Complete Splitting Research Articles

Unveiling the Electrocatalytic Activity of Bifunctional Iron‐Niobium Double Perovskites for Overall Water Splitting: A‐Site Cation Influence

AbstractCapitalizing on the electrochemical conversion of water into hydrogen stands as a pivotal strategy in the global transition toward sustainable energy sources. This study investigates the influence of the A‐site cation type within A2FeNbO6 double perovskites (where A = Ca, Sr, or Ba) on their bifunctional electrocatalytic activities. The electrocatalytic performance is scrutinized in relation to charge transfer resistance, oxygen vacancy concentration, and metal‐oxygen covalency. Among the variants, Sr2FeNbO6 is distinguished as the optimal catalyst, achieving a current density of 10 mA cm⁻2 at overpotentials of 260 mV for the oxygen evolution reaction (OER) and 176 mV for the hydrogen evolution reaction (HER), thus matching the performance of leading metal oxide electrocatalysts. The study reveals pH‐dependent kinetics for Sr2FeNbO6, indicative of a lattice oxygen evolution mechanism for OER. An electrolyzer employing Sr2FeNbO6 electrodes for both the anode and cathode delivers a current density of 10 mA cm⁻2 at an efficient cell voltage of 1.76 V for complete alkaline water splitting, while also demonstrating exceptional stability. These insights advance the understanding of material optimization for electrocatalysis and position Sr2FeNbO6 as a viable catalyst for the sustainable production of hydrogen.

Breakdown of the molecular orbital picture for X-ray emission of water

By measuring X-ray emission of the water molecule in liquid phase we establish a first example of K-shell X-ray emission spectra with strong breakdown of the molecular orbital picture. A complete splitting of the 2a1 peak into satellites is observed. A theoretical model with electronic configurations generated by coupled excitations/de-excitations, so-called semi-internal configuration interaction, captures the experimentally recorded features well. Differences with respect to the corresponding breakdown effect in ultraviolet photoelectron spectrum are highlighted. Molecular dynamics calculations indicate that solvent broadening can only make up for a small fraction of the width of the recorded 2a1 derived band.

Investigation of thermodynamical stability and generation of large half-metallic gap along with optical properties in N-doped YHfO3 (YHO) (Y = Ca, Sr, and Ba) perovskite materials by first principle calculations

Considerable energy gap (Eg) in insulating channel, high spin-filtering, significant mean free path, and high magnetic transition temperature (TC) escalate half-metallic (HM) ferromagnetic (FM) materials very enticing for spintronic applications. Herein, ab-initio calculations have been executed comprehensively to inquest the structural, thermodynamical, electronic, magnetic, and optical properties of pure as well as nitrogen (N)-doped YHfO3 (YHO) (Y = Ca/Sr/Ba) materials with one N atom added at one of the oxygen (O) site. First, the thermodynamical stability of both bulk and doped YHO systems has been examined by estimating the formation enthalpies (ΔHf) by Convex Hull analysis, which confirms the practical realization of these materials on experimental grounds. Moreover, mechanical stability of these systems is affirmed by estimating the necessary elastic constants and respective parameters. Strikingly, all doped systems possess complete (100%) splitting in spin↑ and spin↓ channels at Fermi level and depict HM FM character with significant Eg of 3.31, 3.49, and 3.24 eV in spin↓ channels for CaHO (CHO), SrHO (SHO), and BaHO (BHO) systems, respectively. It is also found that N 2p orbitals are totally responsible for the emergence of metatallicity and magnetic character in all these doped structures. Moreover, the ground state long range FM stability between two added N atoms in doped systems is affirmed by computing the difference of total energies of FM and anti-ferromagnetic (AFM) spin ordering (ΔE) along with estimated TC at different distances. Lastly, it is found that N-doped systems have a lower optical energy loss than pristine YHO systems in the incident photon energy range of 0-50 eV. Hence, the present study proposes that an unconventional doping approach with intrinsically non-magnetic element in a variety of YHO perovskite systems could be a useful method to alter their various physical properties and forecast their potential applications in the development of novel spintronic and optoelectronic devices.

