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In the past decade, natural orbital functional (NOF) approximations have emerged as prominent tools for characterizing electron correlation. Despite their effectiveness, these approaches, which rely on natural orbitals and their associated occupation numbers, often require hybridization with other methods to fully account for all correlation effects. Recently, a global NOF (GNOF) has been proposed [Piris, Phys. Rev. Lett. 127, 233001 (2021)] to comprehensively address both dynamic and static correlations. This study evaluates the performance of GNOF on strongly correlated model systems, including comparisons with highly accurate Full Configuration Interaction calculations for hydrogen atom clusters in one, two, and three dimensions. Additionally, the investigation extends to a BeH2 reaction, involving the insertion of a beryllium atom into a hydrogen molecule along a C2v pathway. According to the results obtained using GNOF, consistent behavior is observed across various correlation regions, encompassing a range of occupations and orbital schemes. Furthermore, distinctive features are identified when varying the dimensionality of the system. [ABSTRACT FROM AUTHOR]

In this work, the distribution and segregation behaviors of helium (He) and the effect of yttrium (Y) on these behaviors in the symmetrical tilt tungsten (W) Σ5(310)/[001] grain boundary (GB) region were studied using first-principles calculations. The results revealed that the GB has a significant impact on the behaviors of He in W. The solution and segregation energies of He in the W Σ5(310)/[001] GB region increase with increasing the distance from He to the GB and are inversely proportional to the effective electrons of He. The density of states analysis showed that the GB can suppress partial hybridization between He and W atoms. In addition, we find that the strengthening element Y facilitates the dissolution of He in the W GB region. [ABSTRACT FROM AUTHOR]

Endohedral metal–metal-bonding fullerenes have recently emerged, in which encapsulated metals form a metal–metal bond. However, the physical reasons why some metal elements prefer to form metal–metal bonds inside fullerene are still unclear. Herein, we reported first-principles calculations on electronic structures, bonding properties, dynamics, and thermodynamic stabilities of endohedral metallofullerenes M2@C82 (M = Sc, Y, La, Lu). Multiple bonding analysis approaches unambiguously reveal the existence of one two-center two-electron σ covalent metal–metal bond in M2@C82 (M = Sc, Y, Lu); however, the La–La bonding interaction in La2@C82 is weaker and could not be categorized as one metal–metal covalent bond. The energy decomposition analysis on bonding interactions between an encapsulated metal dimer and fullerene cages suggested that there exist two electron-sharing bonds between a metal dimer and fullerene cages. The reasons why La2 prefers to donate electrons to fullerene cages rather than form a standard σ covalent metal–metal bond are mainly attributed to two following facts: La2 has a lower ionization potential, while the hybridization of ns, (n − 1)d, and np atomic orbitals in La2 is higher. Ab initio molecular dynamic simulations reveal that the M–M bond length at room temperature follows the trend of Sc < Lu < Y. The statistical thermodynamics calculations at different temperatures reveal that the experimentally observed endohedral metal–metal-bonding fullerenes M2@C82 have high concentrations in the endohedral fullerene formation temperature range. [ABSTRACT FROM AUTHOR]

Terminal solid solutions in the Zn O 1 − x S e x system (0 ≤ x ≤ 0.15 , 0.95 ≤ x ≤ 1) exhibit extreme bandgap reduction attributable to band anti-crossing (BAC). In this work, we perform a theoretical investigation of alloying in this system (0 ≤ x ≤ 1). The temperature-composition phase diagram of Zn O 1 − x S e x is obtained via first principles and cluster expansion-based Monte–Carlo simulations. For 0 ≤ x ≤ 0.05 , a solid solution in the wurtzite structure and for 0.5 ≤ x ≤ 1 , a solid solution in the sphalerite structure is obtained. The alloy system exhibits a miscibility gap in the range of 0.05 ≤ x ≤ 0.5. Only the solid solutions are seen to obey bandgap reduction predicted by BAC. The bandgap of the alloys, calculated using the Δ -sol method, shows a bowing behavior as predicted by the BAC model. Difference in the electronegativities of O and Se atoms in the lattice leads to hybridization of O-2p and Se-4p electronic states. Interaction between these electronic states also leads to a split in the valence band edge at the O-rich end and a split in the conduction band edge at the Se-rich end. The effective mass, estimated from the density of states, of holes at the O-rich end and that of electrons at the Se-rich end, increases with alloying. These fundamental insights should help in choosing suitable alloy compositions for optimal photocurrent density when these materials are used as photoanodes. [ABSTRACT FROM AUTHOR]

In Janus photocatalysts, intrinsic dipole (P) plays an important role in the separation of photogenerated carriers and photocatalytic activity for water splitting. However, effectively switching the direction of the P vector between different surfaces is still an open issue. Based on first-principles calculation, we find that the P vector relies on charge distribution, while the distribution of the conduction band maximum-distributed reduction reaction surfaces (Sc) and valence band minimum-distributed oxidation surfaces (Sv) depends on the orbital hybridization in GaOI-based Janus. The direction of the P vector can be switched between Sc and Sv by substituting a metal or halogen atomic layer. The P vector in the direction from Sc to Sv releases bandgap limitation, broadens the light absorption range, and improves high carriers' mobility and solar-to-hydrogen efficiency (STH) efficiency, while the P vector pointing from Sv to Sc hinders the photocatalytic activity of GaOI-based Janus. Based on the investigation of STH efficiency and redox reactions, GaInOI is found to be a potential photocatalyst for overall water splitting. The stability of the Janus is studied by ab initio molecular dynamics and phonon diffusion spectrum. Current work proposes that switching the direction of the P vector between Sv and Sc is a potential route to regulate the band structure, optical absorption, and photocatalytic activity in GaOI-based Janus. [ABSTRACT FROM AUTHOR]

[Display omitted] The production of hydrogen through seawater electrolysis has recently garnered increasing concern. However, hydrogen evolution reaction (HER) by alkaline seawater electrocatalysis is severely impeded by the slow H 2 O adsorption and H* binding kinetics at industrial current densities. Herein, a face-centered cubic/hexagonal close packed (fcc/hcp) NiRu alloy heterojunction was fabricated on Ni foam (N doped NiRu-inf/NF) by a low-temperature nitrogen plasma activation. Simultaneously, nitrogen atoms are introduced into the alloy to facilitate d-p hybridization. When N doped NiRu-inf/NF is integrated into a dual-electrode cell for urea-assisted seawater electrolysis, it achieves 100 mA cm−2 with an ultra-low voltage of 1.36 V and excellent stability. Density functional theory (DFT) verifies that the robust d-p hybridization among Ni, Ru and N exhibits more energy level matching for H 2 O molecule adsorption at the Ru sites, while simultaneously reducing the interaction between H* and Ni sites in N -doped NiRu-inf. [ABSTRACT FROM AUTHOR]

