Crystal Engineering Research Articles

Aqueous ammonium-ion battery capacity boosted with electrode preparation

Orbital electron tuning and crystal engineering improves the energy storage capacity of non-flammable batteries.

Modulation of electron transfer behavior on Fe2P-Co2P/NPC oxygen electrocatalyst by lattice cation substitution engineering and charge transport network design for rechargeable Zn-air batteries

Crystal structure modulation engineering on the lattice scale and charge transport network design on the micro/nano scale work together to endow oxygen electrocatalysts with high reactivity to fully release the capacity of Zn-air batteries (ZABs) as the next-generation green energy storage devices. Metal phosphide-based oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) electrocatalysts with tunable electronic structures, variable valence states, and moderate overpotentials are recognized as the most promising and ideal candidates for air cathodes. The cation substitution strategy overcomes the drawback that single metal phosphides with fewer active sites and high adsorption barriers are not sufficient to achieve satisfactory electrocatalytic performance. In this paper, the Fe2P-Co2P/NPC oxygen electrocatalyst employing lattice cation site substitution engineering and three-dimensional (3D) conductive network encapsulation strategies are constructed to successfully ensure fast electron transfer behavior and safe charge/discharge energy storage. Noteworthy, the presence of Schottky barriers at the interface of the two materials hinders the electron reflux, which promotes a unidirectional flow of electrons, and increases the electron condensation in the OER and ORR processes. Relying on these features, the Fe2P-Co2P/NPC-assembled liquid ZABs achieved power densities, specific capacities, and energy densities of 175.18 mW cm-2, 805.75 mAh gZn-1, and 958.84 Wh kg-1, respectively, and importantly good rate performances and stability were exhibited even under high-current-density operation. The corresponding flexible solid-state ZABs also possesses superior electrochemical activity and mechanical flexibility. This work paves the way for the construction of bifunctional oxygen electrocatalysts with high-speed electron transfer channels, thus advancing the development of wearable electronic devices.

Discovery, Characterization and Engineering of the Free l-Histidine C4-Prenyltransferase.

Prenylation of amino acids is a critical step for synthesizing building blocks of prenylated alkaloid family natural products, where the corresponding prenyltransferase that catalyzes prenylation on free l-histidine (l-His) has not yet been identified. Here, we first discovered and characterized a prenyltransferase FunA from the antifungal agent fungerin pathway that efficiently performs C4-dimethylallylation on l-His. Crystal structure-guided engineering of the prenyl-binding pocket of FunA, a single M181A mutation, successfully converted it into a C4-geranyltransferase. Furthermore, FunA and its variant FunA-M181A show broad substrate promiscuity toward substrates that vary in substituents of the imidazole ring. Our work furthers our knowledge of free amino acid prenyltransferase and expands the arsenal of alkylation biocatalysts for imidazole-containing small molecules.

A Review on the Influence of Crystal Facets on the Product Selectivity of CO2RR over Cu Metal Catalysts.

The electrocatalytic carbon dioxide reduction reaction (ECRR) is promising in converting environmentally harmful CO2 into useful chemicals, but the large-scale application of this technology is seriously limited by its low efficiency and selectivity. Cu-based electrocatalysts displayed attractive ability in converting CO2 to multiple products, and the product selectivity can be manipulated through various approaches. Among them, exposing specific crystal facets through crystal facet engineering has been proven to be highly effective in obtaining specific products and has attracted numerous researchers. However, to our knowledge, few reports have systematically summarized the relationship between the crystal facet control of Cu catalysts and the catalytic products. This review begins by outlining the general mechanism of CO2 electrocatalytic reduction on Cu-based catalysts, and then summarizes the preferences of low-index and high-index Cu facets regarding product selectivity and delves into the synergistic effects between facets (including different Cu facets and interactions between Cu and non-Cu facets) and their impact on CO2 reduction reaction (CO2RR). In addition, the study of the recently developed Cu single-atom catalysts in ECRR was also introduced. Finally, we provide an outlook on the development of high-performance Cu-based catalysts for applications in CO2RR. The purpose of this review is to provide a clear vein and meaningful guidance for the following studies over the crystal facet control of Cu-based electrocatalysts.

