Growth Interface Research Articles

Interfacial Engineering of Heterogeneous Reactions for MOF-on-MOF Heterostructures.

Metal-organic frameworks (MOFs), as a subclass of porous crystalline materials with unique structures and multifunctional properties, play a pivotal role in various research domains. In recent years, significant attention has been directed toward composite materials based on MOFs, particularly MOF-on-MOF heterostructures. Compared to individual MOF materials, MOF-on-MOF structures harness the distinctive attributes of two or more different MOFs, enabling synergistic effects and allowing for the tailored design of diverse multilayered architectures to expand their application scope. However, the rational design and facile synthesis of MOF-on-MOF composite materials are in principle challenging due to the structural diversity and the intricate interfaces. Hence, this review primarily focuses on elucidating the factors that influence their interfacial growth, with a specific emphasis on the interfacial engineering of heterogeneous reactions, in which MOF-on-MOF hybrids can be conveniently obtained by using pre-fabricated MOF precursors. These factors are categorized as internal and external elements, encompassing inorganic metals, organic ligands, lattice matching, nucleation kinetics, thermodynamics, etc. Meanwhile, these intriguing MOF-on-MOF materials offer a wide range of advantages in various application fields, such as adsorption, separation, catalysis, and energy-related applications. Finally, this review highlights current complexities and challenges while providing a forward-looking perspective on future research directions.

A Tailored Interface Design for Anode-Free Solid-State Batteries.

Anode-free solid-state batteries (AFSSBs) are considered to be one of the most promising high-safety and high-energy storage systems. However, low Coulombic efficiency stemming from severe deterioration on solid electrolyte/current collector (Cu foil) interface and undesirable Li dendrite growth impede their practical application, especially when rigid garnet electrolyte is used. Here, an interfacial engineering strategy between garnet electrolyte and Cu foil is introduced for stable and highly efficient AFSSBs. By utilizing the high Li ion conductivity of LiC6 layer, interfacial self-adaption ability arising from ductile lithiated polyacrylic acid polymer layer and regulated Li deposition via Li-Ag alloying reaction, the garnet-based AFSSB delivers a stable long-term operation. Additionally, when combined with a commercial LiCoO2 cathode (3.1mAhcm-2 ), the cell also exhibits an outstanding capacity retention due to the tailored interface design. The strategies for novel AFSSBs architecture thus offer an alternative route to design next-generation batteries with high safety and high density.

Ternary eutectic electrolytes attune the electrode/electrolyte interphase layer toward long-life zinc ion batteries

Eutectic electrolytes show promise for zinc-ion batteries due to their cost-effectiveness and eco-friendliness. However, the design of eutectic electrolytes is challenging due to their high viscosity, low solute solubility, and interface compatibility issues. A novel ternary eutectic electrolyte composed of choline chloride, ethylene glycol, urea and ZnCl2 is proposed in the study, and the complex interactions and compatibility between these components, and the interface growth principles were revealed systematically through experiments and theoretic simulations. Our research demonstrates the well-designed eutectic electrolyte can integrate optimific solvent-shell structure, favorable electrolyte interface as well as low viscosity perfectly, and can thus improve zinc plating kinetics and suppress dendrite growth, resulting in a durable, dendrite-free zinc electrode lasting over 3000 h. Moreover, Zn||CEU1Zn||PANI full cells also surprisingly achieved over 90 % retention rate after 8000 cycles at a relatively high current density of 2A·g−1. This multi-component eutectic electrolyte presents a promising solution for long-lasting metal-ion battery electrolytes.

Interfacial growth morphologies in dense eutectic crystal mushes

Abstract We consider the interfacial growth morphologies of crystals growing in contact in crystal mushes, with a specific application to those formed by the solidification of basaltic magma. We focus on the particular case of an augite (pyroxene) crystal growing between two plagioclase crystals. The augite is treated as an equant unfaceted crystal, whereas the plagioclase is faceted, and our treatment applies generally to such combinations. The resulting three-grain junctions in natural rock samples are commonly of two distinct types. In one, the two augite–plagioclase interfaces grow towards each other with opposite curvatures, whereas in the second the curvatures of the interfaces have the same sign, giving a distinctive morphology which we have called an eagle’s beak. This paper provides a theoretical framework to provide explanations for both of these morphologies, based on the kinetics of interfacial growth.