Sorting of dynamical crystallization from dynamical fermionization: A quantum many-body approach

Dynamical fermionization refers to the phenomenon when the momentum distribution of impenetrable bosons asymptotically reaches that of non interacting fermions on sudden release from the trap. Whereas on sudden change in trap frequency results to Bose-Fermi oscillation which has been experimentally confirmed in the case of the Lieb-Liniger model in the Tonks-Girardeau (TG) regime. Crystallization happens for sufficiently strongly interacting repulsive bosons with dipolar interactions in one spatial dimension. Crystallization resembles fermionization but distinctly different due to long-range interaction. The present work aims to distinguish dynamical crystallization from dynamical fermionization in the expansion and breathing dynamics of N=4 strongly interacting bosons in TG limit. Our results suggest that the N-fold complete splitting in one-body density for dipolar bosons makes a clear signature of crystallization in the Bose-Fermi oscillation. We investigate the many-body dynamics by employing multiconfigurational time-dependent Hartree method for bosons which solve the N-body time-dependent Schrödinger equation numerically exactly.

Sulfurization of bimetallic (Co and Fe) oxide and alloy decorated on multi-walled carbon nanotubes as efficient bifunctional electrocatalyst for water splitting

The advancement in electrocatalysis, particularly in the development of efficient catalysts for hydrogen and oxygen evolution reactions (HER and OER), is crucial for sustainable energy generation through processes like overall water splitting. A notable bifunctional electrocatalyst, CoFe2O4/Co7Fe3, has been engineered to facilitate both OER and HER concurrently, aiming to reduce overpotentials. In the pursuit of further enhancing catalytic efficiency, a morphological transformation has been achieved by introducing a sulphur source and multi-walled carbon nanotubes (MWCNTs) into the catalyst system, resulting in S–CoFe2O4/Co7Fe3/MWCNTs. This modification has significantly improved the activity for both OER and HER. An onset overpotential of 250 mV@10 mAcm−2 for the OER and 270 mV@50 mAcm−2 for the HER, indicating efficient catalytic activity at relatively low overpotentials. S–CoFe2O4/Co7Fe3/MWCNTs display an outstanding long-term stability in alkaline electrolytes, with minimal Tafel slopes of 77 mV/dec for the OER and 70 mV/dec for the HER, suggesting sustained catalytic performance over extended periods. Furthermore, when employed as both the cathode and anode in the context of complete water splitting, S–CoFe2O4/Co7Fe3/MWCNTs demonstrate an impressive cell voltage of 1.52 V at a current density of 10 mA cm−2 in a 1 M KOH solution, showcasing its viability for practical applications. Given its cost-effectiveness and superior activity, S–CoFe2O4/Co7Fe3/MWCNTs hold significant promise for widespread applications in overall water splitting electrocatalysis, contributing to the advancement of cleaner and sustainable fuel generation technologies.

Mechanism of formation and evolution of bound states in the continuum of split-hole all-dielectric metasurface under asymmetric displacement perturbation

Bound states in the continuum (BICs) with ultra-high Q properties have attracted much attention for their perfect localization in the continuous spectral range coexisting with extended waves. In this study, breaking the traditional excitation form of structure breakage or excitation field asymmetry, a monolithic silicon nanodisk array with relative displacement generated by the complete splitting of square nanopores is proposed based on the unique electromagnetic properties of all-dielectric metamaterials. During the introduction of perturbations by asymmetric displacements of splitting holes, it is shown by numerical simulations that two BICs at different wavelengths can be realized. Combined with eigenmodes of group theory, the symmetric matching relationship between the symmetry-protected BICs and the free-space radiation during the evolution process is analytically demonstrated, and the formation mechanism and the evolution law of the BICs excited by this metasurface are deeply investigated. meanwhile, it also provides a theoretical basis for the polarization dependence of quasi-BICs excitation and the ultra-high Q factor expression of BICs. Furthermore, near-field distribution and multipole decomposition show that the field distribution and surface currents support the excitation of BIC-driven toroidal dipole and magnetic quadrupole dual modes. This study not only provides an effective reference for the stability of high-Q resonance wavelengths, but also solves the problem of the lack of universality in analyzing the resonance mechanism based on resonance phenomena, and provides solid theoretical support for the study of displacement-mediated BICs resonance excitation and evolution.

Hydrogen Sulfide Splitting into Hydrogen and Sulfur through Off-Field Electrocatalysis.