Engineering Thin Films of Silicon Phthalocyanines for Organic Thin Film Transistors

Metal phthalocyanines (MPc) show great promise as semiconductors due to their exceptional optoelectronic properties, high thermal and photochemical stability, and ability to be easily synthesized and functionalized for specific applications. The metal/metalloid ion in the center of the MPc ring can significantly influence the electronic, optical, and magnetic properties of the compound, as well as its solubility and stability. The majority of MPc, such as copper phthalocyanine (CuPc) are used as hole-transport materials (p-type) in organic electronics. Silicon phthalocyanines (R2-SiPc) are emerging semiconductors which predominantly moves electrons and have led to high performance n-type organic thin-film transistors (OTFTs). Their low synthetic complexity paired with their versatile axial group facilitates the finetuning of their chemical properties, solution properties and processing characteristics without significantly affecting their frontier orbital levels or their absorption properties. The crystal engineering and film forming characteristics of R2-SiPc semiconductors can be tuned through appropriate axial group functionalization, therefore facilitating their integration into both OTFTs and OPVs by solution processing or vapor deposition.Our group has developed families of R2-SiPc and integrated them into OTFTs with an emphasis on thin film processing and engineering of the interfaces for improved device performance. We have established structure property relationships of the final device performance as a function of 1) R2-SiPc axial groups and peripheral groups, 2) surface chemistry and composition and 3) thin film deposition conditions. I will also be discussing our recent work using advanced film characterization such as polarized Raman microscopy and synchrotron based scanning transmission x-ray microscopy to evaluate the resulting films and optimize the OTFT performance. Figure 1

Unveiling the Factors Influencing Different Nucleation Pathways and Liquid-Liquid Phase Separation.

Exploring nucleation pathways has been a research hot spot in the fields of crystal engineering. In this work, vanillin as a model compound was utilized to explore the factors influencing different nucleation pathways with or without liquid-liquid phase separation (LLPS). A thermodynamic phase diagram of vanillin in the mixed solvent system of water and acetone from 10 to 55 °C was determined. It was found that the occurrence of LLPS might be related to different nucleation pathways. Under the guidance of a thermodynamic phase diagram, Raman spectroscopy and molecular simulation were applied to investigate the influencing factors of different nucleation paths. It was found that the degree of solvation is a key factor determining the nucleation path, and strong solvation could lead to LLPS. Additionally, the molecular self-assembly evolution during the crystallization process was further investigated by using small-angle X-ray scattering (SAXS) and dynamic light scattering (DLS). The findings indicate that larger clusters with a diffuse transition layer may lead to LLPS during the nucleation process.

Crystal Engineering of Three Novel 1-D Chalcogenidostannates Using Lanthanide Complexes as Structure-Directing Agents: Synthesis, Structure, and Photoelectric Performance Evaluation

Crystal Engineering of Three Novel 1-D Chalcogenidostannates Using Lanthanide Complexes as Structure-Directing Agents: Synthesis, Structure, and Photoelectric Performance Evaluation

Deep learning of plausible bandgaps in dispersion curves of phononic crystals

Phononic crystals represent an interesting class of metamaterials that can be utilized to regulate or manipulate vibration, sound propagation, and thermal transport. Their useful features mainly arise from the bandgaps in their dispersion curves, preventing the passage of waves within specific frequency ranges. However, it is often costly and time-consuming to obtain the dispersion curves, and the reverse engineering of phononic crystals to have pre-defined bandgaps possesses even greater challenges. In this research, we address this issue by employing a deep artificial neural network to predict the bandgap ratio and the characteristics of plausible bandgaps, focusing on the localized resonance in columnar phononic crystals. We utilized two geometric parameters, i. e. the ratio of diameter and height of the cylindrical resonators relative to the lattice constant, achieving a determination coefficient of 0.9993 for predicting the characteristics of the bandgaps and 0.9827 for predicting the bandgap ratio. To verify the model and better understand its behavior, we introduce Shapley values. These values provide a comprehensive insight into how each geometric parameter influences the predicted bandgap ratios.

