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Colloidal hybrid nanoparticles contain multiple nanoscale domains fused together by solid-state interfaces. They represent an emerging class of multifunctional lab-on-a-particle architectures that underpin future advances in solar energy conversion, fuel-cell catalysis, medical imaging and therapy, and electronics. The complexity of these 'artificial molecules' is limited ultimately by the lack of a mechanism-driven design framework. Here, we show that known chemical reactions can be applied in a predictable and stepwise manner to build complex hybrid nanoparticle architectures that include M-Pt-Fe(3)O(4) (M = Au, Ag, Ni, Pd) heterotrimers, M(x)S-Au-Pt-Fe(3)O(4) (M = Pb, Cu) heterotetramers and higher-order oligomers based on the heterotrimeric Au-Pt-Fe(3)O(4) building block. This synthetic framework conceptually mimics the total-synthesis approach used by chemists to construct complex organic molecules. The reaction toolkit applies solid-state nanoparticle analogues of chemoselective reactions, regiospecificity, coupling reactions and molecular substituent effects to the construction of exceptionally complex hybrid nanoparticle oligomers.

Nanoscale transition metal tellurides are important materials for a variety of applications. However, solution‐phase methods to synthesize nanoscale transition metal tellurides are not as well‐developed as for related sulfide and selenide systems. Here, we show that pre‐formed colloidal metal nanoparticles react with bis(trimethylsilyl)telluride to form their corresponding tellurides. Nanoparticles of Pd, Pt, and Ni convert to nanoscale particles of the layered transition metal dichalcogenides PdTe2, PtTe2, and NiTe2 upon reaction with bis(trimethylsilyl)telluride. When Pd nanoparticles instead react with a TOP‐Te complex (TOP = trioctylphosphine), PdTe forms. This result demonstrates that the metal telluride phase that forms can be controlled by the reactivity of the tellurium reagent. Other nanoparticles, including Co, Ag, and Rh, also form crystalline metal tellurides upon reaction with bis(trimethylsilyl)telluride, which indicates that this approach to synthesizing nanoscale transition metal tellurides is general. [ABSTRACT FROM AUTHOR]

New synthetic innovations are rapidly being developed to address the demand for complex, next-generation nanomaterials with rigorously controlled architectures and interfaces. This Review highlights key strategies for the chemical transformation and stepwise synthesis of multicomponent inorganic nanostructures, with the existing nanoscale transformations categorized into classes of reactions that are related to those used in the synthesis of organic molecules. The application of concepts used in molecular synthesis-including site-selectivity, regio- and chemoselectivity, orthogonal reactivity, coupling reactions, protection/deprotection strategies, and procedures for separation and purification-to nanoscale systems is emphasized. Collectively, the resulting synthetic concept represents an emerging model for the synthesis of complex inorganic nanostructures on the basis of the guiding principles that underpin the multistep total synthesis of complex organic molecules and natural products. [ABSTRACT FROM AUTHOR]

Colloidal hybrid nanoparticles contain multiple nanoscale domains fused together by solid-state interfaces. They represent an emerging class of multifunctional lab-on-a-particle architectures that underpin future advances in solar energy conversion, fuel-cell catalysis, medical imaging and therapy, and electronics. The complexity of these 'artificial molecules' is limited ultimately by the lack of a mechanism-driven design framework. Here, we show that known chemical reactions can be applied in a predictable and stepwise manner to build complex hybrid nanoparticle architectures that include M-Pt-Fe3O4 (M = Au, Ag, Ni, Pd) heterotrimers, MxS-Au-Pt-Fe3O4 (M = Pb, Cu) heterotetramers and higher-order oligomers based on the heterotrimeric Au-Pt-Fe3O4 building block. This synthetic framework conceptually mimics the total-synthesis approach used by chemists to construct complex organic molecules. The reaction toolkit applies solid-state nanoparticle analogues of chemoselective reactions, regiospecificity, coupling reactions and molecular substituent effects to the construction of exceptionally complex hybrid nanoparticle oligomers. [ABSTRACT FROM AUTHOR]

Amorphous tungsten phosphide (WP), which has been synthesized as colloidal nanoparticles with an average diameter of 3 nm, has been identified as a new electrocatalyst for the hydrogen-evolution reaction (HER) in acidic aqueous solutions. WP/Ti electrodes produced current densities of -10 mA cm-2 and -20 mA cm-2 at overpotentials of only -120 mV and -140 mV, respectively, in 0.50 M H2SO4(aq). [ABSTRACT FROM AUTHOR]

Review: 91 refs. [ABSTRACT FROM AUTHOR]

