Crystal Planes Research Articles

Regulating Crystalline Phase/Plane of Polymer Electrolyte for Rapid Lithium Ion Transfer

Electronic‐rich functional groups and flexible segments have long been perceived to be the decisive factors influencing lithium‐ion transfer in polymer electrolytes, while crystallinity is regarded as the great scourge. Actually, the research on the influence of crystalline phase and crystalline plane is still in scarcity. Herein, taking poly(vinylidene fluoride)‐hexafluoropropylene (PVDF‐HFP) as an example, new (111/201) crystal planes (belonged to β‐phase) are regulated by dissolving process and clarified by Synchrotron radiation X‐ray diffraction and X‐ray diffraction. Density functional theory calculation indicates that the newly exposed (111/201) crystal planes provide higher binding energy with lithium ions and are conducive to provide more ion transport channels.7Li nuclear magnetic resonance of new crystalline planes contained PVDF‐HFP based electrolyte shows lower field and sharper peak intensity, further proves the rapid lithium ion transfer. Therefore, a high ionic conductivity of 6.42×10−4 S cm−1 and a large lithium‐ion transfer number of 0.7 are achieved. This study offers a new insight into the influence of crystalline phase and crystalline plane on the transfer of lithium ion for polymer electrolytes.

Zero-Dimensional Lead-Free Perovskite Single Crystals for the Sensitive Detection of Visible Light and X-Rays.

The excellent performance and facile fabrication process of perovskite semiconductor materials make them highly promising candidates in the field of optoelectronic devices. Whether for visible light or X-rays, detectors with low detection limits can better identify weak light signals, significantly reducing the intensity of the received light source during device operation. In particular, for X-ray detectors, reducing X-ray dosage can greatly enhance the safety of X-ray imaging technology. This work develops detectors with low detection limit based on zero-dimensional (0D) MA3Bi2I9 single crystals. The anisotropy of MA3Bi2I9 and its influence on the detector's performance were investigated in detail. Detectors perpendicular to the (001) crystal plane have better weak light detection capability and require significantly less light intensity compared to devices parallel to the (001) crystal plane. X-ray detector with a limit of detection (LoD) of 0.68 nGyair s‒1 and sensitivity of 5072 μC Gyair‒1 cm‒2 was obtained. The present study offers comprehensive insights into the operational mechanism of layered perovskites, which can provide valuable guidelines for future designs and fabrications of highly sensitive photo and X-ray detectors.

Trisodium Citrate‐Assisted Synthesis of Edge‐Abundant Nickel‐Iron Layered Double Hydroxides for Efficient Oxygen Evolution Reaction

AbstractThe edges of layered double hydroxides (LDHs) display an exceptionally more efficient oxygen evolution reaction (OER) activity than the (001) basal plane as demonstrated by both theoretical calculations and experimental studies. However, a controllable synthesis method of LDHs with abundant edges has yet to be described. Herein, we report a strategy enabling the synthesis of nickel‐iron LDHs with abundant edges (NiFe LDHs‐E) based on the use of citrate anions as the structure‐directing agent. The edge density is characterized using spectroscopy techniques and its OER performance is compared with that of nickel‐iron LDHs with abundant basal planes (NiFe LDHs‐B). In alkaline electrolyte (1 M KOH), NiFe LDHs‐E exhibits excellent OER activity with very low overpotential (235 mV at 10 mA cm−2) and current densities (at η = 320 mV) up to sixfold higher than those of NiFe LDHs‐B. Density functional theory (DFT) calculations confirm the high OER activities ascribed to the abundant side‐plane edges with optimal strength of binding of OER intermediates. Overall, a comprehensive investigation, employing both experimental and computational methodologies, yields new insights to fabricate superior catalysts meticulously designed with specific crystal planes and unveils the crucial structural attributes, thus unleashing the limitless potential of the catalytic domain.