Multi-Template-Guided Synthesis of High-Dimensional Molecular Assemblies for Humidity Gradient-Based Power Generators.

Systematically orchestrating fundamental building blocks into intricate high-dimensional molecular assemblies at molecular level is imperative for multifunctionality integration. However, this remains a formidable task in crystal engineering due to the dynamic nature of inorganic building blocks. Herein, we develop a multi-template-guided strategy to control building blocks. The coordination modes of ligands and the spatial hindrance of anionic templates are pivotal in dictating the overall structures. Flexible multi-dentate linkers selectively promote the formation of oligomeric assembly ([TeO3(Mo2O2S2)3O2(OH)(C5O2H7)3]4- {TeMo6}) into tetrahedral cages ([(TeO3)4(Mo2O2S2)12(OH)12(C9H9O4P)6]8- {Te4Mo24} and [(AsO4)4(Mo2O2S2)12(OH)12(C9H9O6)4]12- {As4Mo24}), while steric hindrance from anionic templates further assists in assembling cages into an open quadruply twisted Möbius nanobelt ([(C6H5O3P)8(Mo2O2S2)24(OH)24(C8H10O4)12]16- {P8Mo48}). Among these structures, the hydrophilic-hydrophobic hybrid cage {Te4Mo24} emerges as an exemplary molecular model for proton conduction and serves as a prototype for humidity gradient-based power generators (HGPGs). The Te4Mo24-PVDF-based HGPG (PVDF=Poly(vinylidene fluoride)) exhibits notable stability and power generation, yielding an open-circuit voltage of 0.51 V and a current density of 77.8 nA cm-2 at room temperature and 90 % relative humidity (RH). Further insights into the interactions between water molecules and microscale molecules within the generator are achieved through molecular dynamics simulations. This endeavor unveils a universal strategy for synthesizing multifunctional integration molecules.

Multi‐Template‐Guided Synthesis of High‐Dimensional Molecular Assemblies for Humidity Gradient‐Based Power Generators

Systematically orchestrating fundamental building blocks into intricate high‐dimensional molecular assemblies at molecular level is imperative for multifunctionality integration. However, this remains a formidable task in crystal engineering due to the dynamic nature of inorganic building blocks. Herein, we develop a multi‐template‐guided strategy to control building blocks. The coordination modes of ligands and the spatial hindrance of anionic templates are pivotal in dictating the overall structures. Flexible multi‐dentate linkers selectively promote the formation of oligomeric assembly ([TeO3(Mo2O2S2)3O2(OH)(C5O2H7)3]4‐ {TeMo6}) into tetrahedral cages ([(TeO3)4(Mo2O2S2)12(OH)12(C9H9O4P)6]8‐ {Te4Mo24} and [(AsO4)4(Mo2O2S2)12(OH)12(C9H9O6)4]12‐ {As4Mo24}), while steric hindrance from anionic templates further assists in assembling cages into an open quadruply twisted Möbius nanobelt ([(C6H5O3P)8(Mo2O2S2)24(OH)24(C8H10O4)12]16‐ {P8Mo48}). Among these structures, the hydrophilic‐hydrophobic hybrid cage {Te4Mo24} emerges as an exemplary molecular model for proton conduction and serves as a prototype for humidity gradient‐based power generators (HGPGs). The Te4Mo24‐PVDF‐based HGPG (PVDF = Poly(vinylidene fluoride)) exhibits notable stability and power generation, yielding an open‐circuit voltage of 0.51 V and a current density of 77.8 nA cm‐2 at room temperature and 90% relative humidity (RH). Further insights into the interactions between water molecules and microscale molecules within the generator are achieved through molecular dynamics simulations. This endeavor unveils a universal strategy for synthesizing multifunctional integration molecules.

Ultrasensitive Self-Powered Flexible Crystalline β-Ga2O3-Based Photodetector Obtained through Lattice Symmetry and Band Alignment Engineering.