Directional Electrosynthesis of Adipic Acid and Cyclohexanone by Controlling the Active Sites on NiOOH.

Dicarboxylic acids and cyclic ketones, such as adipic acid (AA) and cyclohexanone (CHN), are essential compounds for the chemical industry. Although their production by electrosynthesis using electricity is considered one of the most promising strategies, the application of such processes has been hampered by a lack of efficient catalysts as well as a lack of understanding of the mechanism. Herein, a series of monolithic msig/ea-NiOOH-Ni(OH)2/NF were prepared by means of self-dissolution of metal matrix components, interface growth, and electrochemical activation (denoted as msig/ea). The as-synthesized catalysts have three-dimensional cuboid-like structures formed by interconnecting nanosheets composed of NiOOH. By theoretically guided regulation of the amounts of Ni3+ and oxygen vacancies (OV), a 96.5% yield of CHN from cyclohexanol (CHA) dehydrogenation and a 93.6% yield of AA from CHN oxidation were achieved. A combined experimental and theoretical study demonstrates that CHA dehydrogenation and CHN oxidation were promoted by the formation of Ni3+ and the peroxide species (*OOH) on OV. This work provides a promising approach for directional electrosynthesis of high-purity chemicals with in-depth mechanistic insights.

Synergistically regulating the separator pore structure and surface property toward dendrite-free and high-performance aqueous zinc-ion batteries

As an emerging electrochemical device, aqueous zinc-ion batteries (ZIBs) present promising potential in safe and large-scale energy storage. However, the large pores of commercial glass fiber (GF) separators result in uneven Zn2+ ion flux, leading to severe dendrite growth issues of Zn metal anodes. Herein, we integrated a multifunctional layer on the GF separator that can synergistically regulate the pore feature and surface property of commercial GF separators. Such modification layer, composed of nanocellulose and SiO2 nanoparticles, exhibited uniform nanoporous structure and abundant negatively charged polar functional groups. These features allow regulating the distribution of Zn2+ ions at the separator-anode interface, facilitating stable and uniform Zn nucleation and growth. Moreover, the electrostatic interaction between the negatively charged functional groups and Zn2+ ions enhanced the Zn2+ ion transport kinetics, preventing the Zn dendrites formation and adverse reactions. Consequently, the modified electrolyte-filled GF separator showed an increased Zn2+ ion transference number of 0.65. The symmetric Zn//Zn batteries utilizing such a separator achieved an impressive cycling life of 500 h at a high current density/capacity of 10 mA cm−2/4 mAh cm−2, nearly nine times longer than the battery using the unmodified GF separator (<55 h). The superior electrochemical performance was verified in both Zn//AC and Zn//LiMn2O4 full battery evaluations. This work presents a novel synergistic modification strategy for developing advanced separators for aqueous ZIBs.

Reliability improvement of SnAgCu interconnections under extreme temperature condition by TiO2 nanoparticles doping: Experiments and first principles calculations

Electronic components of the spacecraft during their service may endure intricate and extreme temperature environments. In this study, the interfacial microstructure evolution and reliability of Cu/Sn-3.0Ag-0.5Cu (SAC305)/Ni and Cu/Sn-3.0Ag-0.5Cu-0.05TiO2 (SAC305–0.05TiO2)/Ni interconnections under thermal shock from −196 °C to 150 °C are investigated. Short-column-type (Cu,Ni)6Sn5 intermetallic compounds (IMCs) are developed at the solder/Ni interface for both interconnections after the reflow process, and their morphology changes to long-rod type after 200 cycles. Extremely thin and discontinuous (Ni,Cu)3Sn4 phases are generated between (Cu,Ni)6Sn5 and Ni only in SAC305 interconnections after 200 cycles. The rate of interfacial IMCs growth in SAC305–0.05TiO2 interconnections is slower than that in the SAC305 interconnections. Cracks are formed in the IMC layer of the SAC305 interconnection after 200 cycles, which propagate through the whole IMC layer after 250 cycles. While for the SAC305–0.05TiO2 interconnection, no crack is observed until after 250 cycles. TiO2 nanoparticles doping could suppress the interfacial IMC growth, leading to an enhancement in the interconnection reliability under thermal shock. First-principles calculations are performed to further understand the mechanism for phase transformation of Ni-Cu-Sn IMCs and the reliability improvement of interconnections.