Hydrogen sulfide (H2S), a toxic gas abundant in natural gas fields and refineries, is currently being removed mainly via the Claus process. However, the emission of sulfur-containing pollutants is hard to be prevented and the hydrogen element is combined to water. Herein, we report an electron-mediated off-field electrocatalysis approach (OFEC) for complete splitting of H2S into H2 and S under ambient conditions. Fe(III)/Fe(II) and V(II)/V(III) redox mediators are used to fulfill the cycles for H2S oxidation and H2 production, respectively. Fe(III) effectively removes H2S with almost 100% conversion during its oxidation process. The H+ ions are reduced by V(II) on a nonprecious metal catalyst, tungsten carbide. The mediators are regenerated in an electrolyzer at a cell voltage of 1.05 V, close to the theoretical potential difference (1.02 V) between Fe(III)/Fe(II) and V(II)/V(III). In a laboratory bench-scale plant, the energy consumption for the production of H2 from H2S is estimated to be 2.8 kWh Nm-3 H2 using Fe(III)/Fe(II) and V(II)/V(III) mediators and further reduced to about 0.5 kWh Nm-3 H2 when employing well-designed heteropolyacid/quinone mediators. OFEC presents a cost-effective approach for the simultaneous production of H2 and elemental sulfur from H2S, along with the complete removal of H2S from industrial processes. It also provides a practical platform for electrochemical reactions involving solid precipitation and organic synthesis.

Analysis of the Possibility of Application of Deconstructive Strategy in Theological Studies

The article attempts to analyze the possibility of applying deconstructive strategy in theological research. For this purpose, the author firstly defines the specificity of the deconstructive strategy of thinking, which consists in the researcher’s aspiration to catch the trace left by the author in the original unwritten proto-text by means of revealing oppositions and their loosening, up to their complete splitting, contributing to the disclosure of new meanings in the text. Then, on the basis of the analysis of modern Russian studies concerning the critical comprehension of Jacques Derrida’s theory of deconstruction, a systematization of very contradictory remarks and objections is carried out, as a result of which three critically minded groups are revealed: researchers of Postmodernism and Poststructuralism, accusing deconstruction of debunking stable notions; the scholars of neo-Marxist direction, emphasizing its excessive Theology; theologians of various branches of Christian thought, revealing an atheological and even atheistic character in the deconstructive thinking strategy. The author of the paper further analyses the work of an Arabian scholar ‘Ali Zawwari Ahmad on the criticism of Arab modernists who use western deconstructive methodology in dealing with religious texts, thus revealing that in the contemporary Muslim world there are two opposing views on the use of deconstructive strategies in theological studies, which are according to the traditional Muslim community, faithfully defend the inviolability of religious traditions, including in the field of Theological Methodology.

Splitting of a droplet on a wettability-confined track driven by thermal marangoni effect

We investigate the dynamics of droplet splitting driven by the thermal Marangoni effect on a wettability-confined track based on the lubrication approximation. The results demonstrate that the restriction of the hydrophobic region and the driving of the eccentric heating prompt a droplet to split asymmetrically, and the complete splitting time under the eccentric heating is shortened compared to the concentric heating. Additionally, the time required for droplet splitting decreases with an increase in temperature gradient α and eccentric distance δ, while exhibiting an initial decrease and then an increase in variation with track width E, and the mass ratio M presents a positive correlation with α, δ, and E.

Impressive efficiency of zinc oxide-manganese oxide/MAX composite in two-electrode system for photovoltaic-electrolyzer water splitting

The improvement and use of affordable and efficient electrocatalysts for complete water splitting are crucial for the future of energy supply. Here, a hybrid zinc oxide (ZnO)–manganese oxide (Mn3O4)/Ti3AlC2 (MAX) composite produced by a facile hydrothermal synthesis is utilized as a dual-function electrocatalyst for the hydrogen and oxygen evolution reactions (HER and OER, respectively). Its well-organized surfaces and bulky porous framework provide numerous catalytically active sites during electrochemical reactions, leading to significant improvement in the HER and OER activities. In particular, the ZnO and Mn3O4 phases increase the catalytic activity of the electrode, while the MAX phase enhances the conductivity and promotes low overpotential Ni sites through charge transfer effects. Consequently, the optimized ZnO-Mn3O4/MAX/Ni foam electrode exhibits relatively low overpotentials (η) of 244 and 340 mV at 20 mA cm−2 for the HER and OER at 1.0 M KOH, respectively. The electrodes also demonstrate exceptional long-term stability during cycling for both the HER and OER. A fully homemade water splitter, using these electrodes as anode and cathode, achieves a current density of 10 mA cm−2 at a cell voltage of only 1.62 V. When integrated with commercially available silicon-based solar cells, combined PV-EC water splitting devices enable increased hydrogen generation from stimulated sunlight. This study presents a typical demonstrated and proven strategy for real large-scale solar hydrogen generation using cost-effective PV-EC technology.