Due to its portable and self-powered characteristics, the construction of Ga2O3-based semiconductor flexible devices that can improve the adaptability in various complex environments have drawn great attention in recent decades. However, conventional Ga2O3-based flexible heterojunctions are based on either amorphous or poor crystalline Ga2O3 materials, which severely limit the performance of the corresponding devices. Here, through lattice-symmetry and energy-band alignment engineering, we construct a high-quality crystalline flexible NiO/β-Ga2O3 p-n self-powered photodetector. Owing to its suitable energy-band alignment structure, the device shows a high photo-to-dark current ratio (1.71 × 105) and a large detection sensitivity (6.36 × 1014 Jones) under zero bias, which is superior than most Ga2O3 self-powered photodetectors even for those based on rigid substrates. Moreover, the fabricated photodetectors further show excellent mechanical stability and robustness in bending conditions, demonstrating their potential practical applications in flexible optoelectronic devices. These findings provide insights into the manipulation of crystal lattice and energy band engineering in flexible self-powered photodetectors and also offer guideline for designing other Ga2O3-based flexible electronic devices.

Tailoring body center tetragonal allotropes Cx (x = 8, 12, 16, 20) with C(sp3) and hybrid C(sp3)/C(sp2): Crystal chemistry and ab initio investigations of the physical properties

Based on literature tetragonal ths topology C8 characterized by trigonal C(sp2), selective insertions of carbon induce large structural changes leading to C(sp3) C12 with dia topology after geometry optimizations to ground state structure using calculations within the quantum density functional theory DFT. Further crystal engineering operated on C12 lead to complete the series with novel C16 and C20. Such allotropes respectively characterized by ene (C=C) and propadiene (C=C=C) -like units beside C4 tetrahedra reveal hybrid C(sp3)/C(sp2) with complex stc topology. Alike ths C8, all three allotropes (C12, C16, and C20) identified in high symmetry I41/amd (No. 141) space group are cohesive with larger magnitude for C12 than for ths C8 and close energies for C16 and C20. Mechanical properties show diamond-like Vickers hardness HV for C12 (HV = 95 GPa) and smaller magnitudes for mixed C(sp3)/C(sp2) C16 (HV = 26 GPa) and C20 (HV = 47 GPa), noting that C8 with C(sp2) was found with the largest compressibility with HV = 19 GPa. Dynamically, all allotropes are stable from positive phonon acoustic and optic frequencies with the largest frequency magnitudes for C16 and C20 corresponding to CC and C=C=C vibrations respectively. Thermodynamically, the temperature changes of the specific heat CV show close agreement with diamond experimental values for C12 and larger magnitudes for the three other allotropes. Electronic band structure analyses reveal conductive C8 and C16, insulating C12 with a large band gap close to diamond's and semi-conducting C20 with small band gap.

Morphology induced defects and crystal facet engineering in CQD@CdS photocatalyst for efficient hydrogen generation

Morphology induced defects and crystal facet engineering in CQD@CdS photocatalyst for efficient hydrogen generation

Crystal engineering with novel antipyrine derivatives: Insights from X-ray diffraction, Hirshfeld surface analysis, and DFT calculations on intermolecular interactions

In this study, we report the synthesis, structural characterization by X-ray diffraction, vibrational (Infrared and Raman) investigation, Hirshfeld surface analysis, and DFT calculations of three new antipyrine derivatives (1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl) bearing amide groups (1–3). The compounds were synthesized in good yields and characterized spectroscopically. X-ray diffraction revealed that compound 1 crystallizes as a monohydrate in the monoclinic space group P21/c, while compound 3 also crystallizes as a monohydrate in the orthorhombic space group Pccn, exhibiting quasi-isomorphism with 1. Compound 2 crystallizes in the P21/c space group, forming H-bonded centrosymmetric dimers. The crystal packing is stabilized by NH···O and CH···O hydrogen bonds, along with CH···π interactions. FTIR and Raman spectroscopic analysis, supported by DFT calculations, identified key vibrational modes in the amide and pyrazole moieties. Hirshfeld surface analysis indicated that the molecular sheets are primarily formed by hydrogen bonds, with stabilization dominated by electrostatic energy contributions. DFT calculations (PBE0-D3/def2-TZVP) and QTAIM/NCIplot analyses revealed that the H-bonding interactions are energetically significant.

