 nm. The 200 nm SmCo 5 NPs were dispersed in ethanol, and magnetically aligned in polyethylene glycol (PEG) matrix, yielding a PEG-SmCo 5 NP composite with the room temperature coercivity (H c ) of 49.2 kOe, the largest H c among all ferromagnetic NPs ever reported, and saturated magnetic moment (M s ) of 88.7 emu g -1 , the highest value reported for SmCo 5 NPs. The method was extended to synthesize other ferromagnetic NPs of Sm 2 Co 17 , and, for the first time, of Sm 2 Fe 17 N 3 NPs with H c over 15 kOe and M s reaching 127.9 emu g -1 . These REM based NPs are important magnetic building blocks for fabrication of high-performance permanent magnets, flexible magnets, and printable magnetic inks for energy and sensing applications., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Ni 30 Pd 70 nanoparticles supported on nitrogen-doped graphene (NG) acts as a catalyst for the hydrodehalogenation of halogenated aromatics under mild reaction conditions. It reduces mono- or dichloroarenes to the corresponding dehalogenated arenes in >90 % yield in 10 % aqueous isopropanol solvent at or below 50 °C within 5 h. Tests on a variety of substrates containing various functional groups show that the catalyst is selective for reduction of C-Cl and C-Br bonds. In addition, this catalyst completely hydrodehalogenates high-concentration solutions of dioxin, polychlorinated biphenyls, chloroaromatic constituents of the defoliant agent orange, and polybrominated diphenyl ethers in 12 h. The catalyst is reusable and shows no morphological or compositional changes after 5 cycles. This methodology offers a powerful, low-cost, and safe technology for the degradation of polyhalogenated aromatics, and may be useful for preventing proliferation of these toxins in the environment from causing serious health issues., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We report a facile method for assembly of a monolayer array of nitrogen-doped graphene (NG) and nanoparticles (NPs) and the subsequent transfer of two layers onto a solid substrate (S). Using 3 nm NiPd NPs as an example, we demonstrate that NiPd-NG-Si (Si=silicon wafer) can function as a catalyst and show maximum NiPd catalysis for the hydrolysis of ammonia borane (H 3 NBH 3 , AB) with a turnover frequency (TOF) of 4896.8 h -1 and an activation energy (E a ) of 18.8 kJ mol -1 . The NiPd-NG-S catalyst is also highly active for catalyzing the transfer hydrogenation from AB to nitro compounds, leading to the green synthesis of quinazolines in water. Our assembly method can be extended to other graphene and NP catalyst materials, providing a new 2D NP catalyst platform for catalyzing multiple reactions in one pot with maximum efficiency., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A facile approach to bimetallic phosphides, Co-Fe-P, by a high-temperature (300 °C) reaction between Co-Fe-O nanoparticles and trioctylphosphine is presented. The growth of Co-Fe-P from the Co-Fe-O is anisotropic. As a result, Co-Fe-P nanorods (from the polyhedral Co-Fe-O nanoparticles) and sea-urchin-like Co-Fe-P (from the cubic Co-Fe-O nanoparticles) are synthesized with both the nanorod and the sea-urchin-arm dimensions controlled by Co/Fe ratios. The Co-Fe-P structure, especially the sea-urchin-like (Co(0.54)Fe(0.46))2P, shows enhanced catalysis for the oxygen evolution reaction in KOH with its catalytic efficiency surpassing the commercial Ir catalyst. Our synthesis is simple and may be readily extended to the preparation of other multimetallic phosphides for important catalysis and energy storage applications., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Monodisperse core/shell FeNiPt/FePt nanowires (4.5 × 20-50 nm) are synthesized by seed-mediated growth of FePt over the pre-made 2.5 nm wide FeNiPt nanowires. The surface profile of the FeNiPt/FePt nanowires is tailored by acid and thermal treatment. The FeNiPt/Pt-skin nanowires show higher activities than the FeNiPt/Pt-skeleton nanowires., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Monodisperse 5 nm AuMn nanoparticles were synthesized by hydride reduction of manganese acetylacetonate in the presence of Au nanoparticles. The alloy was formed through fast Mn diffusion into the Au structure. The AuMn nanoparticles were converted to Au-MnO composite particles through air annealing at 170 °C. These Au-MnO particles, especially the core/shell Au/MnO nanoparticles, were active for the electrochemical reduction of H2 O2 , with a detection limit reaching 8 nM. This highly sensitive electrochemical sensor based on the Au/MnO nanoparticles was used to monitor H2 O2 concentrations released from living cells, from which tumorigenic cells were discovered to release higher levels of H2 O2 than the non-tumorigenic cells., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Controlling exchange coupling between hard magnetic and soft magnetic phases is the key to the fabrication of advanced magnets with tunable magnetism and high energy density. Using FePt as an example, control over the magnetism in exchange-coupled nanocomposites of hard magnetic face-centered tetragonal (fct) FePt and soft magnetic Co (or Ni, Fe2C) is shown. The dispersible hard magnetic fct-FePt nanoparticles are first prepared with their coercivity (Hc) reaching 33 kOe. Then core/shell fct-FePt/Co (or Ni, Fe2C) nanoparticles are synthesized by reductive thermal decomposition of the proper metal precursors in the presence of fct-FePt nanoparticles. These core/shell nanoparticles are strongly coupled by exchange interactions and their magnetic properties can be rationally tuned by the shell thickness of the soft phase. This work provides an ideal model system for the study of exchange coupling at the nanoscale, which will be essential for building superstrong magnets for various permanent magnet applications in the future., (Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Advances in chemical syntheses have led to the formation of various kinds of nanoparticles (NPs) with more rational control of size, shape, composition, structure and catalysis. This review highlights recent efforts in the development of Pt and non-Pt based NPs into advanced nanocatalysts for efficient oxygen reduction reaction (ORR) under fuel-cell reaction conditions. It first outlines the shape controlled synthesis of Pt NPs and their shape-dependent ORR. Then it summarizes the studies of alloy and core-shell NPs with controlled electronic (alloying) and strain (geometric) effects for tuning ORR catalysis. It further provides a brief overview of ORR catalytic enhancement with Pt-based NPs supported on graphene and coated with an ionic liquid. The review finally introduces some non-Pt NPs as a new generation of catalysts for ORR. The reported new syntheses with NP parameter-tuning capability should pave the way for future development of highly efficient catalysts for applications in fuel cells, metal-air batteries, and even in other important chemical reactions., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A simple process to prepare monodisperse ferrimagnetic cobalt-substituted magnetite Co(x)Fe(3-x)O4 nanoparticles is reported. These ferrimagnetic nanoparticles are readily dispersed in hexane, forming a stable ferrimagnetic nanoparticle dispersion, and allowing easy nanoparticle self-assembly. When assembled under an external magnetic field (5.5 kOe), these nanoparticles show preferred magnetic alignment with their H(c) reaching 2.49 kOe., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Dumbbell-like Pt(48)Pd(52)-Fe(3)O(4) nanoparticles are synthesized and functionalized with oleylamine-polyethyleneglycol to serve as an efficient catalyst for H(2)O(2) reduction and tetramethylbenzidine (TMB) oxidation in biological solutions. The Pt(48)Pd(52)-Fe(3)O(4)/TMB kit is even more active than the natural enzyme for H(2)O(2) detection with a detection limit reaching 2 μM, and is successfully used to quantitatively monitor the extracellular H(2)O(2) generated by neutrophils., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Transition-metal phosphide nanowires were facilely synthesized by Ullmann-type reactions between transition metals and triphenylphosphine in vacuum-sealed tubes at 350-400 degrees C. The phase (stoichiometry) of the phosphide products is controllable by tuning the metal/PPh(3) molar ratio and concentration, reaction temperature and time, and heating rate. Six classes of iron, cobalt, and nickel phosphide (Fe(2)P, FeP, Co(2)P, CoP, Ni(2)P, and NiP(2)) nanostructures were prepared to demonstrate the general applicability of this new method. The resulting phosphide nanostructures exhibit interesting phase- and composition-dependent magnetic properties, and magnetic measurements suggested that the Co(2)P nanowires with anti-PbCl(2) structure show a ferromagnetic-paramagnetic transition at 6 K, while the MnP-structured CoP nanowires are paramagnetic with Curie-Weiss behavior. Moreover, GC-MS analyses of organic byproducts of the reaction revealed that thermally generated phenyl radicals promoted the formation of transition-metal phosphides under synthetic conditions. Our work offers a general method for preparing one-dimensional nanoscale transition-metal phosphides that are promising for magnetic and electronic applications.