Thermal rectification devices, which facilitate preferential heat flow in a singular direction, stands as pivotal tools in the realization of solid‐state thermal circuits. 1D atomic chains, exhibit heightened thermal rectification efficiency owing to their exceptional directional heat conduction properties. These will find widespread utility in many applications, encompassing areas such as cooling, energy harvesting, and thermal isolation systems. However, unlike quasi‐1D materials, the intrinsic anisotropic heat transport in true‐1D atomic chains is yet to be systematically studied. Herein, the origins of the anisotropic heat transfer in three representative 1D structures (TaSe3 and BaTiS3 marked as quasi‐1D, MoI3 labeled as true‐1D) is first investigated by integrating a first‐principles density functional theory‐based framework of two‐channel heat conduction model. In contrast to quasi‐1D, MoI3 exhibits a giant anisotropy of lattice thermal conductivity (κL) in chain‐ and cross chain‐directions with a high ratio up to ≈20, which far exceeds the previous report for HfTe5 and ZrTe5. Such unique heat transfer reveals comprehensively by charge‐sharing and transferred charges, p‐‐d orbital hybridization and Young's modulus changes, induces an exceptionally large anisotropy. This study presents a high‐performance implementation of thermal rectification designed to regulate directional heat current, demonstrating its potential applicability in solid‐state thermal circuits. [ABSTRACT FROM AUTHOR]

The main challenge in developing Schottky‐contact OER catalytic devices based on layered double hydroxides (LDHs) is to achieve metal–semiconductor junctions with low contact resistance and high charge transfer capacity. However, due to the presence of high potential barriers and Fermi pinning, conventional Schottky contacts are usually unsatisfactory, resulting in poor‐working electrode performance and high energy consumption. In this study, a new concept of “hindrance factor” is introduced to quantify the difficulty of electron transfer, and a low‐hindrance factor Schottky contact formed by strong coupling of semiconductor LDH and NiMo alloy clusters is designed. This interface guides charge redistribution, optimizes the bonding and orbital states of adsorption sites, and enhances the targeted adsorption of OH intermediates. The results show that the configured NiMo@NiFeCe‐LDH working electrode only needs 1.445 V (vs RHE) to drive the reaction and shows excellent durability in 400 h of testing. At the same time, based on this study, a strategy for screening high‐performance Schottky junctions is developed. This strategy provides a bridge for studying interface properties, orbital hybridization, and charge transfer, reveals the potential mechanism for reducing contact resistance, and has important guiding significance for screening high‐performance metal–semiconductor electrocatalysts and stability. [ABSTRACT FROM AUTHOR]

Although the ultrahigh theoretical energy density and cost‐effectiveness, lithium–sulfur (Li‐S) batteries suffer from sluggish conversion kinetics and the shuttling effect of soluble lithium polysulfides (LiPSs). Herein, conductive hexagonal cobalt‐organic framework (Co‐HTP) nanosheets are anchored in situ on carboxyl graphene (CG) substrates and serve as host catalysts to modulate the polysulfide redox. Substantial characterizations identify that the local coordination environment of the quadrilateral Co–N4 units transforms into an asymmetric penta‐coordinated O–Co–N4 with axial Co─O coordination, which triggers spin polarization and remarkable electron delocalization of Co 3d orbital. The higher spin state and lower local electron density of the O–Co–N4 sites induce more active electronic states in Co‐HTP/CG and facilitate orbital hybridization with polysulfides to form more stable bond orders. Such optimized electronic structure significantly accelerates redox kinetics and enhances the adsorption strength of polysulfides. These merit the lithium–sulfur battery based on Co‐HTP/CG with a high reversible capacity, impressive rate capability, and prolonged cycling performance over 500 cycles. This work will enrich the design philosophy of modulating the spintronic structure of electrocatalysts for advanced Li–S batteries and beyond. [ABSTRACT FROM AUTHOR]

The hybridization of MXene materials and transition metal dichalcogenides has a significant impact on heterojunction properties. The transport properties and electronic structure of heterojunctions of semiconducting MoS2 and metallic MXene Nb2C were studied by integrating density functional theory with non-equilibrium Green's function theory. The hybridization between Nb2C and MoS2 makes the tunneling barrier between the two layers disappear, which can enhance the electron injection efficiency from the Nb2C to the MoS2. Moreover, the Nb2C/MoS2 heterojunction exhibits a conventional n-type Schottky contact with a barrier height of 0.14 eV, which is significantly lower than the barrier height of 0.29 eV at the Ti/MoS2 junction. These factors result in a field-effect transistor with a low contact resistance of 138 Ω· μ m and a higher current of 1.09 mA μ m−1 at a bias voltage of 0.3 V applied between the left and right electrodes. Following the application of gate voltage, the I on/ I off ratio reaches 1266. [ABSTRACT FROM AUTHOR]

The manipulation of surface catalytic sites has rarely been explored for metal borides, and the subsurface effects on the electrocatalytic activity of the nitrogen reduction reaction (NRR) remain unknown. Herein, this work develops a core–shell nanoparticle catalyst with a Pd core that ensures high electron transfer rates and an Pd16B3 atomical shell that possess tunable active sites for regulating the NRR. The atomic structural evolution from Pd to Pd16B3 is investigated by precisely controlling the B atom diffusion, molecular rearrangement, and d–sp orbital hybridization. Pd/Pd16B3 core–shell nanocrystals exhibit an exceptional NRR performance with a high NH3 Faradaic efficiency of 30.8%, which is superior to those of pristine Pd (1.2%) and B‐doped Pd (4.8%) under identical conditions, and a yield rate of 0.81 µmol h−1 cm−2. This work discovers that the Pd16B3 shell could promote the NRR selectivity by separating the separating the hydrogen evolution reaction proceeded on hole sites and NRR proceeded on bridge sites, and the Pd core could provide the excellent conductivity to Pd16B3 shell through regulated electron interactions. Consequently, the controlled chemical ordering of palladium boride on palladium surfaces provides insight into the synthesis of advanced NRR electrocatalysts. [ABSTRACT FROM AUTHOR]

The heteroatom substitution is considered as a promising strategy for boosting the redox kinetics of transition metal compounds in hybrid supercapacitors (HSCs) although the dissimilar metal identification and essential mechanism that dominate the kinetics remain unclear. It is presented that d‐p orbital hybridization between the metal and electrolyte ions can be utilized as a descriptor for understanding the redox kinetics. Herein, a series of Co, Fe and Cu heteroatoms are respectively introduced into Ni3Se4 cathodes, among them, only the moderate Co‐substituted Ni3Se4 can hold the optimal d‐p orbital hybridization resulted from the formed more unoccupied antibonding states π*. It inevitably enhances the interfacial charge transfer and ensures the balanced OH− adsorption‐desorption to accelerate the redox kinetics validated by the lowest reaction barrier (0.59 eV, matching well with the theoretical calculations). Coupling with the lower OH− diffusion energy barrier, the prepared cathode delivers ultrahigh rate capability (~68.7 % capacity retention even the current density increases by 200 times), and an assembled HSC also presents high energy/power density. This work establishes the principles for determining heteroatoms and deciphers the underlying effects of the heteroatom substitution on improving redox kinetics and the rate performance of battery‐type electrodes from a novel perspective of orbital‐scale manipulation. [ABSTRACT FROM AUTHOR]