TpPa-1/{0 1 0}-BiVO4 S-scheme heterojunction fabricated on specific crystal facets for highly efficient H2O2 artificial photosynthesis

The rational fabrication of inorganic–organic S-scheme heterojuncion hybrid photocatalysts on specific crystal facets is challenging but significant. Herein, we report that TpPa-1-covalent organic framework (COF) selectively grown on {010} crystal facets of decahedral BiVO4 (TpPa-1/{010}-BVO, denoted as TB-1) was synthesized through a surfactant-assisted microwave solvothermal route. The experimental results and theoretical calculations showed that TB-1 was more beneficial to separation of photogenerated carriers than the heterojunction randomly formed at all crystal facets ({010} + {110}) of BiVO4 (TpPa-1/BVO, denoted as TB-2). As a result, photocatalytic oxygen reduction reaction (ORR) activity for H2O2 production over TB-1 reached 723 μmol·gcat−1·h−1, which is 72.3-times, 5.7-times, and 2.4-times higher than individual BiVO4 (10 μmol·gcat−1·h−1), TpPa-1 (127 μmol·gcat−1·h−1), and TB-2 (305 μmol·gcat−1·h−1). In addition, the introduction of TpPa-1 could inhibit the decomposition of H2O2. This study not only provides a new hybrid photocatalyst for artificial H2O2 production but also highlights the importance of crystal facet engineering in the design of highly efficient photocatalysts.

Effect of Metal-Organic Frameworks with Different Ligand Structures (ZIF-11 & ZIF-23) on the Optoelectronic Performance of Perovskite Photodetectors.

Crystal engineering using passivation to reduce perovskite defects is crucial to improving the quality of perovskite crystals and optoelectronic properties. Because of their unique properties, metal-organic framework materials have been used as an emerging and effective passivator for perovskite materials and optoelectronic devices. This paper focuses on the differences in the optoelectronic properties of zeolite imidazolium ester framework materials (ZIF-11 & ZIF-23) doped with different conjugated ring ligands for perovskite photodetectors. This paper proposes a simple and effective method to dope zeolite imidazolium ester framework nanoparticles (ZIF-11 & ZIF-23) into organic-inorganic perovskite MAPbI3 films. The crystalline quality of the perovskite films was improved after doping with ZIF-11 and ZIF-23. Meanwhile, the performance of the planar photoconductive devices was significantly improved. The photoresponsivity of the photodetector doped with ZIF-23 was 0.185A/W, and the detectivity was 4.22 × 1012 Jones. The photoresponsivity of the photodetector doped with ZIF-23 was 0.164 A/W, and the detectivity was 3.27 × 1012 Jones. The devices maintained long-time operational stability, operating without significant degradation for 480 s under the 1.2 V bias voltage operating condition. In addition, we observed a significant suppression of the ion migration process in ZIF-23 for a voltage-controlled ion migration process. The potential application of perovskite and MOF heterojunction materials for image information acquisition and storage is demonstrated.

Crystal Field Engineering Inducing Transformation from Narrow Band of Eu3+ to Broadband of Eu2.

The complete transformation from narrow peak emission of Eu3+ to broadband emission of Eu2+ was first realized in La1-xSr2+xAl1-xSixO5:Eu series solutions relying on crystal field engineering and adjustment of synthesis parameters. The original red phosphor La0.97Sr2AlO5:0.03Eu3+peaks at 703 nm originated from 5D0 →7F4 transition of Eu3+ under 395 nm excitation. As the x value regularly increased, Sr2SiO4-type green phosphor La0.17Sr2.8Al0.2Si0.8O5:0.03Eu2+ was synthesized at x = 0.8, which can be efficiently excited by UV/blue light chips. Moreover, when x > 0.975, Sr3SiO5:Eu2+ type broadband orange phosphor Sr2.945Al0.025Si0.975O5:0.03Eu2+ with excellent thermal stability (91.3% peak intensity at 150 °C) was obtained. Variations in the crystal structure, phase, and luminescence properties were studied in detail. We hope this work can provide a reference that solid solution between distinct but structurally related systems is a strategy to explore the possible phosphors for phosphor-converted light-emitting diodes.

