Intrinsic Structural Properties Research Articles

CHIMERA_NA: A Customizable Mutagenesis Tool for Structural Manipulations in Nucleic Acids and Their Complexes.

Studying the structure and dynamics of nucleic acids and their complexes is crucial for understanding fundamental biological processes and developing therapeutic interventions. However, the limited availability of experimentally characterized nucleic acid structures poses a challenge for exploring their properties comprehensively. To address this, we developed a customizable mutagenesis tool, CHIMERA_NA, to manipulate nucleic acid structures and their complexes. Utilizing the user-friendly CHIMERA_NA, researchers can perform mutations in nucleic acid structures, enabling the exploration of diverse structural configurations and dynamic behaviors. The tool offers the flexibility to generate all possible combinations of mutations or specific user-defined mutations based on research requirements. CHIMERA_NA leverages the capabilities of UCSF Chimera software, a widely used platform for molecular structure analysis, to facilitate the generation of mutations in nucleic acids. Our tool modifies the reference structure of nucleic acids or their complexes to generate initial coordinates of mutated structures/complexes within seconds for further computational exploration. This capability allows users to extend their investigations beyond structural repositories, enabling the study of DNA/RNA drug recognition, nucleic acid-protein interactions, and the intrinsic structural and dynamic properties of nucleic acids. By providing a user-friendly and customizable approach to nucleic acid mutagenesis, CHIMERA_NA contributes to advancing our understanding of nucleic acid biology and facilitating drug discovery efforts targeting nucleic acid-based mechanisms. CHIMERA_NA is freely available in the Supporting Information of this article.

The Changing of Micromechanical Properties of Coal after Water Immersion: The Insight from Nanoindentation Test

The application of the hydrodynamic method has enhanced the extraction of coal bed methane (CBM). In this method, fracturing fluid rapidly penetrates the coal reservoir, altering its intrinsic pore structure and microscopic mechanical properties. These changes impact the properties of the coal reservoir and CBM depletion. It is, therefore, crucial to explore how these micro-characteristics evolve following water invasion. In this context, using nanoindentation tests, the microscopic characteristics of three coal samples were measured under dry conditions and at water saturations corresponding to 44% and 75% relative humidity. The influence of water immersion on the pore structure was also assessed using mercury injection experiments. Moreover, cluster analysis was used to categorize the extensive measured data into three sub-components: fractures (large pores), inertinite, and vitrinite, to investigate the impact of water saturation on microscopic properties. The findings indicate that cluster analysis is well-suited to these data, showing excellent agreement with porosity and maceral tests. The relationship between the elastic modulus and hardness of dry and wet coal samples varies across the sub-components. There is a notable dependency in the case of vitrinite, whereas water content tends to reduce this dependency. It is also found that water content negatively affects elastic modulus and hardness and reduces the anisotropy ratio. The mechanical properties of inertinite are highly responsive to water immersion, whereas vitrinite exhibits lesser sensitivity. The softening mechanisms of coal when immersed in water, such as calcite phase dissolution, swelling stress fracturing, and weakening of macerals, are identified. This study offers new perspectives on the impact of moisture on the alteration of micromechanical properties in coal.

Supramolecular assembled macroscopic soft scaffolds of thioindigo amphiphiles as cell-material interfaces

Biocompatible synthetic supramolecular systems have been proven success in fabricating regenerative biomedical materials with intrinsic functionality, tunability, and stimuli-responsiveness. However, it remains highly challenging to develop a supramolecular soft scaffold that allows transferring intrinsic microscopic aligned structural properties to cell attachments. Herein, we report a thioindigo bola-amphiphile (TIA) that is equipped with long alkyl-linker to connect the carboxylic acid end-group on the opposite side. Though photoresponsiveness of TIA is hindered in aqueous medium, it can be slightly improved by utilizing a co-solvent system or doping TIA with other amphiphiles. Electron microscopies and X-ray diffraction analysis suggest that a large aspect ratio of TIA nanostructures assembled into macroscopic soft scaffold with high degree of unidirectional alignment. The fabricated TIA macroscopic soft scaffold is further incubated with hMSCs, in revealing unidirectional aligned cell attachments. This work could provide an alternative strategy towards development of next-generation biocompatible soft functional materials.