Electrochemical nitrogen reduction reaction (NRR) is considered as an important strategy for ammonia using green energy. Single atom catalysts (SACs) with a metal atom as active site have been shown its advantages to high ammonia yield and low energy consumption. In this work, we proposed a new concept of SACs with the capacity of d‐p orbital hybridization. These computationally designed SACs contained a metal and non‐metal pair anchored on g‐C3N4 slab. Among these SACs studied in the present work, RuB@g‐C3N4 catalyst performed the best activity for NRR with low onset potential of −0.33 V by a two‐step scanning computations using density functional theory (DFT). Moreover, suppressing effectively to the competitive hydrogen evolution reaction (HER) also make it more selective. It was further revealed that the hybridization of d‐p orbitals between metal and nonmetal could regulate the electronics of active sites and facilitate the adsorption and charge transfer of adsorbed N2 molecules resulting in enhanced catalytic performance. This work demonstrated an alternative way to further enhance the catalytic activity of SACs by introducing a non‐metal atom. [ABSTRACT FROM AUTHOR]

Compared with traditional techniques, solid‐state magnetocaloric phase transition materials (MPTMs), based on the giant magnetocaloric effect (GMCE), can achieve a higher energy conversion efficiency for caloric applications. As one of the most promising MPTMs, the hexagonal (Mn,Fe)2(P,Si)‐based compounds host some advantages, but the existing hysteresis and relatively unstable GMCE properties need to be properly tackled. In this study, it is found that substitutions with Ni, Pd, and Pt can maintain and even enhance the GMCE (≈8.7% maximum improvement of |Δsm|). For a magnetic field change of Δμ0H = 2 T, all samples obtain a |Δsm| in the range of 20–25 J kg−1 K−1 with a low thermal hysteresis ΔThys (≤5.6 K). The performance surpasses almost all other (Mn,Fe)2(P,Si)‐based materials with ΔThys (<10 K) reported until now. The occupancy of substitutional Ni/Pd/Pt atoms is determined by X‐ray diffraction, neutron diffraction, and density functional theory calculations. The difference in GMCE properties upon doping is understood from the competition between a weakening of the magnetic exchange interactions and the different degrees of orbital hybridization among 3d‐4d‐5d elements. The studies elaborate on the responsible mechanism and provide a general strategy through d‐block doping to further optimize the GMCE of this materials family. [ABSTRACT FROM AUTHOR]

The incorporation of large‐sized rare earth (RE) elements with high coordination characteristics into transition metal dichalcogenide (TMD) absorbers while preserving a high 1T phase content during post‐processing poses a significant challenge. To address this, a novel strategy involving the confinement of RE elements within the 1T‐MoS2 lattice via liquid plasma assistance, is proposed. This approach effectively mitigates the environmental impact on the 1T phase of MoS2, yielding a remarkable 1T phase content of 82.69% for Ce20‐D7 (20 wt.% Cerium trinitrate and 7 kV applied voltage). Combining experimental and theoretical investigations reveals that the multi‐orbital characteristics of RE elements facilitate hybridization between the RE‐4f and Mo‐4d orbitals on the MoS2 surface, leading to the occupation of weakly bound electrons in bonding orbitals with short‐distance motion, enhanced inter‐orbital electron‐electron interactions, and induced polarization loss. Notably, the results demonstrate that the Pr15‐D7 sample (15 wt.% praseodymium nitrate and 7 kV applied voltage) exhibits an effective absorption bandwidth (EAB) of 7.12 GHz at 2.6 mm, with a minimum reflection loss of ‐52.02 dB while the Ce20‐D7 sample achieves an EAB of 6.96 GHz at 2.7 mm. These findings provide valuable insights for the rational design and development of high‐performance TMD absorbers leveraging RE‐modified materials. [ABSTRACT FROM AUTHOR]

One of the key challenges in separation science is the lack of precise ion separation methods and mechanistic understanding crucial for efficiently recovering critical materials from complex aqueous matrices. Herein, first‐principles electronic structure calculations and in situ Raman spectroscopy are studied to elucidate the factors governing ion discrimination in an adsorptive membrane specifically designed for transition metal ion separation. Density functional theory calculations and in situ Raman data jointly reveal the thermodynamically favorable binding preferences and detailed adsorption mechanisms for competing ions. How membrane binding preferences correlate with the electronic properties of ligands is explored, such as orbital hybridization and electron localization. The findings underscore the importance of the phenolate group in oxime ligands for achieving high selectivity among competing transition metal ions. In‐depth understanding on which specific atomistic site within the microenvironment of metal‐ligand binding pockets governs the ion discrimination behaviors of the host will build a solid foundation to guide the rational design of next‐generation materials for precision separation essential for energy technologies and environment remediation. In tandem, synthetic controllability is demonstrated to transform 3D micrometer‐scale crystals to a 2D crystalline selective layer in membranes, paving the way for more precise and sustainable advances in separation science. [ABSTRACT FROM AUTHOR]

The effects of vacuum and oxygen annealing on Sr2-xNbxIrO4 samples have been systematically investigated. The annealing under vacuum leads to an enhanced insulating state of the Sr2-xNbxIrO4 compounds, which could be due to the evaporation of oxygen atoms which breaks the superexchange interaction between Ir and O ions. The annealing under oxygen atmosphere results in substantial straightening of the in-plane Ir–O–Ir bond and rapid depression of the canted antiferromagnetic ordering state. Importantly, the insulator-to-metal transition has been achieved by oxygen annealing of the Sr2-xNbxIrO4 samples, which could be due to the enhanced hybridization of Ir 5d orbitals with the neighboring O 2p orbitals. The present results suggest that the annealing treatment could be an effective way for exploring of novel physical phenomena in Sr2IrO4 and related compounds. [ABSTRACT FROM AUTHOR]

Orbital hybridization is a promising approach to modulating the electronic structure of the designed electrocatalysts to boost reaction kinetics. In contrast to d‐d hybridization, p‐d orbital hybridization between p‐block elements and d‐block metals can provide new opportunities to modulate the electronic properties and thus promote the catalytic performance. Herein, a phosphorus‐doped osmium (P‐Os) catalyst is designed through ultrafast (20 s) microwave plasma engineering. Theoretical calculations verify the d‐p orbital hybridization between P and Os, leading to the modulation of the d‐band center of the Os active site. Specifically, P neighboring Os exhibit the highest catalytic activity, facilitating crucial processes such as H2O/H* adsorption and dissociation. The overpotential of P‐Os in alkaline seawater is only 152 mV at 1 A cm−2, which is superior to the reported seawater electrocatalysts. Moreover, the synthesized P‐Os catalysts are integrated into an anion exchange membrane (AEM) electrolyzer, demonstrating remarkable performance. The AEM electrolyzer requires 1.86/2.02 V to achieve 500/1000 mA cm−2 current densities. Then, the achieved P‐Os have great potential for practical electrocatalytic water‐splitting applications. [ABSTRACT FROM AUTHOR]