Colloidal hybrid nanoparticles, whichcontain multiple inorganicdomains that are joined together through solid–solid interfaces,exhibit particle multifunctionality as well as new and enhanced propertiesthat can emerge from the particle–particle interactions. Thesehybrid nanoparticles are typically synthesized using heterogeneousseeded nucleation of one nanoparticle on the surface of another aswell as using phase segregation, surface dewetting of core–shellnanoparticles, and the fusion of premade nanoparticles. However, toexpand the materials diversity and the potential range of applicationsof such systems, alternative routes to heterogeneous seeded nucleationare needed. Here, we show that solution–liquid–solidand related supersaturation-precipitation strategies, traditionallyused in the synthesis of 1D structures such as nanowires and nanorods,can also be applied to the synthesis of colloidal hybrid nanoparticles.Specifically, we show that colloidal Au and Ag nanoparticles can serveas seeds for the growth of colloidal Au–Ge and Ag–Geheterodimers upon reaction with Ge(HMDS)2(Ge(II)bis(hexamethyldisilylamide))at ∼290 and ∼320 °C, respectively. By modifyingthe size of the seed nanoparticles and the amount of Ge(HMDS)2, the widths and lengths of the Ge domains can be systematicallytuned. Additionally, the Ge domains can serve as site-selective templatesfor the galvanic deposition of metal nanoparticles, forming trimericAu–Ge–(Ag)nnanostructures.This alternate route to colloidal hybrid nanoparticles facilitatesthe integration of previously inaccessible group IV elements, andit could open the door to the design and synthesis of a wide rangeof new functional colloidal nanostructures. [ABSTRACT FROM AUTHOR]

Colloidal hybrid nanoparticles integrate two or more nanocrystal domains into a single architecture that can have properties not found in, or enhanced relative to those of, the individual components. These hybrid nanomaterials are typically constructed using multistep seeded-growth reaction sequences, which are conceptually analogous to the total synthesis approaches used in molecular synthesis. Here, we discuss in detail the synthetic protocols that lead to the formation of three-component Ag-Pt-Fe3O4 and Au-Pt-Fe3O4 heterotrimers. These instructive model systems highlight the important synthetic details that underpin successful hybrid nanoparticle reactions. We provide detailed, step-by-step protocols for generating these materials, focusing on describing and rationalizing the key reaction parameters that need to be rigorously controlled to minimize unwanted nanoparticle byproducts. The importance of comprehensive analysis using a suite of materials characterization tools is highlighted, as such efforts are useful for diagnosing subtle chemical and morphological features that can lead to synthetic bottlenecks throughout the course of the reaction sequences. Finally, we offer strategies for circumventing these commonly encountered problems as well as insights that can lead to increased hybrid nanoparticle yields and improved sample-to-sample reproducibility. Although this work specifically details the synthesis of Ag-Pt-Fe3O4 and Au-Pt-Fe3O4 heterotrimers, these synthetic strategies and protocol guidelines are generally applicable to many other hybrid nanoparticle systems. [ABSTRACT FROM AUTHOR]

We report the colloidal synthesis of substrate-free MoSe2 nanostructures with a uniform flower-like morphology and tunable average diameters that range from approximately 50-250 nm. The MoSe2 nanoflowers contain a large population of highly crystalline few-layer nanosheets that protrude from a central core. Aliquot studies and control experiments indicate that the nanoflowers are generated through a two-step process that involves the formation of a core in the early stages of the reaction followed by outward nanosheet growth that can be controlled based on the concentrations of reagents. The effects of laser-induced local heating, bulkscale heating using a temperature stage, and nanostructuring on the ability to trigger and tune interlayer decoupling were also investigated. Notably, laser-induced local heating results in dynamic and reversible interlayer decoupling. Such capabilities provide a pathway for achieving quasi-two-dimensional behavior in three-dimensionally structured and colloidally synthesized transition metal dichalcogenide nanostructures. [ABSTRACT FROM AUTHOR]

Germanium telluride (GeTe) nanostructuresare a demonstrated platformfor studying the effects of scaling on reversible, amorphous-to-crystallinephase transitions that are important for data storage and computingapplications, and for understanding ferroelectric behavior at thenanometer scale. Despite the interest in GeTe, and the apparent advantagesof solution-phase processing, there is a dearth of information relatedto the synthesis of high-quality, morphology-controlled, colloidalGeTe. This paper describes the preparation of colloidal GeTe nanostructuresin the presence of surface-stabilizing polymers, which mediate particle–particleinteractions and prevent aggregation of GeTe crystallites more effectivelythan conventional molecular stabilizers. As a result, several novelGeTe nanostructures are formed, including faceted octahedral nanoparticles,amorphous GexTe1–xalloy nanospheres and single-crystal two-dimensional (2D)GeTe nanosheets. The colloidal stability conferred by the polymermay provide the key experimental degree of freedom necessary to achievehigher-order morphology control for GeTe and related materials. [ABSTRACT FROM AUTHOR]