Effective Dopants Pb and Pb‐SiW12 to Enhance Sb2S3‐Based Photodetector Performance

AbstractSb2S3 has excellent photovoltaic properties, but the performance of its photovoltaic devices still needs to be improved. The main issues hindering its photovoltaic performance are the poor carrier transport ability and the significant charge recombination. Doping strategies play a key role in addressing these issues. This study investigates the effect of Pb(CH3COO)2 (Pb) and [Pb(DMF)7]2[SiW12O40] 2DMF (Pb‐SiW12) doping on the photovoltaic properties of Sb2S3 thin films. It is found that the intensity of diffraction peaks on the (130) crystal plane of Pb‐doped Sb2S3 and the (221) crystal plane of Pb‐SiW12@Sb2S3 is increased, which enhances the crystallinity of the films. Meanwhile, Pb and Pb‐SiW12 doping narrow the bandgap (1.69 eV) of Sb2S3 to 1.65 eV and 1.62 eV. Electrochemical tests show that the carrier concentration and carrier lifetime are increased. The Pb‐doped Sb2S3 photodetector photocurrent of 14 μA, 7 times higher than the 2 μA pristine Sb2S3 photodetector. It exhibits a responsivity of 13.9 mA/W and detectivity of 1.2×1011 Jones. The Pb‐SiW12@Sb2S3 photodetector photocurrent is 11 μA. Pb‐SiW12 can immobilize Pb while reducing the amount of Pb. The methodology in this work provides a way to improve the performance of Sb2S3 thin‐film photodetectors.

Cu2O@Cu-composed hollow spheres capable of Generating Rich reactive oxygen species for efficient photodynamic antibacterial application

Cuprous oxide (Cu2O), which has an appropriate band gap, is widely used as a marine antifouling biocide. This makes it increasingly valuable for photocatalytic antibacterial applications. Using crystal engineering technology to create Cu2O with tailored Cu2O/Cu interfaces and crystal planes can effectively enhance its performance but presents challenges. Herein, we report a simple wet chemical method for the controlled preparation of Cu2O@Cu hollow heterostructure. Experimental results demonstrate that the prepared composites exhibited highly efficient and broad-spectrum photocatalytic antibacterial effects against both Gram-negative and Gram-positive bacteria, achieving 100% antibacterial efficiency under 10 min of irradiation, much more effective than the bulk Cu2O. Characterization results show that a hollow spherical structure consisted of fine Cu2O@Cu nanoparticles in their wall, and the generated interfaces facilitated the migration and separation of photogenerated charge carriers and promoted the formation of hydroxyl radicals with stronger oxidizing abilities. Meanwhile, the Cu outside layer of each Cu2O@Cu particle not only acted as a shield to protect Cu2O from corrosion but also served as an electron acceptor to efficiently transfer photogenerated electrons, thereby demonstrating highly effective and stable antibacterial performance. This study not only offers a valuable reference for developing highly efficient and universal photocatalytic materials but also provides insight into the chemical reaction in the photocatalytic antibacterial process.

Influence of atomic coordination on the activity of lattice oxygen and catalytic oxidation of toluene over regular Cu2O crystalline

VOCs oxidation over transition metal catalyst is commonly understood via the Mars-van Krevelen mechanism involving the crucial role of lattice oxygen (OL) activity, however, how it is influenced by atomic coordination is still unclear. Herein, we use model catalysts of Cu2O-cub, Cu2O-oct and Cu2O-dod with crystal planes of (100), (111) and (110), respectively, to investigate the OL activity and catalytic oxidation of toluene. The activity of Cu2O-oct is found to be the highest, followed by Cu2O-cub and Cu2O-dod. Experiments results combined with density functional theory show that, although low di-coordinated O atoms leads to the lowest surface oxygen vacancy formation energy (2.47eV) and the highest surface OL activity of Cu2O-cub, it cannot determine the activity. The lowest bulk oxygen vacancy formation energy (3.16eV) in Cu2O-oct terminated with tri-coordinated O atoms and open surface can accelerate the migration and replenishment of OL, thereby promoting the catalytic activity.

High quality perovskite thin films synthesized by low-temperature supercritical carbon dioxide annealing method

Thermal annealing is a conventional method used to eliminate residual solvents in perovskite films, reducing internal and interfacial defects. However, due to the high saturation vapor pressure of the residual solvent dimethyl sulfoxide, it is difficult to quickly remove the residual solvent at low temperatures. In this paper, the high permeability and diffusion of supercritical CO2 (ScCO2) were used to quickly remove the residual solvent of film at low temperatures. The effects of ScCO2 annealing on the surface morphology, residual solvents, internal and interfacial defects of perovskite thin films were investigated. The experimental results indicate that ScCO2 annealing significantly improves the removal efficiency of residual solvents compared to low-temperature annealing, effectively minimizing internal and interfacial defects. Additionally, the interaction energy of CO2 with the perovskite crystal plane reduces the surface energy of the crystal, resulting in a significant increase in the average grain size of the crystal by about 91.2%. Notably, the average crystal size of the film prepared by chlorobenzene as an antisolvent increased from 209.35 nm to 704.57 nm. The high penetration of ScCO2 also promoted uniform crystal growth, thereby reducing crystal structure deformation and defects. The carrier lifetime of perovskite thin films after ScCO2 annealing increased by over 58.8% on average.