Oxidized structure and Compositional properties of 1144 phase FBS by analytical electron microscopy

The 1144 phase (Ae1A1Fe4As4) shows a strong advantage of engineering fabrication among Fe (Iron)-based superconductor (FBS) family due to the robustness of its superconducting properties with respect to chemical inhomogeneities, granted by its uniform crystalline-layered structure. This regularity is furthermore associated to crystalline defects capable of acting as efficient pinning centers, from which high critical currents can achieved at high fields. Like other FBS phases, its lossless current-carrying capability can be remarkably degraded by distractions at grain boundaries (GBs). GB oxidation is an issue of upmost importance to the realization of the practical FBS application for high field (> 20T) magnet. In this study, we explore oxidized grain boundary and intrinsic grain structural properties of 1144 polycrystalline samples by applying analytical electron microscopy such as atomic resolution scanning transmission electron microscopy and atom probe tomography. These structural properties of samples produced by a mechanochemically assisted synthesis are evaluated following the degradation of superconducting properties due to oxidation. We observe a strong correlation between the contamination at grain boundaries and the decrease of transport properties of the bulk sample, while the crystallin structure seems to be not affected by the oxidation.

A mini Review on Analytical and Bioanlytical Techniques in Study of Drugs-Protein Interaction

The choice of a suitable analytical technique for the identification of a drug or a combination of drug mainly depends on the sample matrix complexity and the analyte concentration. The appropriate choice of an analytical method is based on properties of studied analyte such as intrinsic structure and physicochemical properties etc. The extensive development of the pharmaceutical field requires more meticulous analytical methods for the control of various diseases by means of drugs. The aim of this review article was to study the drug protein interaction with respect to various analytical methods which are applied in research and innovative field of Pharmacy. The crucial factor involved and affects the binding of drugs with Body protein is distribution as well as bioactivity of drugs in the body. In biological science and medicine, the quantitative analysis of protein in biological liquids is of great importance. The aim of the review was therefore to summarize all available examples and information about the use of current analytical applications on various categories of drugs in their dosage forms and in biological samples. The different pharmaceutical active compounds, which have been determined using different methods, are summarized for the future reference of researcher.

Pyrolysis-Free Covalent Organic Polymers Directly for Oxygen Electrocatalysis.

ConspectusOxygen electrode catalysis is crucial for the efficient operation of clean energy devices, such as proton exchange membrane fuel cells (PEMFCs) and Zn-air batteries (ZABs). However, sluggish oxygen electrocatalysis kinetics in these infrastructures put forward impending requirements toward seeking efficient oxygen-electrode catalytic materials with a clear active-site configuration and geometrical morphology to study in depth the structure-property relationship of materials. Although transition-metal-nitrogen-carbon (M-N-C) electrocatalysts have shown great prospects currently and potential in oxygen electrocatalysis as promising platinum group metal-free catalysts, the universal pyrolysis operation in the preparation process often inevitably brings about randomness and diversity of active sites, for which it is difficult to determine the structure-activity relationship, understand the catalytic mechanism, and further improve facilities performance.Covalent organic polymers (COPs) are a class of molecular geometric constructs linked by irreversible kinetic covalent bonds through reticular chemistry. Unique structural tailorability, diverse design principles, and inherent well-defined construction in pristine COPs naturally provide a great platform to study the structure-property relationship of active sites and exhibit unique features for application. In this Account, we afford an overview of our recent attempts toward the utilization of COP materials as free-pyrolysis oxygen electrode catalysts, enabling accurate construction of oxygen electrodes with clear active site and geometrical morphology characteristics in PEMFC and ZAB devices yet without enduring any high-temperature pyrolysis treatments. Starting from the needs of modern electrocatalysis, we discussed the unique properties for the design and development of pyrolysis-free pristine COPs as high-performance oxygen electrode catalytic materials in terms of intrinsic electronic structure properties and membrane-electrode-assembly (MEA) application distinguished from pyrolysis M-N-C catalysts. First, the pyrolysis-free COP catalysts provide a viable molecular model catalyst platform, which is conducive to mechanism comprehension for the relationship between catalyst activity and structure. Second, the simple and low-energy consumption synthesis process for pyrolysis-free catalysts lays the foundation for the large-scale production of catalysts, oxygen electrodes, and even the entire stack assembly without considering numerous complicated factors as traditional pyrolytic catalysts. Besides, most traditional COPs are difficult to dissolve and solution process due to their cross-linked skeleton. Our newly developed COP materials with solution processability bring about new opportunities to the process and assemble oxygen electrodes into device. These properties are unparalleled and have not been systematically reviewed and analyzed by any research reports so far. Here, we have clarified the specific advantage and potential of pyrolysis-free COP materials as oxygen electrodes applied in PEMFC and ZAB devices in response to the latest progress and requirements of current electrocatalytic research.