Failure investigation of steel and brick aggregate concrete composite construction with angle and channel shear connectors

ABSTRACT This investigation focuses mainly on the failure behaviour and performance of angle and channel shear connectors in composite structures made with steel and brick aggregate concrete. It was observed that both angle and channel shear connectors did not fail themselves. However, in some specimens, localised connector yielding was observed in channel shear connectors. In both cases, concrete strata failed as either concrete crushing and shearing, combined splitting and bending, or complete splitting mode of failure. Crushing and shearing failure was noticed in specimens having smaller web and flange and were brittle in nature as compared to the failure of specimens with larger web and flange. Other parameters, such as shear resistance, energy absorption, and load-slip behaviour, were also investigated. Web height and flange width of both connectors significantly affected the ultimate shear capacity and slip of the brick aggregate concrete specimen. Channel connectors were found more flexible and carried more shear than angle connectors. Channel connectors had an average of 32.41% and 116.17% more ultimate load and slip capacity than the angle connectors in brick aggregate concrete, respectively. The load-carrying capacity, slip, and failure behaviour of the brick aggregate concrete were found similar to those of stone aggregate concrete.

Elucidating the performance of hexamethylene tetra-amine interlinked bimetallic NiCo-MOF for efficient electrochemical hydrogen and oxygen evolution.

Bimetallic metal-organic frameworks (MOFs) play a significant role in the electrocatalysis of water due to their large surface area and availability of increased numbers of pores. For the inaugural time, we examine the effectiveness of a hexamethylene tetra-amine (HMT)-induced 3D NiCo-MOF-based nanostructure as a potent bifunctional electrocatalyst with superior performance for overall water splitting in alkaline environments. The structural, morphological, and electrochemical properties of the as-synthesized bifunctional catalyst were examined thoroughly before analyzing its behavior towards electrochemical water splitting. The HMT-based NiCo-MOF demonstrated small overpotential values of 274 mV and 330 mV in reaching a maximum current density of 30 mA cm-2 for hydrogen and oxygen evolution mechanisms, respectively. The Tafel parameter also showed favorable HER/OER reaction kinetics, with slopes of 78 mV dec-1 and 86 mV dec-1 determined during the electrochemical evaluation. Remarkably, the NiCo-HMT electrode exhibited a double-layer capacitance of 4 mF cm-2 for hydrogen evolution and 23 mF cm-2 for oxygen evolution, while maintaining remarkable stability even after continuous operation for 20 hours. This research offers a valuable blueprint for implementing a cost-effective and durable MOF-based bifunctional catalytic system that has proven to be effective for complete water splitting. Decomposition of water under higher current densities is crucial for effective long-term generation and commercial consumption of hydrogen.

Interlayer angle dependence of photoelectric properties of Sb/SnC van der Waals heterojunction and its application