In 6000-series Al-Mg-Si alloys, Zn is commonly added to enhance the aging response for improved properties. However, the segregation of Zn to interfaces and its interaction mechanisms with strengthening phases remain unclear. Combining experiments and theoretical calculations, we systematically investigated Zn segregation behavior at the β″/Al interfaces in Al-Mg-Si alloys. Using a modified β″-Mg5Al2Si4 model, we determined that the interface (100)β″//(130)Al has a slightly smaller formation energy of 1.06 kJ/mol, while (001)β″//( 3 ¯ 20)Al has a relatively smaller interfacial energy of 116 mJ/m2. HAADF-STEM analysis revealed these interfacial morphologies and atomic distributions, showing that Zn atoms not only enter the β″ phase but are also inclined to segregate at the interfaces by occupying the Si3/Al sites. Furthermore, the stability of the β″/Al interfaces and the Zn segregation behavior are well explained at the atomic scale, with calculations showing that stronger hybridization between Zn-3d and Si-3s orbitals facilitates Zn segregation at the interfaces. [ABSTRACT FROM AUTHOR]

Transparent photovoltaics (TPVs) are crucial for developing next‐generation see‐through electronics. However, TPV devices (TPVDs) require wide‐bandgap materials that are typically only responsive to short wavelength (ultraviolet, UV) lights rather than visible lights. Is it possible to improve the TPV performance by harvesting the longer wavelength lights without degradation of transparency? It may be satisfied with the function of intermediate energy states, which can utilize the lower photon energy (longer wavelength light) by a two‐step transition. To achieve this, co‐sputtered Ti‐doped ZnO (Ti:ZnO) film‐based high‐performance TPVDs have been developed. Density functional theory analysis revealed the formation of intermediate energy states due to the hybridization of O 2p and Ti 3d orbitals in the Ti:ZnO system. The Ti:ZnO‐based TPVDs show 65% average visible transparency with a power production value of 655 μW cm−2. These devices exhibit good photodetection behavior under UV to visible illuminations with high responsivity and detectivity values of 1.85 A W−1 and 2.5 × 1013 Jones, respectively. Finally, a high‐performance UV to visible broadband and wide‐field‐of‐view photocommunication system is designed based on the TPVDs to generate the fast Morse code signal. Therefore, Ti doping in ZnO provides a good way to improve the device's functionality for futuristic applications. [ABSTRACT FROM AUTHOR]

The effects of vacuum and oxygen annealing on Sr2-xNbxIrO4 samples have been systematically investigated. The annealing under vacuum leads to an enhanced insulating state of the Sr2-xNbxIrO4 compounds, which could be due to the evaporation of oxygen atoms which breaks the superexchange interaction between Ir and O ions. The annealing under oxygen atmosphere results in substantial straightening of the in-plane Ir–O–Ir bond and rapid depression of the canted antiferromagnetic ordering state. Importantly, the insulator-to-metal transition has been achieved by oxygen annealing of the Sr2-xNbxIrO4 samples, which could be due to the enhanced hybridization of Ir 5d orbitals with the neighboring O 2p orbitals. The present results suggest that the annealing treatment could be an effective way for exploring of novel physical phenomena in Sr2IrO4 and related compounds. [ABSTRACT FROM AUTHOR]

Lithium‐sulfur (Li−S) batteries have many advantages but still face problems such as retarded polysulfides redox kinetics and Li dendrite growth. Most reported single atom catalysts (SACs) for Li−S batteries are based on d‐band transition metals whose d orbital constitutes active valence band, which is inclined to occur catalyst passivation. SACs based on 4f inner valence orbital of rare earth metals are challenging for their great difficulty to be activated. In this work, we design and synthesize the first rare earth metal Sm SACs which has electron‐rich 4f inner orbital to promote catalytic conversion of polysulfides and uniform deposition of Li. Sm SACs enhance the catalysis by the activated 4f orbital through an f‐d‐p orbital hybridization. Using Sm‐N3C3 modified separators, the half cells deliver a high capacity over 600 mAh g−1 and a retention rate of 84.3 % after 2000 cycles. The fabricated Sm‐N3C3‐Li|Sm‐N3C3@PP|S/CNTs full batteries can provide an ultra‐stable cycling performance of a retention rate of 80.6 % at 0.2 C after 100 cycles, one of the best full Li−S batteries. This work provides a new perspective for the development of rare earth metal single atom catalysis in electrochemical reactions of Li−S batteries and other electrochemical systems for next‐generation energy storage. [ABSTRACT FROM AUTHOR]

Developing effective descriptors for perovskite oxygen evolution reaction (OER) electrocatalysts is crucial for advancing clean energy technologies, which are often constrained by incomplete theoretical calculations. Herein, using step‐wise strained (−3–3%) NdNiO3 as a model, the density functional theory (DFT) is employed, considering both bulk superlattice model (B‐model) and surface slab models (S‐model) to garner a set of electronic descriptors. The S‐model‐derived metal─oxygen orbital hybridization is found to agree with the X‐ray absorption spectroscopy (XAS) results, which, however, are disentangled from the observed OER activity trend. Further detailed analysis discovers that the alignment of the calculated O 2p band position with the OER redox potential on an absolute scale can serve as a hitherto unexplored descriptor for comprehending the activity of lattice oxygen and its bonding strength to OH*. Combined DFT and XAS data reveals that excessive strain hinders surface oxygen exchange, slows down the rate‐determining step of OH* adsorption, and impairs the durability of the electrocatalyst by altering the random electron occupancy in frontier orbitals. The work sheds light on the rational design of cost‐effective, high‐performance perovskite‐based electrocatalysts. [ABSTRACT FROM AUTHOR]

Ternary nitrides are rapidly emerging as promising compounds for optoelectronic and energy conversion applications, yet comparatively little of this vast composition space has been explored. Furthermore, the crystal structures of these compounds can exhibit a significant amount of disorder, the consequences of which are not yet well understood. Here, the deposition of bixbyite‐type ZrTaN3 thin films is demonstrated by reactive magnetron co‐sputtering and observed semiconducting character, with a strong optical absorption onset at 1.8 eV and significant photoactivity, with prospective application as functional photoanodes. It is found that Wyckoff‐site occupancy of cations is a critical factor in determining these beneficial optoelectronic properties. First‐principles calculations show that cation disorder leads to minor deviations in the total energy but modulates the bandgap by 0.5 eV, changing orbital hybridization of valence and conduction band states. In addition to demonstrating that ZrTaN3 is a promising visible light‐absorbing semiconductor and active photoanode material, the findings provide important insights regarding the role of cation ordering on the electronic structure of ternary semiconductors. In particular, it is shown that not only cation order, but also the cationic Wyckoff site occupancy has a substantial impact on key optoelectronic properties, which can guide future design and synthesis of advanced semiconductors. [ABSTRACT FROM AUTHOR]