A brief review on systematic approach to polymer selection for development of capillary/hollow-fibre membrane for practical applications

Polymeric membranes are widely used for treatment of lean stream in chemical process industries. These membranes are used in different configurations such as tubular, plate & frame, disc-tube, spiral and capillary/hollow-fibre. Membrane modules with capillary/hollow-fibre configuration appears promising in ultrafiltration applications due to its relatively higher packing density, ease of backwashing, ease of cleaning and lower pressure drops since it can be operated at laminar flow regime with high cross-flow velocity. Hence, efforts are being made by researchers to make capillary/hollow-fibre membrane modules from various polymers, ranging from most hydrophilic polyacrylonitrile (PAN) to super-hydrophobic polypropylene (PP) and polytetrafluorethylene (PTFE). Here, we discuss the qualifying properties of the polymeric materials suitable to spin into capillary/hollow-fibre ultrafiltration membranes. Selection of polymers for making fibres requires in-depth knowledge of properties of base polymer and its processability/fabricability. The important properties to be considered for making capillary/hollow-fibre membrane are intrinsic structural properties of the base polymer like degree of crystallinity, tensile strength, tensile modulus, etc. The functional properties such as permeability, hydrophilicity/hydrophobicity etc. also plays role in selecting polymer for a given application. The polymer should also have appreciable dissolution in available solvents or should have degradation temperature higher than melting point so that it can be processed through appropriate membrane preparation process.

Structure of pre-miR-31 reveals an active role in Dicer–TRBP complex processing

As an essential posttranscriptional regulator of gene expression, microRNA (miRNA) levels must be strictly maintained. The biogenesis of many miRNAs is mediated by trans-acting protein partners through a variety of mechanisms, including remodeling of the RNA structure. miR-31 functions as an oncogene in numerous cancers, and interestingly, its biogenesis is not known to be regulated by protein-binding partners. Therefore, the intrinsic structural properties of the precursor element of miR-31 (pre-miR-31) can provide a mechanism by which its biogenesis is regulated. We determined the solution structure of pre-miR-31 to investigate the role of distinct structural elements in regulating processing by the Dicer-TRBP complex. We found that the presence or absence of mismatches within the helical stem does not strongly influence Dicer-TRBP processing of the pre-miRNAs. However, both the apical loop size and structure at the Dicing site are key elements for discrimination by the Dicer-TRBP complex. Interestingly, our NMR-derived structure reveals the presence of a triplet of base pairs that link the Dicer cleavage site and the apical loop. Mutational analysis in this region suggests that the stability of the junction region strongly influences processing by the Dicer-TRBP complex. Our results enrich our understanding of the active role that RNA structure plays in regulating miRNA biogenesis, which has direct implications for the control of gene expression.