In-situ growth of electrically conductive MOFs in wood cellulose scaffold for flexible, robust and hydrophobic membranes with improved electrochemical performance

Electrically conductive metal-organic frameworks (EC-MOFs) have attracted great attentions in electrochemical fields, but their practical application is limited by their hard-to-shape powder form. The aims was to integrate continuously nucleated EC-MOFs on natural wood cellulose scaffold to develop biobased EC-MOFs membrane with robust flexibility and improved electrochemical performance for wearable supercapacitors. EC-MOF materials (NiCAT or CuCAT) were successfully incorporated onto porous tempo-oxidized wood (TOW) scaffold to create ultrathin membranes through electrostatic force-mediated interfacial growth and simple room-temperature densification. The studies demonstrated the uniform and continuous EC-MOFs nanolayer on TOW scaffold and the interfacial bonding between EC-MOF and TOW. The densification of EC-MOF@TOW bulk yielded highly flexible ultrathin membranes (about 0.3 mm) with high tensile stress exceeding 180 MPa. Moreover, the 50 %-NiCAT@TOW membrane demonstrated high electrical conductivity (4.227 S·m−1) and hydrophobicity (contact angle exceeding 130°). Notably, these properties remained stable even after twisting or bending deformation. Furthermore, the electrochemical performance of EC-MOF@TOW membrane with hierarchical pores outperformed the EC-MOF powder electrode. This study innovatively anchored EC-MOFs onto wood through facile process, yielding highly flexible membranes with exceptional performance that outperforms most of reported conductive wood-based membranes. These findings would provide some references for flexible and functional EC-MOF/wood membranes for wearable devices.

Effect of substrate heterogeneity and topology on epithelial tissue growth dynamics.

Tissue growth kinetics and interface dynamics depend on the properties of the tissueenvironment and cell-cell interactions. In cellular environments, substrate heterogeneity and geometry arise from a variety factors, such as the structure of the extracellular matrix and nutrient concentration. We used the CellSim3D model, a kinetic cell division simulator, to investigate the growth kinetics and interface roughness dynamics of epithelial tissue growth on heterogeneous substrates with varying topologies. The results show that the presence of quenched disorder has a clear effect on the colony morphology and the roughness scaling of the interface in the moving interface regime. In a medium with quenched disorder, the tissue interface has a smaller interface roughness exponent, α, and a larger growth exponent, β. The scaling exponents also depend on the topology of the substrate and cannot be categorized by well-known universality classes.

Highly enantioseparation in membrane-supported one-dimensional metal–organic framework hollow nanotube array prepared via mussel-inspired chemistry