Novel Chiral Wire–like Bi Nanoparticle Assembly: In–situ Studies on Structural Evolution from (BiO)2CO3 Nanowires Under Electron–beam Irradiation

The temporal in-situ observation is of great benefit to the understanding of synthetic strategies in materials science. Herein, for the first time, we report the in–situ monitoring of decomposition of (BiO)2CO3 nanowires under the electron–beam irradiation using a transmission electron microscope (TEM), that produces an intriguing chiral wire–like bismuth (Bi) nanoparticle assembly. The decomposing process of (BiO)2CO3 nanowire was characterized by employing three-dimensional (3D) TEM, selected area electron diffraction (SAED), and high–resolution TEM (HRTEM). It was demonstrated that the (BiO)2CO3 nanowire decomposed into Bi nanoparticles through Bi6O7 intermediates. Bi6O7 nanodot arrays appeared along (013) and () crystal planes of (BiO)2CO3 nanowire with a single orientation relationship of {[001]BCO‖[001]BO, [010]BCO‖[100]BO}. A chiral helix of Bi–nanoparticle assembly formed in random orientation through oxygen–removal of Bi6O7. This work has not only observed the in–situ decomposing process of (BiO)2CO3 nanowires but also demonstrated a facile approach for generating novel chiral Bi nanostructure via electron–beam irradiation, implicating the potential of developing nanomaterials with new tunable nanostructures.

Novel biocomposite of ionic cross-linked chitosan and acid-treated potato (Solanum tuberosum L.) peel agro-waste for highly efficient removal of methylene blue dye from water.

In this study, a biocomposite material (CS-OXA/PP-SA) composed of ionic crosslinked chitosan-oxalate (CS-OXA) and chemically modified lignocellulosic biomass (potato (Solanum tuberosum L.) peel-H2SO4 acid, PP-SA) was synthesized to serve as a bioadsorbent for removing methylene blue (MB) dye from aquatic systems. The research utilized response surface methodology (RSM) to evaluate the effects of three variables: CS-OXA/PP-SA dosage (0.02 to 0.08 g), pH (4 to 10), and duration (10 to 40 min) on MB dye adsorption. The investigation of the BET surface area of the CS-OXA/PP-SA composite revealed that it had a total pore volume of 0.0261 cm3/g, a surface area of 8.26 m2/g, and an average pore diameter of 12.67 nm. The XRD pattern shows a peak at 20.5°, confirming the crystalline CS within the composite, and another at 35°, attributed to the (004) crystal plane of cellulose in PP-SA. These peaks verify the successful integration of CS and PP-SA into the biocomposite. The optimal conditions identified include an adsorbent dose of 0.055 g, a solution pH of approximately 10, and a contact duration of 29.8 min. The optimal MB dye removal efficiency achieved under these parameters was 90.9 %. The results demonstrated that the adsorption of MB onto CS-OXA/PP-SA aligns closely with the pseudo-first-order kinetic model, suggesting a physisorption-dominated process. Additionally, the adsorption isotherm fitting to the Freundlich model highlights the heterogeneous nature of the adsorbent surface and the multilayer adsorption mode. The CS-OXA/PP-SA composite demonstrated a maximum adsorption capacity of 314.92 mg/g for MB dye. The adsorption mechanism is attributed to electrostatic interactions, hydrogen bonding, and n-π stacking interactions. The findings suggest that CS-OXA/PP-SA is a highly effective bioadsorbent for treating dye-contaminated wastewater. This study introduces a sustainable and eco-friendly approach to developing efficient adsorbents for the removal of cationic dyes from contaminated water. The biocomposite demonstrates high adsorption capacity, cost-effective production, and renewable sources, offering an innovative and practical solution for wastewater treatment while adhering to green chemistry principles.

Nature-Inspired Antimicrobial Agents: Cinnamon-Derived Copper Oxide Nanoparticles for Effective Aspergillus Niger Control.