Conceptual Approaches to Robustness Assessment of Building Structures, Buildings and Facilities

Some examples of failures of structures, buildings, where the lack of robustness was recognized, are analyzed. Several author’s definitions for robustness are presented and discussed. Special emphasis is given to the fact that define robustness as an intrinsic structural property and the other hand it as a property of the structure and its environment. Some related concepts are presented and discussed.The most important proposed measures for robustness are also present-ed including some illustration examples. Finally, a comparison between them is made and the respective shortcomings are identified. After anal-ysis of the robustness nature, a new structural oriented definition is pro-posed. Based on the highlighted shortcomings of the existing measures, in particular those related with the application to deteriorated structures, a conceptual framework for robustness assessment is proposed.

Spectroscopic Insight into Customized Iodine Ligands Passivated Red‐Emitting CsPb(Br,I)3 Perovskite Nanocrystals via Time‐Resolved Photoluminescence

AbstractMolecular engineering toward the structure of a passivation ligand is essential to improve the photoluminescence (PL) efficiency of perovskite nanocrystals (PNCs). To establish the surface recovery mechanism of red‐emitting CsPb(Br,I)3 NCs with PbI2 additives in the presence of a tightly bound passivation layer, time‐resolved photoluminescence (TRPL) measurements and their chemometric analysis are employed. Two quaternary alkylammonium ligands, didodecyldimethylammonium iodide (DDAI) and tridodecylmethylammonium iodide (TDAI), are used to form a passivation layer, and then their role in the surface defects recovery is investigated by varying the amount of PbI2 additives. It is found that the structural difference between DDAI and TDAI can affect the accessibility of PbI2 additives to surface defects. The TRPL spectra analysis reveals that the ligand passivation with DDAI does not induce discernible lifetime enhancement with using PbI2 additives, but only a non‐radiative pathway is gradually accelerated with increasing the amount of them. The TDAI ligand, however, shows the opposite behavior to give the best PL performance with a distinct molar ratio of TDAI:PbI2, even though the passivation itself gives a lower PL performance. It is argued that the intrinsic structural properties of the TDAI ligand are responsible for the effective surface recovery with the additives.

DREAM: an R package for druggability evaluation of human complex diseases.

De novo drug development is a long and expensive process that poses significant challenges from the design to the preclinical testing, making the introduction into the market slow and difficult. This limitation paved the way to the development of drug repurposing, which consists in the re-usage of already approved drugs, developed for other therapeutic indications. Although several efforts have been carried out in the last decade in order to achieve clinically relevant drug repurposing predictions, the amount of repurposed drugs that have been employed in actual pharmacological therapies is still limited. On one hand, mechanistic approaches, including profile-based and network-based methods, exploit the wealth of data about drug sensitivity and perturbational profiles as well as disease transcriptomics profiles. On the other hand, chemocentric approaches, including structure-based methods, take into consideration the intrinsic structural properties of the drugs and their molecular targets. The poor integration between mechanistic and chemocentric approaches is one of the main limiting factors behind the poor translatability of drug repurposing predictions into the clinics. In this work, we introduce DREAM, an R package aimed to integrate mechanistic and chemocentric approaches in a unified computational workflow. DREAM is devoted to the druggability evaluation of pathological conditions of interest, leveraging robust drug repurposing predictions. In addition, the user can derive optimized sets of drugs putatively suitable for combination therapy. In order to show the functionalities of the DREAM package, we report a case study on atopic dermatitis. DREAM is freely available at https://github.com/fhaive/dream. The docker image of DREAM is available at: https://hub.docker.com/r/fhaive/dream.