High-enantioselective chiral metal–organic framework (CMOF) nanochannel membranes are of critical importance for chiral enantiomeric separations by taking advantage of their inherent high porosity and intrinsic chirality. However, traditional chiral membranes are still constrained by the permeability-selectivity trade-off, making it challenging to improve both simultaneously. This study described the structure of a new class of membrane-supported one-dimensional MOF hollow nanotube for transport and separation of chiral 1-phenylethanol (PE), utilizing a biomimetic polydopamine (PDA)-mediated counter-diffusion synthesis strategy. The inner cylindrical pore channel surface of polycarbonate track-etched membranes (PCTM) was modified by PDA chemistry to control the nucleation and interfacial growth of CMOF crystals, leading to the development of integrated chromatographic micro-column array membranes PCTM@PDA@Cu2C2D and PCTM@PDA@Cu2C2B with one-dimensional (1D) CMOF hollow nanochannels. Compared to PCTM@PDA@Cu2C2B, it was highlighted that the chiral membrane PCTM@PDA@Cu2C2D possessed the higher loading of Cu2C2D functional layer and more suitable steric chiral microenvironment, thus exhibited more outstanding permeability and selectivity for S-PE enantiomer with an enantiomeric excess value up to 90 % under an optimal guest concentration of 250 ppm at 30 °C for 1 h. The chiral membrane with 1D MOF hollow nanotubes, created by applying a gentle and simple method to introduce CMOF into the surface and pore channels of the substrate membrane, was expected to be utilized for the large-scale production of chiral separation membranes for industrial applications.

Improvement of weldability and fracture behavior of mild steel and A7075 aluminum alloy dissimilar friction stir welded joints by increasing welding speed

In this study, dissimilar friction stir welding of mild steel and A7075 aluminum alloy was conducted at a constant tool rotational speed (900 rpm) and different welding speeds of 100–400 mm/min with an interval of 100 mm/min. A thermocouple was employed to record the thermal cycle and the maximum reached temperatures of the A7075/steel interface during the joining process. The higher the welding speed, the lower the maximum temperature recorded during the joining process. Conducting the joining process at a high welding speed also enhanced the cooling rate and, thus, effectively contributed towards eliminating the thermal residual stresses and suppressing the interfacial intermetallic compounds growth. As a result, 100% joint efficiency with a steel base metal fracture was obtained for the joints fabricated at the welding speeds of 300 and 400 mm/min.

Crystal seeds induced interfacial growth of zirconium metal–organic framework membranes towards efficient hydrogen purification

Metal-organic frameworks (MOF) membranes with tunable pore size and versatile functions are promising for gas separation. Nevertheless, it still remains a great challenge to prepare defect-free high-valence MOF membrane with high stability. Herein, we report fabrication of high-valence Zr-MOF membranes by a crystal seeds induced interfacial growth approach. A MOF-802 seeding layer was deposited on the substrate surface, providing nucleation sites to induce intergrowth of MOF-802 into crystalline membrane when metal source and ligand diffuse in opposite directions to coordination react on the surface of porous substrate. The resulting continuous MOF-802 membrane displays excellent H2/CO2 separation performance with H2 permeance of ∼3540 GPU and selectivity of ∼23.1, transcending the upper-bound of state-of-the-arts. The MOF-802 membrane also shows high separation efficiency in the presence of water vapor owing to the excellent water stability of the framework. This work provides a facile approach and fundamental transport property for developing high-valence MOF molecular sieving membranes.

Flexible UiO-66-(COOH)2 metal–organic framework membranes for salinity gradient power generation

Metal-organic frameworks (MOFs) with high-density sub-nanometer pores and plenty of charged functional groups are ideal candidates for salinity gradient energy harvesting. However, synthesizing flexible and scalable MOF membranes with high performance for energy harvesting remains a challenge. Here we develop vertically aligned UiO-66-(COOH)2/polyethylene terephthalate (PET) membranes for salinity gradient energy harvesting. The PET/UiO-66-(COOH)2 membranes are fabricated by growing UiO-66-(COOH)2 crystals into nanochannels of the PET membranes via a nanoconfined interfacial growth method. The as-synthesized PET/UiO-66-(COOH)2 membranes are flexible with improved cation selectivity over PET membranes. The membrane produces a power density of 1.3 W m−2 under 0.5 M/0.01 M KCl solutions, which is better than the performances of membranes with a thickness of 10 µm. This work demonstrates that the MOF-functionalized PET membranes with high flexibility, scalability, and ion selectivity are promising candidates for energy harvesting.