The emergence of resistant bacterial and fungal strains poses significant challenges in various industrial processes including food, medicines, and leather industry. It necessitates the development of novel and effective antimicrobial agents. In the present work, we have developed an ecofriendly and sustainable approach to synthesize silver-doped copper oxide nanoparticles by using cinnamon bark extract (C-CuO/Ag). The nanoparticles were characterized via UV-visible spectroscopy at 190-800 nm, FT-IR, SEM-EDAX, XRD, and further subjected to determine antimicrobial potential, minimum inhibitory concentration (MIC), and anti-biofilm potential against both bacterial and fungal species. UV-visible spectrum showed maximum absorption at 210 nm in ultraviolet range and 419 nm in visible range. Various strong and weak peaks were obtained in FT-IR spectra, which defined the presence of corresponding functional groups in C-CuO/Ag nanoparticles. SEM analysis revealed the tightly packed confirmation, while EDS confirmed the elemental analysis of C-CuO/Ag nanoparticles. XRD spectrum of C-CuO/Ag nanoparticles showed strong diffraction peaks at 2Ө of 31.92˚, 35.67˚, and 48.51˚, which confined with the plane indices of (-110), (111), and (-202), respectively, while weak diffraction peaks at 2Ө of 56.31˚, 58.9˚, and 77.4˚, which leads to the crystal planes of (202), (-220), and (311), respectively. Antimicrobial assays showed clear zones of inhibition against microbial strains as maximum inhibition diameter was observed against Aspergillus niger (31.5 ± 0.7 mm) followed by Escherichia coli (30.1 ± 0.3 mm) and Staphylococcus aureus (29.5 ± 0.7 mm). These findings provide support clear evidence that CuO nanoparticles can serve as potent antibacterial and antifungal compounds against highly resistive and pathogenic microbial strains.

CL‐20/4,5‐MDNI crystal growth and morphology under different conditions: A molecular dynamics simulation

AbstractCL‐20/4,5‐MDNI exists in two cocrystal forms with different stoichiometric ratios of 1:1 and 1:3. The properties (such as blast performance, thermal performance, sensitivity, and density) of the two cocrystals are significantly different, but both cocrystals are expected to become new high‐energy insensitive explosives and have good applications. The AE model and molecular dynamics were used to simulate the crystal morphology and important crystal planes of 1:1 and 1:3 CL‐20/4,5‐MDNI under vacuum conditions, as well as in five solvents and different temperatures. 1:1 CL‐20/4,5‐MDNI has five main growth crystal planes of (002), (102), (111), (020) and (021), of which (002) has the largest proportion. 1:3 CL‐20/4,5‐MDNI has six main growth crystal planes of (001), (010), (011), (100), (101) and (111), of which (001) accounts for the largest proportion. The crystal morphology aspect ratio of 1:3 CL‐20/4,5‐MDNI in acetonitrile and 1:1 CL‐20/4,5‐MDNI in methanol are 1.936 and 1.680, respectively. The results were consistent with the experiments, which has certain guiding significance for CL‐20/4,5‐MDNI to obtain a crystal morphology closer to spherical shape.

Catalyst-free in-plane growth of high-quality ultra-thin InSb nanowires

InSb nanowires (NWs) show an important application in topological quantum computing owing to their high electron mobility, strong spin–orbit interaction, and large g factor. Particularly, ultra-thin InSb NWs are expected to be used to solve the problem of multiple sub-band occupation for the detection of Majorana fermions. However, it is still difficult to epitaxially grow ultra-thin InSb NWs due to the surfactant effect of Sb. Here, we develop an in-plane self-assembled technique to grow catalyst-free ultra-thin InSb NWs on Ge(001) substrates by molecular-beam epitaxy. It is found that ultra-thin InSb NWs with a diameter as small as 17 nm can be obtained by this growth manner. More importantly, these NWs have aspect ratios of 40–100. We also find that the in-plane InSb NWs always grow along the [110] and [11¯0] directions, and they have the same {111} facets, which are caused by the lowest-surface energy of {111} crystal planes for NWs grown with a high Sb/In ratio. Detailed structural studies confirm that InSb NWs are high-quality zinc blende crystals, and there is a strict epitaxial relationship between the InSb NW and the Ge substrate. The in-plane InSb NWs have a similar Raman spectral linewidth compared with that of the single-crystal InSb substrate, further confirming their high crystal quality. Our work provides useful insights into the controlled growth of in-plane catalyst-free III–V NWs.