Synthesis of multifunctional magnetic nanoparticles (MFMNPs) is one of the most active research areas in advanced materials. MFMNPs that have magnetic properties and other functionalities have been demonstrated to show great promise as multimodality imaging probes. Their multifunctional surfaces also allow rational conjugations of biological and drug molecules,making it possible to achieve target-specific diagnostics and therapeutics.This review fi rst outlines the synthesis of MNPs of metal oxides and alloy sand then focuses on recent developments in the fabrication of MFMNPs of core/shell, dumbbell, and composite hybrid type. It also summarizes the general strategies applied for NP surface functionalization. The review further highlights some exciting examples of these MFMNPs for multimodality imaging and for target-specific drug/gene delivery applications.

Au nanowires have attracted significant interest in nanomaterials research owing to their chemical stability and high conductivity for potential nanoelectronic applications. However, previous syntheses yielded only polycrystalline Au nanowires with diameters larger than 10 nm. Very recent advances in solution-phase synthesis have led to the formation of ultrathin single-crystalline Au nanowires with diameters of less than 10 nm. This Focus Review summarizes the synthesis, characterization, and transport studies of these ultrathin single-crystalline Au nanowires for potential electronic device applications.

Surface-modified Fe(3)O(4) nanoparticles (NPs) can be obtained by substituting [(eta(5)-semiquinone)Mn(CO)(3)] for oleylamine surface protecting groups. The resulting NP can function as a nucleus or template to generate crystalline coordination polymers that contain superparamagnetic Fe(3)O(4) NPs. Hybridized magnetic properties can be obtained by introducing paramagnetic metal nodes, such as Mn(2+), into the polymers (see picture).

This paper reviews the recent research progress in syntheses and applications of dumbbell-like nanoparticles. It first describes the general synthesis of dumbbell-like nanoparticles containing noble metal and magnetic NPs/or quantum dots. It then outlines the interesting optical and magnetic properties found in these dumbbell nanoparticles. The review further highlights several exciting application potentials of these nanoparticles in catalysis and biomedicine.

Functionalization of monodisperse superparamagnetic magnetite (Fe(3)O(4)) nanoparticles for cell specific targeting is crucial for cancer diagnostics and therapeutics. Targeted magnetic nanoparticles can be used to enhance the tissue contrast in magnetic resonance imaging (MRI), to improve the efficiency in anticancer drug delivery, and to eliminate tumor cells by magnetic fluid hyperthermia. Herein we report the nucleus-targeting Fe(3)O(4) nanoparticles functionalized with protein and nuclear localization signal (NLS) peptide. These NLS-coated nanoparticles were introduced into the HeLa cell cytoplasm and nucleus, where the particles were monodispersed and non-aggregated. The success of labeling was examined and identified by fluorescence microscopy and MRI. The work demonstrates that monodisperse magnetic nanoparticles can be readily functionalized and stabilized for potential diagnostic and therapeutic applications.