The discovery of novel properties in a twisted bilayer graphene has opened up new avenues of research in physics and materials science, making the twistronics a new research hotspot. In this paper, based on two-dimensional tin-based materials and antimonene monolayers, six types of Sb/SnC two-dimensional van der Waals heterostructures (vdWH) with different interlayer twist angles are constructed, and their optoelectronic properties and applications are studied by First-principles calculations. All modeling and calculations are performed using the density functional theory (DFT) software Quantum-ATK. The results show that the Sb/SnC vdWHs with six different interlayer twist angles have various band gaps, and when the interlayer twist angles are 10.89°, 19.11°, 23.41°, and 30°, the Sb/SnC vdWH exhibit a type-I band edge alignment, while at 8.95° and 13.59°, they present a type-II band structure. Results of the orbital-projected band structures of the Sb/SnC vdWHs reveals that the change in interlayer twist angles alters the atomic stacking in the heterostructures, thereby modifying orbital coupling and further tuning the electronic structure of the heterostructures. Additionally, the calculated absorption spectra indicate that compared with individual Sb and SnC monolayers, the absorption coefficient of the Sb/SnC vdWHs in the visible light region was significantly enhanced, and the optical absorption characteristics of the heterostructures with different interlayer twist angles varied markedly. In terms of applications, as materials for solar cells, the Sb/SnC vdWHs with interlayer twist angles of 8.95° and 13.59° exhibit photovoltaic conversion efficiencies of 17.48% and 18.59%, respectively; as photocatalysts for the complete water splitting, the Sb/SnC vdWH with an interlayer twist angle of 8.95° could catalytically decompose water across a pH range of 0-2, while a twist angle of 13.59° confines its catalytic activity to pH values of 0 and 1. Therefore, Sb/SnC van der Waals heterostructures, with special rotation angles, hold promise for multifunctional applications in solar energy and photocatalysis fields. More importantly, our study demonstrates that in addition to conventional methods such as strain, doping, and defects, tuning the interlayer twist angle provides a new degree of freedom for manipulating the optoelectronic properties of materials.

“You Know There’s No ‘It’ Right? ‘It’ Was Just Us”

“You Know There’s No ‘It’ Right? ‘It’ Was Just Us”

A novel hierarchically hybrid structure of MXene and bi‐ligand ZIF‐67 based trifunctional electrocatalyst for zinc‐air battery and water splitting

AbstractThe development of cost‐effective and durable electrocatalysts possesses a broad spectrum of applications in sustainable energy systems. Herein, a hierarchical composite of Co‐based bi‐ligand zeolite imidazole framework (ZIF‐67) with highly conducting 2D MXene as highly efficient noble metal free electrocatalyst for electrochemical oxygen reduction reaction (ORR), complete water splitting, along with zinc‐air battery (ZAB) has been studied. ZIF‐67 is reported as an efficient electrocatalyst due to its porous structures, high surface area and atomically dispersed active metal centres while low conductivity and structural instability have been addressed by pyrolysis. In this work, structural disintegration due to temperature effect has been handled by using bi‐ligand linkers in ZIF (b‐ZIF‐67) which controls its sharp morphology and uniform mesoporous structure. This b‐ZIF‐67 has been supported on highly conducting 2D MXene material which exposes ample accessible active sites to accelerate the electroactivity of the synthesized catalyst. The resultant b‐CZIF‐67/MXene catalyst exhibits superior onset of 0.91 and 0.93 V in acidic and alkaline medium respectively for ORR. At the current density of 10 mA/cm2 catalyst shows a very low overpotential of 0.170 mV and 1.47 V for HER and OER, respectively. The excellent specific charge storage of 550.6 mAh/g was displayed by the homemade ZAB pouch.

Cross-sectional Imaging of Bifid Mandibular Condyle – A Rare Condition

Mandibular condyles constitute a major part of the temporomandibular joint. Bifid mandibular condyle (BMC) is a rare morphological variant of the condyle that is asymptomatic in most cases and can be diagnosed incidentally on a orthopantomogram during routine radiographic examination. But orthopantomography is a 2-dimensional imaging modality with various structures superimposed over the temporomandibular region causing practical difficulty in the diagnosis of BMC. The exact morphological architecture of the condyles can be more accurately visualized in advanced imaging techniques like computed tomography (CT) and cone beam computed tomography (CBMT), helping in the diagnosis of the bifid condyles. The radiological appearance of BMC varies depending on direction and depth of the separating groove. The typical radiographic presentation in most cases is a complete or incomplete split of the condylar heads, separated by a groove. This paper presents a case of a unilateral BMC on the right side which was diagnosed CBMT.

Tungsten Oxide-Based Z-Scheme for Visible Light-Driven Hydrogen Production from Water Splitting.