Cellulose-assisted one-step liquid-phase synthesis of cuprous oxide nanoframes for efficient degradation of 4-nitrophenol: Oxygen vacancy engineering and crystal plane effect

In this study, we report a cuprous oxide nano-framework catalyst with abundant oxygen vacancies and multiple exposed crystalline surfaces. The catalyst exhibits excellent catalytic performance in the hydro-reduction reaction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) with good reusability. Experimental and theoretical simulations showed that the construction of oxygen vacancies induced a change in the corresponding atomic configuration and electronic properties of the catalyst, which contributed to the improvement of the adsorption of 4-NP and the capture and activation of H atoms, thus accelerating the transfer process of reactive hydrogen and electrons to 4-NP using the catalyst as a mediator. In addition, the rough surface of the nano-framework exposed a variety of crystalline facets, among which the (210) facets possessed more suitable H atom adsorption energy and more electron transfer compared to the (100) facet, which further improved the hydrogenation performance of the catalyst. This study provides a catalyst design strategy based on the synergy of oxygen vacancies and crystalline surfaces for the efficient degradation of organic pollutants.

Investigation of anisotropic characteristics in ultra-precision grinding of sapphire crystal planes and strategies for suppression

Sapphire has been extensively utilized due to its excellent infrared transmittance. The demand for sapphire optical components has transitioned from flat geometries to more complex curved geometries. This transition necessitates the processing of sapphire from a single crystal plane to multiple crystal planes, presenting a significant challenge. To gain a comprehensive understanding of the anisotropy present in the machining of sapphire multiple crystal planes and to explore strategies for its suppression, various grinding wheels were employed for ultra-precision grinding of the sapphire A-plane, C-plane, M-plane, N-plane, and R-plane. This investigation encompassed multiple facets, including surface roughness, surface topography, residual stress, acoustic emission time-frequency characteristics, and infrared transmittance. A thorough analysis was conducted on the morphology of corrosion damage and the anisotropic mechanisms involved in sapphire ultra-precision grinding, as well as the resulting grinding quality following the implementation of suppression strategies. The findings indicate that the A-plane, C-plane, and M-plane of sapphire exhibit significant anisotropic characteristics when ground with the D25 resin bond grinding wheel, whereas the N-plane and R-plane do not display such characteristics. Furthermore, the application of the D3 ceramic bond grinding wheel effectively suppresses the anisotropy in the grinding of different sapphire crystal planes, achieving a high-quality surface finish with a ductile domain exceeding 90 %, and ensuring high uniformity in the ultra-precision grinding of various sapphire crystal planes.

Ionization loss spectra of high-energy protons in an oriented crystal at various incidence angles with respect to a crystalline plane

The ionization energy loss distributions (spectra) of high-energy protons in oriented silicon crystals are considered on the basis of computer simulation. Evolution of the spectra with the change of the angle θ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ heta $$\\end{document} between the particle momentum and the crystal (110) plane is investigated. It is shown that both the most probable and the average energy loss change non-monotonically with the increase of θ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ heta $$\\end{document}. While at small θ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ heta $$\\end{document} these losses are lower than their values in a disoriented crystal, at larger θ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ heta $$\\end{document} they can be higher than these values. The dependence of the most probable energy loss on θ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ heta $$\\end{document} contains a discontinuity, which however might be challenging to register experimentally. Additionally, the influence of dechanneling and the incident beam divergence on the spectra of planar channeled protons is demonstrated.

Study on the preparation and wear properties of laser cladded Incoel718/WC gradient composite coatings

Laser cladding was employed to fabricate gradient coatings of Inconel718 + 10 wt%WC, Inconel718 + 30 wt%WC, and Inconel718 + 50 wt%WC on the surface of 42CrMo steel substrate, aiming to improve its wear resistance. The findings indicate that the Inconel718/WC gradient composite coatings have strong metallurgical bonding with the 42CrMo steel substrate. The Inconel718/WC gradient composite coating consists of γ-(Ni, Fe), WC and W2C phases. The microstructure of the Inconel718/WC gradient composite coating mainly comprises planar crystals, columnar crystals, dendrites, and fine equiaxed dendrites, distributed from the bottom to the top. The hardness of the Inconel718/WC gradient composite coating shows a gradient distribution, with the topmost layer having an average hardness of 784.3 HV0.2, approximately 3.4 times that of the substrate. Compared to the substrate, the Inconel718/WC gradient composite coating demonstrates superior wear resistance, with the friction coefficient and wear mass loss rate reduced by 31.57 % and 76.19 %, respectively; the substrate exhibits adhesive wear, while the gradient coating shows abrasive wear. This research provides a valuable reference for the engineering application of 42CrMo steel as a structural material in additive manufacturing.