The exquisite precision of atom interferometers has sparked the interest of a large community for uses ranging from fundamental physics to geodesy and inertial navigation. However, their implementation for onboard applications is still limited, not least because rotation and acceleration are intertwined in a single phase shift, which makes the extraction of a useful signal more challenging. Moreover, the spatial separation of the wave packets due to rotations leads to a loss of signal. We present an atom interferometer operating over a large range of random angles, rotation rates and accelerations. A model of the expected phase shift allows us to untangle the rotation and acceleration signals. We also implement a real-time compensation system using fiber-optic gyroscopes and a rotating reference mirror to maintain the full contrast of the interferometer. We demonstrate a single-shot sensitivity to acceleration of 24 μg for rotation rates reaching 14° s−1. Cold atoms inertial sensors offer great precision and sensitivity, yet their use in mobile applications has been hindered by the effects of rotations on their measurements. Here, authors demonstrate an atom interferometer operating over a wide range of orientations and rotation rates, thanks to hybridisation with accelerometers and gyroscopes. [ABSTRACT FROM AUTHOR]

The hydrogen evolution reaction (HER) in alkaline electrolytes using transition metal dichalcogenides is a research area that is not tapped into. Alkaline HER ( 2H2O+2e-→H2+OH- ${{2H}_{2}O+2{e\ }^{-}\to {H}_{2}+{OH}^{-}{\rm \ }}$ ) is harder to achieve relative to acidic HER ( H++2e-→H2 ${{H}^{+}+2{e\ }^{-}\to \ {H}_{2}}$ ), this is attributed to the additional water dissociation step that occurs in basic HER to generate H+ ions. In fact, for most catalysts, their HER activity decreases tremendously when the electrolyte is changed from acidic to basic conditions. Platinum dichalcogenides, PtX2 (X=S, Se, Te), are an interesting member of transition metal dichalcogenides (TMDs) as these show an immense hybridization of the Pt d orbitals and chalcogen p orbitals because of closely correlated orbital energies. The trend in electronic properties of these materials changes drastically as the chalcogen is changed, with PtS2 reported to exhibit semi‐conductor properties, PtSe2 is semi‐metallic or semi‐conductive, depending on the number of layers, while PtTe2 is metallic. The effect of varying the chalcogen atom on the HER activity of Pt dichalcogenides will be studied. Pt dichalcogenides have previously been prepared by direct high‐temperature chalcogen deposition of Pt substrate and evaluated as electrocatalysts for HER in H2SO4. The previously employed synthesis procedures for PtX2 limit these compounds′ mass production and post‐synthesis treatment. In this study, we demonstrated, for the first time the preparation of PtSe2 and PtTe2 by colloidal synthesis. Colloidal synthesis offers the possibility of large‐scale synthesis of materials and affords the employment of the colloids at various concentrations in ink formulation. The electrochemical HER results acquired in 1 M KOH indicate that PtTe2 has a superior HER catalytic activity to PtSe2. A potential of 108 mV for PtTe2 and 161 mV for PtSe2 is required to produce a current density of −10 mA cm−2 from these catalysts. PtTe2 has a low Tafel slope of 79 mVdec−1, indicating faster HER kinetics on PtTe2. Nonetheless, the stability of these catalysts in an alkaline medium needs to be improved to render them excellent HER electrocatalysts. [ABSTRACT FROM AUTHOR]

The utilization of green hydrogen sources in H2O for alkynols electrocatalytic semihydrogenation reaction (ESHR) at ambient temperature provides a promising pathway toward the sustainable conversion of alkynols. However, it is still a great challenge to construct specific interfacial structure to adjust the electronic structure of Pd for the purpose of altering the strong adsorption of Pd with active hydrogen to enhance the production of alkenols. Here, the atomically dispersed GaOx‐PdMo bimetallene nanoribbons (GaOx‐PdMo BNRs) via oxygen bridging Ga atoms is designed to the surface of PdMo BNRs for 2‐methyl‐3‐butyn‐2‐ol (MBY) ESHR to the synthesis of 2‐methyl‐3‐buten‐2‐ol (MBE). The GaOx‐PdMo BNRs achieve the excellent MBE selectivity (≈97.4%), Faraday efficiency (≈96.1%), and maintain long‐term stability. Density functional theory demonstrates that the top electron‐enriched Ga atoms and the bottom electron‐deficient Pd atoms construct a “pyramidal” interface via the oxygen bridge. The unique surface can effectively activate H2O and weaken interaction between catalyst and MBE, thus promoting MBE generation. Moreover, the electron bridge effect between Ga‐O‐PdMo can induce p‐d orbital hybridization to achieve lower the d‐band center of surface Pd thus modulating the reactants adsorption. This work provides a strategy to improve ESHR performance by electron bridge effect to modulate interfacial electron distribution. [ABSTRACT FROM AUTHOR]

Orbital degree of freedom plays a crucial role in governing the physical and chemical properties of solid materials, and it is widely investigated in the fields of physics, material science, and chemistry. Typically, orbital‐energy‐related scenarios, such as d‐band center or electron occupancy, have been discussed in the catalytic materials, since they can control the surface‐adsorbate bonding strength to modulate the catalytic activity. However, the impact of orbital morphology, that is the "posture" of orbitals on catalysts' surfaces, has never been studied. Here the importance of 3d‐orbital morphology on the activity of oxygen reduction reaction (ORR) in a strongly correlated oxide α‐Ti2O3 is highlighted. Superior ORR performance is observed in α‐Ti2O3 (Ti3+:3d1) than that of the anatase and rutile TiO2 (Ti4+:3d0), with higher Faradaic efficiency (87.3%) and H2O2 selectivity (93.2%). More importantly, a novel orbital‐morphology‐based mechanism is developed and the orbital morphology dominates the catalytic activity by determining the surface‐adsorbates d–p orbital hybridization via orbitals' overlap, resulting in a crystal‐plane‐dependent ORR activity in α‐Ti2O3. The work reveals the strong interplay between the orbital morphology, d–p hybridization, and ORR activity, which broadens the fundamental understanding of catalysts from a new view of the orbital degree of freedom. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The organic cocrystal strategy has provided a convenient and efficient platform for preparing organic photothermal materials. However, the rapidly directional preparation of cocrystals with desirable photothermal properties remains challenging due to a lack of suitable design ideas. Here, two new photothermal cocrystals, MTC and MFC, based on acceptor molecules (TCNQ and F4TCNQ) with different electron‐withdrawing capacities were quickly prepared by the coprecipitation method, aiming to explore the effect of charge transfer (CT) interaction on photothermal properties. Compared with MTC, the stronger intermolecular CT interaction in MFC facilitates extending the absorption range (from the NIR‐I to the NIR‐II region) and enhancing the non‐radiative transition process. Under the 808 nm laser irradiation, the photothermal conversion efficiency (PCE) of MFC is 54.6%, whereas MTC displays a mere 36.8%. The MFC cocrystal was further combined with a flexible polymer substrate (HPDMS) to prepare a flexible wearable heater (HPDMS@MFC), which exhibits excellent NIR‐II photothermal performance. This work points out a research direction for the rapid assembly of efficient photothermal cocrystals and additionally provides an extensive application prospect for organic photothermal cocrystals in the field of wearable devices. [ABSTRACT FROM AUTHOR]