The stoichiometric water splitting using a solar-driven Z-scheme approach is an emerging field of interest to address the increasing renewable energy demand and environmental concerns. So far, the reported Z-scheme must comprise two populations of photocatalysts. In the present work, only tungsten oxides are used to construct a robust Z-scheme system for complete visible-driven water splitting in both neutral and alkaline solutions, where sodium tungsten oxide bronze (Na0.56WO3-x) is used as a H2 evolution photocatalyst and two-dimensional (2D) tungsten trioxide (WO3) nanosheets as an O2 evolution photocatalyst. This system efficiently produces H2 (14 μmol h-1) and O2 (6.9 μmol h-1) at an ideal molar ratio of 2:1 in an aqueous solution driven by light, resulting in a remarkably high apparent quantum yield of 6.06% at 420 nm under neutral conditions. This exceptional selective H2 and O2 production is due to the preferential adsorption of iodide (I-) on Na0.56WO3-x and iodate (IO3-) on WO3, which is evidenced by both experiments and density functional theory calculation. The present liquid Z-scheme in the presence of efficient shuttle molecules promises a separated H2 and O2 evolution by applying a dual-bed particle suspension system, thus a safe photochemical process.

The Effect of some Irrigation Methods and Moisture Depletion percent in the Growth and Productivity of Corn

The experiment was conducted in the fields of Al-Hilla - Babylon province, with loam soil, during the autumn season of 2021, to study the effect of different irrigation methods and levels of depletions on the growth and yield of corn (Zea mays L.). The Randomized Complete Block Design (RCBD) was an as complete split plot with three replications, the main plot included the treatment of depletion levels and subplot irrigation systems, and the treatments were distributed on the experimental plots randomly. Irrigation systems included three levels of subsurface drip irrigation - surface drip irrigation - surface irrigation with furrows, and the levels of depletion for each treatment were 20%, 40%, and 60%. The result showed that the subsurface drip irrigation treatment with 40% depletion achieved the highest plant height (206.92). While there was no significant difference with the surface drip treatment. The furrows irrigation system has the lowest plant height, which reached (174.14). There are significant differences between the treatment and the level of depletion in the area of the leaves of the plant. Also, the irrigation methods used did not significantly affect the weight and depth of the roots, while there were significant differences in the values ​​of yield weight for the treatments and water depletion rates.

Adiabatic light propagation in nonlinear waveguide couplers with longitudinally varying detunings via resonance-locked inverse engineering

We investigate the adiabatic evolution of light in nonlinear waveguide couplers via resonance-locked inverse engineering based on stimulated Raman adiabatic passage (STIRAP). The longitudinal varying detunings of the propagation coefficients are designed to eliminate dynamically the nonlinear effect, which induce the non-adiabatic oscillations. We show that different light evolutions such as complete light transfer, light split and light return can be realized adiabatically with appropriate choices of the detunings even in the nonlinear regime. The features open new opportunities for the realization of all-optical nonlinear devices with high fidelity in integrated optics.

Effect of Planting Dates on Yield and Its Components for Five Genotypes of Coarse Wheat, Triticum durum Desf L.

The experiment was conducted in the field at the Warka extension to the Agricultural Extension Service Department in the Ministry of Agriculture for the winter season 2022-2021 (north of Muthanna ), With a view to understanding how efficiently five newly introduced genotypes of coarse wheat and determining the best ones for the region’s conditions under the influence of different planting dates, The experiment was applied using Complete Block Design (R.C.B.D.) and Split Plot Design, along with three replications. the four dates for sowing (1/11, 10/11, 20/11 and 30/11) occupied the main plates, while the genotypes (G1133, G65 and G1105 and G1229 and the approved variety for comparison, Bohooth-7, Divided Plots. The findings indicated that the first meeting D1 (1/11) outperformed the number of spikes and the weight of one thousand grains with averages of (334.7 spikes/m2 and 49.99g), while the second date D2 (10/11) was superior in terms of spike count and grain weight, with averages of (50.00 grains, spike-1. and 13.92 tons.ha-1), while the third date D3 (20/11) exceeded the harvest index by (34.57%), While genotype G65 achieved the highest biological yield of 13.00 tons.ha-1, and genotype G1229 achieved the highest average number of spikes, which amounted to 3493 spikes.m-2, and genotype G1133 gave having the most grains per spike, which amounted to 50.97 grains. Spike-1, while the genotype gave Genetic G1105 The highest weight of a thousand grains was 43.93 g.