Nanocrystals with metastable high-pressure phases under ambient conditions

Xiao, Tian-Yuan; Nagaoka, Yosuke; Wang, Xirui; Jiang, Tian; LaMontagne, Derek; Zhang, Qiang; Cao, Can; Diao, Xizheng; Qiu, Jiahua; Lu, Yiruo; Wang, Zhongwu; Cao, Y. Charles

doi:10.1126/science.abq7684

Cited by 32 publications

(26 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For another special example, Xiao et al found that suitable surface binding strength between amines and nanocrystals, as well as the ability of amine-capped nanocrystals to assemble into ordered superstructures, helped to retain the high pressure-induced metastable rock-salt (RS) phase of CdS (or CdSe) nanocrystals at ambient conditions. 26 For the CdS/CdSe nanocrystals capped with a mixture of oleylamine and cetyltrimethylammonium bromide, the pure RS phase obtained with compression could be fully preserved after decompression. As a typical kind of Cu-based semiconductor, Cu-based multicomponent semiconductor nanomaterials, such as Cu 2 ZnSnS 4 and Cu 2 ZnSn(S, Se) 4 , could crystallize in conventional tetragonal kesterite or stannite phases (in which all cations and anions are located separately in one fcc sublattice and stacked like the ZB structure), 27,28 and metastable hexagonal WZ phase.…”

Section: Typical Ligands For Phase Engineering Of Nanomaterialsmentioning

confidence: 95%

“…The amine ligands tended to adsorb on the surface of WZ-ZnS at lower temperatures and desorbed at higher temperatures, leading to the WZ-to-ZB phase transformation with increasing reaction temperature. For another special example, Xiao et al found that suitable surface binding strength between amines and nanocrystals, as well as the ability of amine-capped nanocrystals to assemble into ordered superstructures, helped to retain the high pressure-induced metastable rock-salt (RS) phase of CdS (or CdSe) nanocrystals at ambient conditions . For the CdS/CdSe nanocrystals capped with a mixture of oleylamine and cetyltrimethylammonium bromide, the pure RS phase obtained with compression could be fully preserved after decompression.…”

Section: Typical Ligands For Phase Engineering Of Nanomaterialsmentioning

confidence: 99%

See 1 more Smart Citation

Ligand-Assisted Phase Engineering of Nanomaterials

Yun

Huang

et al. 2023

Acc. Chem. Res.

View full text Add to dashboard Cite

Conspectus The synthesis of monodisperse colloidal nanomaterials with well-defined structures is important for both fundamental research and practical application. To achieve it, wet-chemical methods with the usage of various ligands have been extensively explored to finely control the structure of nanomaterials. During the synthesis, ligands cap the surface and thus modulate the size, shape, and stability of nanomaterials in solvents. Besides these widely investigated roles of ligands, it has been recently discovered that ligands can affect the phase of nanomaterials, i.e., their atomic arrangement, providing an effective strategy to realize the phase engineering of nanomaterials (PEN) by selecting appropriate ligands. Nanomaterials normally exist in the phases that are thermodynamically stable in their bulk states. Previous studies have shown that under high temperature or high pressure, nanomaterials can exist in unconventional phases which are unattainable in the bulks. Importantly, nanomaterials with unconventional phases exhibit unique properties and functions different from conventional-phase ones. Consequently, it is feasible to utilize the PEN to tune the physicochemical properties and application performance of nanomaterials. During wet-chemical synthesis, ligands binding to the surface of nanomaterials can modify their surface energy, which could significantly affect the Gibbs free energy of nanomaterials and thus determine the stability of different phases, making it possible to obtain nanomaterials with unconventional phases at mild reaction conditions. For instance, a series of Au nanomaterials with unconventional hexagonal phases have been prepared with the assistance of oleylamine. Therefore, the rational design and selection of different ligands and deep understanding of their effect on the phase of nanomaterials would significantly accelerate the development of PEN and the discovery of novel functional nanomaterials for diverse applications. In this Account, we briefly summarize the recent progress in ligand-assisted PEN, elaborating the important roles of different ligands in the direct synthesis of nanomaterials with unconventional crystal phases and amorphous phase as well as the phase transformation of nanomaterials. We first introduce the background of this research topic, highlighting the concept of PEN and why ligands can modulate the phase of nanomaterials. Then we discuss the usage of four kinds of ligands, i.e., amines, fatty acids, sulfur-containing ligands, and phosphorus-containing ligands, in phase engineering of different nanomaterials, especially metal, metal chalcogenide, and metal oxide nanomaterials. Finally, we provide our personal views of the challenges and future promising research directions in this exciting field.

show abstract

Section: Typical Ligands For Phase Engineering Of Nanomaterialsmentioning

confidence: 95%

Section: Typical Ligands For Phase Engineering Of Nanomaterialsmentioning

confidence: 99%

Ligand-Assisted Phase Engineering of Nanomaterials

Yun

Huang

et al. 2023

Acc. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…Indeed, ligand effects on NC self-assembly and pressureinduced sintering processes have been utilized by Xiao et al to control kinetic barriers in NC phase transitions and fully preserve metastable high-pressure phases under ambient conditions. 111 For a given composition, a material can exist in various crystalline phases of different structures and properties, only one of which is often the thermodynamically most stable under ambient conditions. Kinetically trapping those higher energy phases (i.e., increasing the activation energy barrier of phase transitions) can potentially lead to metastable materials with new properties for emerging applications.…”

Section: Ligand Effectsmentioning

confidence: 99%

Theoretical and Experimental Advances in High-Pressure Behaviors of Nanoparticles

Meng,

Vu,

Criscenti

et al. 2023

Chem. Rev.