Effect of the addition of Cu6Sn5 nanoparticles on the growth of intermetallic compounds at the interfaces of Sn3.0Ag0.5Cu solder joints

To solve the issue of overgrowth of intermetallic compounds (IMCs) at the interfaces of solder joints in electronic devices, this study has focused on the modification of Sn3.0Ag0.5Cu (SAC305) solder by adding Cu6Sn5 nanoparticles (NPs). It was found that Cu6Sn5 NPs would adsorb on the surfaces of the interfacial IMCs due to the high surface energy in solid–liquid reactions and resulted in a peculiarly ordered growth pattern of the new grains. In addition to this, a combined growth mechanism involving encapsulated and engulfed crystal growth of the interfacial IMCs was identified. The addition of Cu6Sn5 NPs was also calculated to increase the activation energy associated with interfacial IMCs growth during high-temperature service, thereby effectively inhibiting the overgrowth of interfacial IMCs. When the mass fraction of Cu6Sn5 NPs was 0.6 wt%, the activation energy for interfacial IMCs growth was the highest (31.9 kJ/mol).

Optimizing Na plating/stripping by a liquid sodiophilic Ga-Sn-In alloy towards dendrite-poor sodium metal anodes

Benefited by the abundant Na resources and high theoretical capacity of Na, rechargeable sodium metal batteries exhibit great potentials for next-generation energy storage systems. However, there are several key puzzles of Na anodes restricting the wide application, including high activity of Na metal, uncontrollable dendrite growth and unstable solid-electrolyte interface (SEI). In this work, a liquid alloy comprised of Ga, Sn and In was uniformly coated on commercial Cu foil in order to regulate the Na plating/stripping behaviors and thereupon enable stable sodium metal battery. The liquid sodiophilic Ga-Sn-In alloy on Cu foil (GSIC) can enhance the wettability of electrolyte and melted Na and decrease the Na nucleation overpotential. Based on the results of ex situ SEM and in situ optical microscopy, the Ga-Sn-In alloy coating layer can induce the uniform Na plating and decrease the volume expansion, enabling dendrite-poor capability. By taking NVP as cathode and optimal Na-GSIC as Na anode, the sodium metal full battery manifests a high reversible capacity of 108.7 mAh g−1 at the 1st cycles and offers 87.4 mAh g−1 (80.4% retention) at 5 C after 250 cycles. Such sodiophilic liquid alloy current collector would pave new pathway on designing feasible and highly stable Na metal anodes for sodium metal batteries.

Surfactant-free interfacial growth of graphdiyne hollow microspheres and the mechanistic origin of their SERS activity

As a two-dimensional carbon allotrope, graphdiyne possesses a direct band gap, excellent charge carrier mobility, and uniformly distributed pores. Here, a surfactant-free growth method is developed to efficiently synthesize graphdiyne hollow microspheres at liquid‒liquid interfaces with a self-supporting structure, which avoids the influence of surfactants on product properties. We demonstrate that pristine graphdiyne hollow microspheres, without any additional functionalization, show a strong surface-enhanced Raman scattering effect with an enhancement factor of 3.7 × 107 and a detection limit of 1 × 10−12 M for rhodamine 6 G, which is approximately 1000 times that of graphene. Experimental measurements and first-principles density functional theory simulations confirm the hypothesis that the surface-enhanced Raman scattering activity can be attributed to an efficiency interfacial charge transfer within the graphdiyne-molecule system.

Phase-field simulation of interface growth of magnesium metal anodes during electrodeposition

Mg-metal has abundant reserves and extremely high-volume capacity, making it an excellent choice as the negative electrode for low-cost, high-volume energy-density batteries. More and more studies have shown that there is still a problem of dendritic growth in Mg-metal. Here, we use the open-source MOOSE software package to establish a phase-field model for Mg-electrodeposition and study the dynamic morphological evolution of the growth of Mg-metal anode interfaces under different overpotentials in two dimensions. By studying the temporal-spatial distributions of ion concentration, chemical potential, and electric potential, we analyze the growth processes of Mg-metal anode interfaces under different applied overpotentials in detail. The results show that the Mg-metal anode interfaces only grow dendrites under applied overpotentials ranging from −0.24 to −0.30 V because the interface electrochemical reactions rate is greater than the interface ion transfer rate.