[Display omitted] K-doped Mn–Ce solid solution catalysts were synthesized using a combination of coprecipitation and hydrothermal methods, demonstrating excellent performance in benzene oxidation. The catalyst K 1 Ce 5 Mn 5 exhibited comparable activity to noble metal catalysts, achieving a 90 % benzene conversion at approximately 194 ℃. Durable tests under dry and moist conditions revealed that the catalyst could maintain its activity for 50 h at 218 ℃ and 236 ℃, respectively. Characterization results indicated that the catalyst's enhanced activity resulted from the weakened Mn–O bonding caused by the introduction of K+, facilitating the activation of oxygen and its involvement in the reaction. CeO x , the main crystalline phase of Mn–Ce solid solutions, provided abundant oxygen vacancies for capturing and activating oxygen molecules for the weakened Mn–O structures. This conclusion was further supported by partial density of state analysis from density functional theory computations, revealing that the introduction of K+ weakened the orbital hybridization of Mn3d and O2p. Finally, in situ diffuse reflectance infrared Fourier-transform spectroscopy (in situ DRIFTS) studies on Ce 5 Mn 5 and K 1 Ce 5 Mn 5 catalysts suggested that the introduction of K+ promoted the conversion of adsorbed benzene. Furthermore, intermediate products were transformed more rapidly for K 1 Ce 5 Mn 5 compared to Ce 5 Mn 5. [ABSTRACT FROM AUTHOR]

Comprehensive Summary We present a strategy that effectively modulate the d‐band electronic structure of the active center by strain effect and interatomic orbital hybridization. This strategy efficiently promotes the kinetic process of the ethanol oxidation reaction (EOR) in alkaline media. In the intermetallic Pd3Pb nanowires, the introduction of Pb not only causes the lattice expansion of Pd but also achieves the interatomic orbital hybridization bonding with Pd. Such interatomic orbital hybridization effect and tensile strain effect can effectively achieve a co‐regulation of the d‐band electronic structure of Pd, which directly affects the adsorption behavior of intermediate on Pd for EOR. Hence, the intermetallic Pd3Pb nanowires demonstrate enhanced EOR activity and anti‐poisoning ability against COads. Theoretical calculations show that the enhanced OH* adsorption ability and the low energy barrier for the oxidative dehydrogenation of ethanol are the keys to high EOR activity and stability of the intermetallic Pd3Pb nanowires. [ABSTRACT FROM AUTHOR]

In the quest to elevate the sodium‐ion intercalation kinetics of transition metal oxide electrodes, the intrinsic low conductivity of these materials often acts as a bottleneck, restricting Na+ storage. Herein, the mechanism behind sodium‐ion diffusion kinetics in MnO2 is explored, specifically focusing on the manipulation of π* antibonding orbital occupancy. This is accomplished through strategic doping with strongly electron‐withdrawing Rh3+ (t2g6eg0), enhancing the hybridization of Mn 3d‐O 2p orbitals and significantly increasing the electrical conductivity of MnO2. Density functional theory (DFT) calculations and X‐ray absorption spectroscopy (XAS) results demonstrate that the smaller orbital energy difference between Rh3+eg and Mn4+t2g, compared to that between Rh3+eg and Mn4+eg, fosters direct electron transfer from the Mn4+t2g to the vacant Rh3+eg. This electron movement induces an upshift in the Mn‐t2g orbital energy levels while concurrently diminishing the occupancy of π* antibonding orbitals formed via Mn t2g‐O 2p hybridization. The resultant Rh‐MnO2 electrode exhibits an impressive specific capacity of 335 F g−1 at 1 A g−1 and a substantial rate capacity of 224.8 F g−1 at 20 A g−1. This investigation elucidates the intricate mechanism underlying the sluggish kinetics of sodium ion intercalation within transition metal oxide frameworks. [ABSTRACT FROM AUTHOR]

The intricate nature of magnetism in uranium-based Kondo lattices is a consequence of correlations between U-5f and conduction electrons. Previously, the source of magnetism has been ascribed to either Mott physics or Ruderman-Kittel-Kasuya-Yosida interaction, both of which are not fully applicable to uranium-based Kondo lattices. Using linearized quasiparticle self-consistent GW plus dynamical mean-field theory, we demonstrate a crossover from incoherent to coherent f-d Kondo cloud in the paramagnetic phase of UTe2, USbTe and USbSe. As the transition occurs, we observe an augmented f-d coherence and Pauli-like magnetic susceptibility, with a substantial frozen magnetic moment of U-5f persisting. We show that momentum dependent f-d hybridization is responsible for the magnetic moments arising from the renormalized f electrons' van Hove singularity. Our findings provide a perspective to explain the dual nature of magnetism and the long-range magnetic ordering induced by pressure in UTe2. This work aims at clarifying the puzzling magnetism of several U intermetallics, in particular the pressure-induced magnetism of UTe2. By an ab initio treatment of electronic correlations, the authors show that a momentum dependent f-d hybridization is responsible for the magnetic moments arising from the van Hove singularity of renormalized f electrons. [ABSTRACT FROM AUTHOR]

The contents of alkali and alkaline earth metals are higher in Zhundong coal, and there are serious problems of slagging and fouling during the combustion process. Therefore, it is of great significance to reveal the mechanism of slagging and fouling in the boiler of Zhundong coal. In this paper, first-principle calculations based on density functional theory are used to study the competition mechanism of alkaline metal oxides during the combustion process in Zhundong coal by establishing the Na2O(110)/CaO(100)-SiO2(100) double-layer interface model. The results show that the bond lengths of the surface of Na2O(110) and CaO(100) with SiO2(100) after adsorption were generally lengthened and the value of bond population became smaller, which formed a stable binding energy during the reaction. The electron loss of Na is 0.05 e, the electron loss of Ca is 0.03 e, and the electron loss of Na2O is greater than that of CaO. The charge transfer on the surface of Na2O with SiO2 is obviously higher than that of CaO and the orbital hybridization on the surface of CaO with SiO2 is weaker than that on the surfaces of Na2O with SiO2. Na2O is easier to react with SiO2 than CaO. The adsorption energies on the surface of Na2O and CaO with SiO2 are −5.56 eV and −0.72 eV, respectively. The adsorption energy of Na2O is higher than that of CaO, indicating that Na2O is more prone to adsorption reactions and formation of Na-containing minerals and other minerals, resulting in more serious slagging. In addition, the XRD analyses at different temperatures showed that Na-containing compounds appeared before Ca-containing ones, and the reaction activity of Na2O is stronger than that of CaO in the reaction process. The experimental results have good agreement with the calculation results. This provides strong evidence to reveal the slagging and fouling of Zhundong coal. [ABSTRACT FROM AUTHOR]