Dependence of lithium metal battery performances on inherent separator porous structure regulation

Boosting of rechargeable lithium metal batteries (LMBs) holds challenges because of lithium dendrites germination and high-reactive surface feature. Separators may experience structure-determined chemical deterioration and worsen Li plating-stripping behaviors when smoothly shifting from lithium-ion batteries (LIBs) to LMBs. This study precisely regulations the crystal structure of β-polypropylene and separator porous construction to investigate the intrinsic porous structure and mechanical properties determined electrochemical performances and cycling durability of LMBs. Crystal structure characterizations, porous structure analyses, and electrochemical cycling tests uncover appropriate annealing thermal stimulation concentrates β-lamellae thickness and enhances lamellae thermal stability by rearranging molecular chain in inferior β-lamellae, maximally homogenizing biaxial tensile deformation and resultant porous constructions. These even pores with high connectivity lower ion migration barriers, alleviate heterogeneous Li+ flux dispersion, stabilize reversible Li plating-stripping behaviors, and hinder coursing and branching of Li dendrites, endowing steady cell cycling durability, especially at higher currents due to the highlighted uncontrollable cumulation of dead Li, which offers new insights for the current pursuit of high-power density battery and fast charging technology. The suggested separator structure-chemical nature functions in ensuring cyclic cell stability and builds reliable relationships between separator structure design and practical LMBs applications.

OPA1 Dominant Optic Atrophy: Pathogenesis and Therapeutic Targets.

OPA1 Dominant Optic Atrophy: Pathogenesis and Therapeutic Targets.

Bismuth-Based Metal Clusters─From Molecular Aesthetics to Contemporary Materials Science.

ConspectusBismuth-based research has become a highly topical field in recent years, yielding remarkable prospects for new fundamental insights and new materials applications, ranging from innovative catalysts to novel pharmaceuticals, due to this heavy metal's virtually nonradioactive and nontoxic properties. Given that the 6s2 electron pair can be stereochemically active under certain circumstances, bismuth atoms adopt a variety of coordination modes and bonding environments with oxidation states ranging from (formally) +V to -III. As a consequence, bismuth-based compounds cover the entire spectrum from simple coordination compounds to much more unusual cluster cations and cluster anions exhibiting metal-metal bonding in a homoatomic manner, or in concert with other s-, d-, p-, or f-block metal atoms. Such bismuth clusters show high potential for the development of new bismuth-based materials, but they are also interesting objects by themselves. Given the relatively recent development of bismuth-rich cluster molecules, a deep understanding of their properties─including unprecedented structural features, complex electronic structures, substantial heavy metal aromaticity, as well as their formation pathways─is still in its infancy. The topic thus spans a broad range from highly sophisticated synthetic chemistry through interdisciplinary experimental and theoretical analyses to materials science.Based on our recent work and several notable reports from other groups, this article will highlight the successful access to a number of novel bismuth-rich cluster ions emerging from both solution-based approaches and solid-state chemistry. It will shed light on the unique structural and electronic properties that cause chemical and physical peculiarities of such compounds. Selected examples include, but are not limited to, (1) the first encapsulation of actinide ions in intermetalloid clusters which additionally served to manifest substantial all-metal π-aromaticity with a (calculated) record ring current per electron; (2) a large metalloid {Zn12} unit stabilized in a porphine-related {Zn8Bi16} moiety in [K2Zn20Bi16]6-; (3) the largest assembly of bismuth atoms within one molecule, observed in [{Ru(cod)}4Bi18]4- that consists of two Bi-Bi-linked "[{Ru(cod)}2Bi9]2-" subunits.Notably, cluster growth has remained largely a black box, which is starting to be revealed, however. We discuss possible formation pathways of such (multi)metallic nanoarchitectures on the basis of smaller subunits that were detected by mass spectrometric analyses and could also be captured upon reaction with organometallic complexes. In addition to the intrinsic structural and electronic properties of the cluster anions and cluster cations reviewed herein, we will briefly introduce the emerging usage of bismuth-based compounds in material science and give an outlook to future developments.