An optimizing hybrid interface architecture for unleashing the potential of sulfide-based all-solid-state battery

Sulfide-based all-solid-state lithium metal batteries are received tremendous focus due to the potential to deliver high energy density. Nevertheless, extremely unstable lithium/sulfide interface reaction and growth of unfavorable Li dendrites upon cycling remain challenging aspects and not yet fully settled. In this work, a lithophilic and high interfacial-energy hybrid interphase rich in chloride and Li-Ga alloy was in-situ constructed at Li/Li7P3S11 interface to tackle the vexing issue. Benefiting from the high interfacial energy and electronic insulation of LiCl in the hybrid interphase, lithium dendrites were effectively inhibited. In addition, the Li-Ga alloy-rich layer possesses excellent lithiophilicity and low diffusion energy, which can provide a uniform electric field distribution and induce rapid conduction of Li-ions. Consequently, the densification of Li/Li7P3S11 interface is achieved, which contributes to the decrease of interfacial impedance, uniform Li-ion flux and inhibition of continuous side reactions. Exalting, the Li symmetric cells with the Li-Ga alloy/LiCl (LGC) interlayer display high critical current density of 1.5 mA cm−2 and steady cycle for 1000 h at 0.3 mA cm−2 (0.3 mAh cm−2) at room temperature. Furthermore, the modified all-solid-state lithium battery also demonstrates an ultra-stable cycling. This work provides a reasonable design approach for the selection of interface layers in the all-solid-state lithium metal batteries (ASSLMBs) based on theoretical calculations, with the objective of attaining a stable Li/sulfide solid electrolyte interface.

Liquid Metal Interface for Two-Precursor Autogenous Deposition of Metal Telluride-Tellurium Networks.

Liquid metal-electrolyte can offer electrochemically reducing interfaces for the self-deposition of low-dimensional nanomaterials. We show that implementing such interfaces from multiprecursors is a promising pathway for achieving nanostructured films with combinatory properties and functionalities. Here, we explored the liquid metal-driven interfacial growth of metal tellurides using eutectic gallium-indium (EGaIn) as the liquid metal and the cation pairs Ag+-HTeO2+ and Cu2+-HTeO2+ as the precursors. At the EGaIn-electrolyte interface, the precursors were reduced and self-deposited autogenously to form interconnected nanoparticle networks. The deposited materials consisted of metal telluride and tellurium with their relative abundance depending on the metal ion type (Ag+ and Cu2+) and the metal-to-tellurium ion ratios. When used as electrode modifiers, the synthesized materials increased the electroactive surface area of unmodified electrodes by over 10 times and demonstrated remarkable activity for model electrochemical reactions, including HexRu(III) responses and dopamine sensing. Our work reveals the promising potential of the liquid metal-templated deposition method for synthesizing complex material systems for electrochemical applications.

Improved XFEM for 3D interfacial crack modeling

The conventional extended finite element method (XFEM) usually suffers from the crack tip enrichment for removing the blending elements. This may be inconvenient when treating the three dimensional (3D) and curved crack modeling since the crack tip enrichment is usually defined in the local coordinate system depending on the crack front. To avoid these shortcomings of the XFEM, an improved enrichment scheme is proposed for the 3D interfacial crack modeling. The proposed enrichment scheme removes the crack tip enrichment and two weight functions are introduced to capture the strong and weak discontinuities in the element including the crack front. The new enrichment scheme has advantages for the 3D curved interfacial cracks since all the enrichment functions are defined in the global system and it is unnecessary to introduce additional coordinate systems. Several benchmark problems including the mixed mode stress intensity factors (SIFs), anti-plane load and curved cracks are analyzed by the proposed method with the local refinement technology. Numerical results demonstrate that the proposed method can obtain accurate 3D energy release rate and SIFs. In addition, the proposed method enhances the applications of XFEM and has the potential abilities to the multiple-fields coupling and interfacial crack growth phenomena due to the fact that compatible enrichment functions are utilized.