Although outstanding detectivities, InGaAs photodetectors for optic fiber communication are often costly due to the need for cooling. Therefore, cryogen-free and cost-effective alternatives working in telecommunication bands are highly desired. Here, we present a design of hot-electron photodetectors (HE PDs) with attributes of room-temperature operation and strong optical absorption over S and C bands (from 1460 to 1565 nm). The designed HE PD consists of a metal–semiconductor–metal hot-electron stack integrated with a front grating. Optical simulations reveal that mode hybridizations between Fabry–Pérot resonance and grating-induced surface plasmon excitation lead to high absorption efficiencies (≥0.9) covering S and C bands. Probability-based electrical calculations clarify that device responsivity is mainly determined by working wavelength on the premise of broadband strong absorption. Moreover, through comparison studies between the grating-assisted HE PD and purely planar microcavity system that serves as a reference, we highlight the design superiorities in average absorption and average responsivity with optimized values of 0.97 and 0.73 mA W−1, respectively. The upgraded peformances of the designed device are promising for efficient photoelectric conversion in optic fiber communication systems. [ABSTRACT FROM AUTHOR]

The adsorption of N2O on flat and defective Cu (110) surfaces has been studied using pure density functional theory (DFT) and DFT with Hubbard U, including van der Waals (vdW) corrections of the form vdW-DF. The calculations show that for GGA-PBE, as the exchange-correlation and vdW-DF functionals are considered, N2O molecule interacts very weakly with the flat Cu (110) surface, while the presence of the Cu-adatom results in better stability of adsorbed N2O compared to one on the perfect surface. Also, the inclusion of U parameter to PBE and vdW-DF functionals reduces the values of the adsorption energy relative to the standard PBE and vdW-DF functionals with or without spin-polarization. Finally, the analysis of the projected density of states shows a strong hybridization between the Cu-3d band and N-2p orbital. Our investigation suggests that the Cu (110) surface can serve as a catalytic medium that is able to adsorb the harmful N2O molecule. [ABSTRACT FROM AUTHOR]

Fluorescent tiny molecules that are resistant to acid have long been the center of interest. The nitrogen atoms on benzyl cyanide were sp hybridized, while the two nitrogen atoms at pyrimidine were sp2 hybridized in the primary structure that we constructed. With the addition of a protonic acid (H2SO4, CH3SO3H, and HF), the nitrogen atoms at acridine underwent sp3 hybridization, which caused the hydrogen protons to interact with the three types of nitrogen atoms to varying degrees. This distribution of the electron cloud density led to a decrease in fluorescence emission. Furthermore, Gaussian 09 software and DFT calculations were used to model its orbital conformation, which is the highest occupied molecular orbital—lowest unoccupied molecular orbital (HOMO–LUMO). Furthermore, its crystal structure was assigned to the orthorhombic system with stronger non-homogeneity (a = 8.9160 (4) Å, b = 44.289 (3) Å, c = 9.6131 (7) Å, α = 90°, β = 90°, γ = 90°, V = 3796.0 (4) Å3, z = 4, Dc = 1.244 g/cm3). [ABSTRACT FROM AUTHOR]

Removal of high toxic Cr(VI) with solar plays an important role in improving water pollution, but is facing a dilemma of developing excellent photocatalysts with high conversion efficiency and low cost. Different from traditional nano-structuring, this work focuses on the interfacial hybridization by considering the intrinsic difference in bonding interaction. Herein, we intentionally make some layered black phosphorus (BP) sheets with Van der Waals interaction to bond with ZnO surfaces, in which some additional electron channels can be formed by this multilevel atomic hybridization to accelerate carrier transfer and separation. Compared to the pristine ZnO and BP nanosheets, the light absorption and carrier separation efficiency can be sharply enhanced by this particular electronic structure, which makes the Cr reduction performance enhanced about 7.1 times. Our findings suggest a new insight into accelerating Cr(VI) reduction by designing interfacial atom hybridization. [ABSTRACT FROM AUTHOR]

The optoelectronic properties of non-metal (B, N, O, C, F) doped and biaxial tensile strain in the x–y direction of O-doped and N-doped ZrSe2, including energy band structure, density of states, dielectric function, and absorption coefficients, have been calculated by a first-principles approach based on density-functional theory. It is shown that the doped system has a low formation energy, indicating that the structure can exist stably. The B, C, and N atom-doped systems show impurity energy levels near the Fermi energy level, narrowing the bandgap, enhancing the electron transport ability, and increasing the electrical conductivity. Biaxial stretching was applied to the ZrSe2 structure before and after O and N doping, and it was found that the stability of the ZrSe2, Zr9Se 1 7 O 1 , and Zr9Se 1 7 N1 structures was found to decrease gradually with increasing strain. The energy bandwidth of the doped system in the Zr9Se 1 7 O1system at a tensile strain of 4% is a maximum of 0.924 eV; from the density of states, it is found that there is a very obvious orbital hybridization of Se-4p and Zr-d. The doped system has the largest effect on the dielectric function at 6% tensile strain and on the absorption coefficient at 8%. In the Zr9Se 1 7 N1 system, stretching 8% energy bandwidth is a maximum of 0.788 eV, the tensile strain of 8% has the greatest effect on the dielectric function, and a tensile strain of 6% has the most significant effect on the absorption coefficient. [ABSTRACT FROM AUTHOR]

The optoelectronic properties of non-metal (B, N, O, C, F) doped and biaxial tensile strain in the x–y direction of O-doped and N-doped ZrSe2, including energy band structure, density of states, dielectric function, and absorption coefficients, have been calculated by a first-principles approach based on density-functional theory. It is shown that the doped system has a low formation energy, indicating that the structure can exist stably. The B, C, and N atom-doped systems show impurity energy levels near the Fermi energy level, narrowing the bandgap, enhancing the electron transport ability, and increasing the electrical conductivity. Biaxial stretching was applied to the ZrSe2 structure before and after O and N doping, and it was found that the stability of the ZrSe2, Zr9Se 1 7 O 1 , and Zr9Se 1 7 N1 structures was found to decrease gradually with increasing strain. The energy bandwidth of the doped system in the Zr9Se 1 7 O1system at a tensile strain of 4% is a maximum of 0.924 eV; from the density of states, it is found that there is a very obvious orbital hybridization of Se-4p and Zr-d. The doped system has the largest effect on the dielectric function at 6% tensile strain and on the absorption coefficient at 8%. In the Zr9Se 1 7 N1 system, stretching 8% energy bandwidth is a maximum of 0.788 eV, the tensile strain of 8% has the greatest effect on the dielectric function, and a tensile strain of 6% has the most significant effect on the absorption coefficient. [ABSTRACT FROM AUTHOR]