BIOMIMETIC HEMATOMA: NOVEL CARRIER DELIVERS EXTREMELY LOW-DOSE RHBMP-2 FOR HIGHLY EFFECTIVE HEALING OF LARGE BONE DEFECTS IN GOATS

Our previous rat study demonstrated an ex vivo-created “Biomimetic Hematoma” (BH) that mimics the intrinsic structural properties of normal fracture hematoma, consistently and efficiently enhanced the healing of large bone defects at extremely low doses of rhBMP-2 (0.33 μg). The aim of this study was to determine if an extremely low dose of rhBMP-2 delivered within BH can efficiently heal large bone defects in goats.Goat 2.5 cm tibial defects were stabilized with circular fixators, and divided into groups (n=2-3): 2.1 mg rhBMP-2 delivered on an absorbable collagen sponge (ACS); 52.5 μg rhBMP-2 delivered within BH; and an empty group. BH was created using autologous blood with a mixture of calcium and thrombin at specific concentrations. Healing was monitored with X-rays. After 8 weeks, femurs were assessed using microCT.Using 2.1 mg on ACS was sufficient to heal 2.5 cm bone defects. Empty defects resulted in a nonunion after 8 weeks. Radiographic evaluation showed earlier and more robust callus formation with 97.5 % (52.5 μg) less of rhBMP-2 delivered within the BH, and all tibias were fully bridged at 3 weeks. The bone mineral density was significantly higher in defects treated with BH than with ACS. Defects in the BH group had smaller amounts of intramedullary and cortical trabeculation compared to the ACS group, indicating advanced remodeling.The results confirm that the delivery of rhBMP-2 within the BH was much more efficient than on an ACS. Not only did the large bone defects heal consistently with a 40x lower dose of rhBMP-2, but the quality of the defect regeneration was also superior in the BH group. These findings should significantly influence how rhBMP-2 is delivered clinically to maximize the regenerative capacity of bone healing while minimizing the dose required, thereby reducing the risk of adverse effects.

Intrinsic Formamidinium Tin Iodide Nanocrystals by Suppressing the Sn(IV) Impurities.

The long search for nontoxic alternatives to lead halide perovskites (LHPs) has shown that some compelling properties of LHPs, such as low effective masses of carriers, can only be attained in their closest Sn(II) and Ge(II) analogues, despite their tendency toward oxidation. Judicious choice of chemistry allowed formamidinium tin iodide (FASnI3) to reach a power conversion efficiency of 14.81% in photovoltaic devices. This progress motivated us to develop a synthesis of colloidal FASnI3 NCs with a concentration of Sn(IV) reduced to an insignificant level and to probe their intrinsic structural and optical properties. Intrinsic FASnI3 NCs exhibit unusually low absorption coefficients of 4 × 103 cm-1 at the first excitonic transition, a 190 meV increase of the band gap as compared to the bulk material, and a lack of excitonic resonances. These features are attributed to a highly disordered lattice, distinct from the bulk FASnI3 as supported by structural characterizations and first-principles calculations.

Molybdenum carbide MXene embedded with nickel sulfide clusters as an efficient electrocatalyst for hydrogen evolution reaction

Molybdenum-based MXene materials (Mo2CTx) have recently demonstrated great potential in electrocatalytic hydrogen production. Herein, we fabricated a novel NiS/Mo2CTx hybrid via chemical etching in an NH4F/HCl solution followed by solvothermal reactions, where nickel sulfide (NiS) clusters were embedded between the interlayers of Mo2CTx. The intrinsic structure and electrochemical properties were experimentally investigated to explore the potential of an electrocatalyst for hydrogen evolution. As expected, the heterostructure by embedding NiS into the Mo2CTx MXene interlayers not only brings about large electrochemical surface areas with abundant active site exposure but also enhances the intrinsic kinetics to facilitate the electrolysis process. Electrochemical tests revealed that the NiS/Mo2CTx catalyst exhibited the HER performance with a small overpotential of 157 mV to drive the current density of 10 mA cm−2 and long-term stable durability, which are superior to that of pristine Mo2CTx MXene and nickel sulfides. This study can provide a synthetic strategy for designing and developing Mo2CTx MXene-based electrocatalysts for hydrogen production.