Unlocking Chlorine Oxide‐Based Ultra‐Wideband Near‐Infrared Phosphor and Advancing Spectral Performance via Lattice Engineering

AbstractNear‐infrared (NIR) phosphor‐converted light–emitting diodes (pc‐LEDs) are increasingly used in night vision, surveillance, and biomedicine. A major challenge is to identify a phosphor that efficiently converts blue light into wideband NIR emission. In this paper, a rare‐earth divalent europium (Eu2+)‐activated halogen oxide (Sr3GeO4Cl2) phosphor is unlocked via a high‐temperature solid‐state reaction. The Sr3GeO4Cl2:Eu2+ phosphor emits a wide spectrum (500–950 nm) with a peak at 700 nm when excited by 450 nm blue light. Extended X‐ray absorption fine structure (EXAFS) analysis reveals that the NIR emission primarily originates from Eu2+ ions, and the Eu─O bond length closely resembles the Sr─O bond length. Lattice engineering, specifically Ge/Si cation substitution, increased Eu2+ incorporation into the crystal lattice, boosting luminescence intensity by 75%–122% and quantum efficiency from 15% to 26%. This is related to the combined effect of reduced non‐radiative energy transfer and changes in the local lattice structure of Eu2+. A NIR pc‐LED device using the optimized phosphor showed a photoelectric efficiency of 16.5% and an optical output of 25.07 mW at 100 mA. This study not only explores new Eu2+‐activated NIR phosphors but also highlights the importance of crystal engineering to enhance luminescence properties, guiding future research for efficient NIR pc‐LED development.

DNA-mediated assembly of Au bipyramids into anisotropic light emitting kagome superlattices.

Colloidal crystal engineering with DNA allows one to design diverse superlattices with tunable lattice symmetry, composition, and spacing. Most of these structures follow the complementary contact model, maximizing DNA hybridization on building blocks and producing relatively close-packed lattices. Here, low-symmetry kagome superlattices are assembled from DNA-modified gold bipyramids that can engage only in partial DNA surface matching. The bipyramid dimensions and DNA length can be engineered for two different superlattices with rhombohedral unit cells, including one composed of a periodic stacking of kagome lattices. Enabled by the partial facet alignment, the kagome lattices exhibit lattice distortion, bipyramid twisting, and planar chirality. When conjugated with Cy-5 dyes, the kagome lattices serve as cavities with high-density optical states and large Purcell factors along lateral directions, leading to strong dipole radiation along the z axis and facet-dependent light emission. Such complex optical properties make these materials attractive for lasers, displays, and quantum sensing constructs.

Precise Pore Engineering of Zirconium Metal‐Organic Cages for One‐Step Ethylene Purification from Ternary Mixtures

AbstractOne‐step purification of ethylene from ternary mixtures (C2H2, C2H4, and C2H6) can greatly reduce the energy consumption of the separation process, but it is extremely challenging. Herein, we use crystal engineering and reticular chemistry to introduce unsaturated bonds (ethynyl and alkyne) into ligands, and successfully design and synthesized two novel Zr‐MOCs (ZrT‐1‐ethenyl and ZrT‐1‐alkyne). The introduction of carbon‐carbon unsaturated bonds provides abundant adsorption sites within the framework while modulating the pore window size. Comprehensive characterization techniques including single crystal and powder X‐ray diffraction, as well as electrospray ionization time‐of‐flight mass spectrometry (ESI‐TOF‐MS) confirm that ZrT‐1‐ethenyl and ZrT‐1‐alkyne possess an isostructural framework with ZrT‐1 and ZrT‐1‐Me, respectively. Adsorption isotherms and breakthrough experiments combined with theoretical calculations demonstrate that ZrT‐1‐ethenyl can effectively remove trace C2H2 and C2H6 in C2H4 and achieve separation of C2H2 from C2H4 and CO2. ZrT‐1‐ethenyl can also directly purify C2H4 in liquid solutions. This work provides a benchmark for MOCs that one‐step purification of ethylene from ternary mixtures.