Intralayer Molecular Packing Coefficient as One Packing Characteristic of Planar Layer-Stacked Crystals and Its Dominators

Intralayer Molecular Packing Coefficient as One Packing Characteristic of Planar Layer-Stacked Crystals and Its Dominators

Oxygen vacancies-promoted oxidative esterification of ethylene glycol to methyl glycolate over Au/ZnO catalyst

Au/ZnO-x with different morphologies were prepared by controlling the amount of (NH4)2CO3 (x) using deposition precipitation method and applied for the one-step oxidative esterification of methanol and ethylene glycol (EG) to methyl glycolate (MG). The catalytic performance of Au/ZnO-x firstly increases and then decreases with the increase of the amount of (NH4)2CO3, and the maximum is achieved in Au/ZnO-4, with EG conversion of 89.6 % and 96.4 % selectivity to MG, significantly higher than the reported Au-based catalysts. The superior catalytic behavior is mainly derived from the most oxygen vacancy concentration (Vo+) accompanied with the highest I100/I101 ratio at moderate (NH4)2CO3 dosage, promoting the adsorption and dissociation of O2 molecular. Specifically, different preferential growth ratio between the (100) and (101) crystal plane accounts for Au/ZnO-2, Au/ZnO-4, and Au/ZnO-6 with lamellar stacking morphology, orderly layer structure, and randomly stacked layers, respectively. Significantly, it was found that there was a linear positive correlation between the Vo+ and the EG conversion. Innovatively, the oxygen vacancy played the predominant role in Au/ZnO-x for the catalyzed oxidative esterification of EG, which provided a new idea for the design of efficient catalysts for the reaction.

Investigations on symbol regression for improving the prediction accuracy of gas-metal adsorption energies in machine learning

Adsorption energy plays a crucial role in surface catalytic reactions and influences the performance of the catalysts. Machine learning offers a novel approach for the computation of adsorption energy. The selection of a crystal plane is critical for the calculation of the adsorption energy, with current research focusing on low-index crystal planes. The prediction of catalytic performance is challenging because of the complexity arising from the surface reactions occurring on multiple crystal planes. However, this challenge can be resolved by introducing effective descriptors and utilizing advanced machine learning methods. This study collected data from various sources, such as databases, literature, and Density Functional Theory calculations, and utilized machine learning to predict the adsorption energies of prevalent adsorbates on multiple crystal planes of several platinum group metals in catalytic reactions. New structural descriptors were developed by leveraging the expertise of material researchers, and feature engineering techniques were employed to improve the predictive accuracy of the machine learning model. To prevent data loss and detect potential regularities, new features are created using symbolic regression. The introduction of these new features significantly enhanced the model's performance, increasing R2 from 0.885 to 0.921, and providing innovative concepts for future catalyst design.

Interzeolite Transformation through Cross-Nucleation: A Molecular Mechanism for Seed-Assisted Synthesis.

Polymorph selection and efficient crystallization are central goals in zeolite synthesis. Crystalline seeds are used for both purposes. While it has been proposed that zeolite seeds induce interzeolite transformation by dissolving into structural units that promote nucleation of the daughter crystal, the seed's structural elements do not always match those of the target zeolite. This discrepancy raises the question of how the seed promotes the daughter phase. Here, we present the first molecularly resolved investigation of seed-assisted zeolite synthesis. Using molecular simulations, we reproduce the experimental finding that a parent zeolite can promote the nucleation of a daughter zeolite even when it lacks common composite building units (CBUs) or crystal planes. Modeling the seed-assisted synthesis of an AFI-type zeolite using zeolite CHA, our simulations indicate that stand-alone CBUs from the parent seed do not facilitate daughter crystal formation. However, introducing the intact seed significantly reduces the synthesis time, supporting that seed integrity is key to increased efficiency. This reduction arises from the cross-nucleation of the AFI-type zeolite on the CHA (001) face. We find that parent and daughter zeolites are connected by an interfacial transition layer with an order distinct from that of both zeolites. Simulations reveal that cross-nucleation occurs over a broad range of synthesis conditions. We argue that cross-nucleation would be most favorable for zeolite pairs that share crystalline planes such as those forming intergrowths. Our findings suggest that the prevalence of intergrowths with a common lattice plane in zeolite synthesis is likely a kinetic effect of accelerated cross-nucleation.