On the Single-Molecule Magnetic Behavior of Linear Iron(I) Arylsilylamides.

The rational design of 3d-metal-based single-molecule magnets (SMM) requires a fundamental understanding of their intrinsic electronic and structural properties and how they translate into experimentally observable features. Here, we determined the magnetic properties of the linear iron(I) silylamides K{crypt}[FeL2] and [KFeL2] (L = -N(Dipp)SiMe3; crypt = 4,7,13,16,21,24-Hexaoxa-1,10-diazabicyclo[8.8.8]hexacosan). For the former, slow-relaxation of the magnetization with a spin reversal barrier of Ueff = 152 cm-1 as well as a closed-waist magnetic hysteresis and magnetic blocking below 2.5 K are observed. For the more linear [KFeL2], in which the potassium cation is encapsulated by the aryl substituents of the amide ligands, the relaxation barrier and the blocking temperature increase to Ueff = 184 cm-1 and TB = 4.5 K, respectively. The increase is rationalized by a more pronounced axial anisotropy in [KFeL2] determined by dc-SQUID magnetometry. The effective relaxation barrier of [KFeL2] is in agreement with the energy spacing between the ground and first-excited magnetic states, as obtained by field-dependent IR-spectroscopy (178 cm-1), magnetic measurements (208 cm-1), as well as theoretical analysis (212 cm-1). In comparison with the literature, the results show that magnetic coercivity in linear iron(I) silylamides is driven by the degree of linearity in conjunction with steric encumbrance, whereas the ligand symmetry is a marginal factor.

Generalizable Descriptors of Highly Sensitive Detection of As(III) over Transition-Metal Single Atoms: A Combined Density Function Theory and Gradient Boosting Regression Approach.

Traditional nanomodified electrodes have made great achievements in electrochemical stripping voltammetry of sensing materials for As(III) detection. Moreover, the intermediate states are complicated to probe because of the ultrashort lifetime and complex reaction conditions of the electron transfer process in electroanalysis, which seriously hinder the identification of the actual active site. Herein, the intrinsic interaction of highly sensitive analytical behavior of nanomaterials is elucidated from the perspective of electronic structure through density functional theory (DFT) and gradient boosting regression (GBR). It is revealed that the atomic radius, d-band center (εd), and the largest coordinative TM-N bond length play a crucial role in regulating the arsenic reduction reaction (ARR) performance by the established ARR process for 27 sets of transition-metal single atoms supported on N-doped graphene. Furthermore, the database composed of filtered intrinsic electronic structural properties and the calculated descriptors of the central metal atom in TM-N4-Gra were also successfully extended to oxygen evolution reaction (OER) systems, which effectively verified the reliability of the whole approach. Generally, a multistep workflow is developed through GBR models combined with DFT for valid screening of sensing materials, which will effectively upgrade the traditional trial-and-error mode for electrochemical interface designing.

Carbon-supported CoS4-C single-atom nanozyme for dramatic improvement in CO2 electroreduction to HCOOH: A DFT study combined with hybrid solvation model

Single-atom nanozymes (SANs) have attracted extensive attention due to their characteristics of both single-atom catalysts (SACs) and enzymes. Using spin-polarized density functional theory (DFT) calculations combined with the hybrid solvation model, this work designed a series of carbon-supported Group VIII transition metals TMS4-C SANs, similar to the TMS4 active center of formate dehydrogenase (FADH), aiming to develop highly efficient SANs for CO2 electroreduction. DFT calculations show that compared with TMN4-C, TMS4-C have FADH-like feature, which can selectively reduce CO2 to formic acid. Particularly, CoS4-C is the most promising SAN for CO2 reduction, with a low limiting potential of -0.07 V, which exceeds most reported catalysts. Two descriptors of TMX4-C (X = N, S) based on intrinsic and electronic structure properties were proposed to shed light on the origin activity of candidates. The findings presented here will provide new insights into the design of novel enzyme-like catalysts for electrochemical CO2 reduction.