View full text Add to dashboard Cite

Using compressive mechanical forces, such as pressure, to induce crystallographic phase transitions and mesostructural changes while modulating material properties in nanoparticles (NPs) is a unique way to discover new phase behaviors, create novel nanostructures, and study emerging properties that are difficult to achieve under conventional conditions. In recent decades, NPs of a plethora of chemical compositions, sizes, shapes, surface ligands, and self-assembled mesostructures have been studied under pressure by in-situ scattering and/or spectroscopy techniques. As a result, the fundamental knowledge of pressure–structure–property relationships has been significantly improved, leading to a better understanding of the design guidelines for nanomaterial synthesis. In the present review, we discuss experimental progress in NP high-pressure research conducted primarily over roughly the past four years on semiconductor NPs, metal and metal oxide NPs, and perovskite NPs. We focus on the pressure-induced behaviors of NPs at both the atomic- and mesoscales, inorganic NP property changes upon compression, and the structural and property transitions of perovskite NPs under pressure. We further discuss in depth progress on molecular modeling, including simulations of ligand behavior, phase-change chalcogenides, layered transition metal dichalcogenides, boron nitride, and inorganic and hybrid organic–inorganic perovskites NPs. These models now provide both mechanistic explanations of experimental observations and predictive guidelines for future experimental design. We conclude with a summary and our insights on future directions for exploration of nanomaterial phase transition, coupling, growth, and nanoelectronic and photonic properties.

show abstract

“…Colloidal nanocrystals (NCs), which serve as designable atoms, can spontaneously self-assemble into periodically ordered superlattices. − Such superlattice solids, called “designer solids”, represent completely the new category of condensed matters, which not only can be used to explore the newly emergent properties at mesoscale , but also can be engineered into higher hierarchical materials. − Upon discovery of collective properties from a variety of NC assembles, recent pressure engineering of such NC-ordering supercrystals has enabled 100% retention of high pressure metastable phases at ambient conditions . Such single NC supercrystals also display noticeable anisotropy of collective property as superlattices change in space symmetry and crystallographic orientation. − In order to make better use of such unique properties and further enable fine-tuning and controllable engineering of such supercrystals, it is crucial to explore and find ways of designable control of NC assembly environments to grow large free-standing 3D single supercrystals with desired superlattices.…”

Section: Introductionmentioning

confidence: 99%

“…6−9 Upon discovery of collective properties from a variety of NC assembles, recent pressure engineering of such NC-ordering supercrystals has enabled 100% retention of high pressure metastable phases at ambient conditions. 10 Such single NC supercrystals also display noticeable anisotropy of collective property as superlattices change in space symmetry and crystallographic orientation. 11−14 In order to make better use of such unique properties and further enable fine-tuning and controllable engineering of such supercrystals, it is crucial to explore and find ways of designable control of NC assembly environments to grow large free-standing 3D single supercrystals with desired superlattices.…”

Section: ■ Introductionmentioning

confidence: 99%

Diffusion-Mediated Nucleation and Growth of fcc and bcc Nanocrystal Superlattices with Designable Assembly of Freestanding 3D Supercrystals

et al. 2023

Self Cite

View full text Add to dashboard Cite

Diffusion-mediated assembly of octahedral PbS nanocrystals (NCs) in a confined antisolvent environment displays a primary burst nucleation and Ostwald ripening growth of rhombic bcc supercrystals, followed by a secondary seed-based nucleation and oriented attachment growth of triangle fcc supercrystals. As the diffusion proceeds from ethanol across a sharp interface into NC-suspended toluene, a burst nucleation of supercrystal seeds occurs, and such supercrystals are quickly developed into rhombic grains that have a bcc structure. At a critical size of 10 μm, an Ostwald ripening event appears to guide the supercrystal growth. Upon grain growth above 30 μm, the fcc supercrystals start a nucleation at two symmetrical tips of individual rhombic crystals. Such fcc supercrystals are developed with a triangle shape, and two triangles are combined with one bcc rhombus in-between to form a butterfly-like bowtie stacking structure. The fcc triangle wings grow larger at a reduction of bcc rhombus cores. As the bcc cores gradually fade, such butterfly-like bowtie crystals aggregate and undergo an oriented attachment process, leading to the formation of freestanding 3D triangle crystals that have a single fcc lattice. Analysis of experimental observations and defined diffusion parameters reveals that fast solvent diffusion and high-NC concentration promote the growth of rhombic bcc supercrystals, while slow solvent diffusion and low-NC concentration accelerate the development of triangle fcc supercrystals. Upon succeeding in designable growth of 3D fcc supercrystals, this study provides designing principles for controlled fabrication of supercrystals with desired superlattices for additional engineering and applications.

show abstract

Nanocrystals with metastable high-pressure phases under ambient conditions

Cited by 32 publications

References 49 publications

Ligand-Assisted Phase Engineering of Nanomaterials

Ligand-Assisted Phase Engineering of Nanomaterials

Theoretical and Experimental Advances in High-Pressure Behaviors of Nanoparticles

Diffusion-Mediated Nucleation and Growth of fcc and bcc Nanocrystal Superlattices with Designable Assembly of Freestanding 3D Supercrystals

Contact Info

Product

Resources

About