As a green alternative to cement-based materials, alkali-activated silicate materials (AASM) have garnered attention for their ability to reduce greenhouse gas emissions and efficiently utilize industrial waste. During AASM preparation, Si monomers such as [SiO 2 (OH) 2 ]2-, [SiO(OH) 3 ]-, Si(OH) 4 play a crucial role in governing the formation rate and unique gel structure of AASM. Despite their widespread use in construction, the microscopic mechanism of Si monomer formation from reactive SiO 2 groups via reconstruction reactions (RR) remains unclear. This study comprehensively explored the structural transformations, formation pathways, and electron transfer mechanisms of Si monomers in AASM gels during RR using molecular dynamics (MD) simulations and first-principles calculations. We identified six distinct formation pathways for three Si monomers, with SiO 2 → SiO 2 H 2 O → SiO 2 (H 2 O) 2 → SiO(OH) 2 H 2 O exhibiting the highest energy barrier of 16.61kJ/mol. Further analysis revealed a correlation between energy barriers and orbital hybridization strength, providing new insights into Si monomer formation mechanisms in AASM. This lays a solid foundation for optimizing AASM's preparation and enhancing its performance, further promoting the environmental friendliness and efficient utilization of AASM. • The study pioneered a reconstruction reaction gel model and verified its precision. • For the first time, a hybrid approach combining molecular dynamics and first-principles calculations was used to study alkali-activated silicate materials. • Molecular dynamics simulations accurately replicated the formation of three silicon monomers and their reaction pathways. • The study revealed variations in reaction energy barriers from an electron transfer perspective. [ABSTRACT FROM AUTHOR]

The recently introduced topological heavy fermion model (THFM) provides a means for interpreting the low-energy electronic degrees of freedom of the magic angle twisted bilayer graphene as hybridization amidst highly dispersing topological conduction and weakly dispersing localized heavy fermions. In order to understand the Landau quantization of the ensuing electronic spectrum, a generalization of THFM to include the magnetic field B is desired, but currently missing. Here we provide a systematic derivation of the THFM in B and solve the resulting model to obtain the interacting Hofstadter spectra for single particle charged excitations. While naive minimal substitution within THFM fails to correctly account for the total number of magnetic subbands within the narrow band i.e., its total Chern number, our method—based on projecting the light and heavy fermions onto the irreducible representations of the magnetic translation group— reproduces the correct total Chern number. Analytical results presented here offer an intuitive understanding of the nature of the (strongly interacting) Hofstadter bands. The recently-developed topological heavy fermion model explains the low energy electrons of magic-angle twisted bilayer graphene as a hybridization between states localized at AA stacking sites and itinerant topological states, denoted by f and c electrons in analogy to heavy fermion systems. Here, the authors extend this model to a nonzero magnetic field, obtaining interacting Hofstadter spectra in the flatband limit by analytic methods. [ABSTRACT FROM AUTHOR]

The efficient segregation of radioactive nuclides from low-level radioactive liquid waste (LLRW) is paramount for nuclear emergency protocols and waste minimization. Here, we synthesized Na3FePO4CO3 (NFPC) via a one-pot hydrothermal method and applied it for the first time to the selective separation of Sr2+ from simulated LLRW. Static adsorption experimental results indicated that the distribution coefficient Kd remained above 5000 mL·g−1, even when the concentration of interfering ions was more than 40 times that of Sr2+. Furthermore, the removal efficiency of Sr2+ showed no significant change within the pH range of 4 to 9. The adsorption of Sr2+ fitted the pseudo-second-order kinetic model and the Langmuir isotherm model, with an equilibrium time of 36 min and a maximum adsorption capacity of 99.6 mg·g−1. Notably, the adsorption capacity was observed to increment marginally with an elevation in temperature. Characterization analyses and density functional theory (DFT) calculations elucidated the adsorption mechanism, demonstrating that Sr2+ initially engaged in an ion exchange reaction with Na+. Subsequently, Sr2+ coordinated with four oxygen atoms on the NFPC (100) facet, establishing a robust Sr-O bond via orbital hybridization. [ABSTRACT FROM AUTHOR]

[Display omitted] • The surface modification can significantly raise the limiting potential with −1.24 V (Ti 2 NF 2) to −0.21 V (Ti 2 BSe 2). • hybridization of the σ 2 p and π* 2 p with Ti 3 d orbitals leads to the evident splitting and downshifting of the σ and π* orbitals. • The work function plays a crucial role to predict the NRR performance by the Gibbs free energy change of the rate-determining step, which can be regulated through the surface termination of MXenes. The electrochemical conversion of nitrogen to ammonia provides an encouraging method to substitute the traditional Haber-Bosch process, owing to its high efficiency and mild reaction conditions. The search for high-performance catalysts and comprehension of catalytic mechanisms remains significant challenges. Herein, we conduct a systematic theoretical calculation of the NRR performance and mechanism of 24 Ti 2 XT 2 (X = B, C, N; T = F, Cl, Br, I, O, S, Se, Te) MXenes with a T -vacancy to explore the influence of surface functional terminations and non-metallic center elements. Our findings demonstrate that surface functionalization significantly reduces the limiting potential by altering the rate-determining step. This change ranges from −1.24 V (Ti 2 NF 2) to −0.21 V (Ti 2 BSe 2), signifying the remarkable efficacy of modification of the surrounding environment of the exposed transition metal active center in promoting electrocatalytic performance. Detailed investigation of the charge density difference and orbital interaction reveals that the different NRR performance originates from the surface termination and non-metallic atoms regulate the electronic properties of the active Ti atoms. We also introduce the free energy change of *NNH 2 (Δ G *NNH2) as a descriptor to predict the performance of NRR, which exhibits satisfactory linear relationship with free energy change of different intermediates and displays favourable volcano plot with limiting potential. Moreover, we highlight the pivotal role of work function in tuning the energy barrier of the rate-determining step, which can be regulated through the surface modification of MXenes. Our study not only offers a comprehensive understanding of the crucial impact of surface modification on the catalytic activities of defective MXenes, but also provides a rational perspective for designing efficient NRR catalysts. [ABSTRACT FROM AUTHOR]

The d-p orbital hybridization between the d orbitals of Fe-N 4 moieties and the p orbitals of iodine species (I 2 and ICl) leads to enhanced adsorption for iodine species, suppressed ICl hydrolysis and I 3 – formation, and efficient catalysis of the iodine redox reactions. The proposed 4eZIB demonstrate high areal capacities (> 3 mAh cm−2) and improved cycling stability (10,000 cycles) at both RT and –20 °C. [Display omitted] The successive I–/I0/I+ redox couples in the four-electron zinc-iodine aqueous battery (4eZIB) is plagued by the instability of the electrophilic I+ species, which could either be hydrolyzed or be neutralized by the I 3 – redox intermediates. We present an adsorption-catalysis approach that effectively suppresses the hydrolysis of ICl species and also provides an enhanced reaction kinetics to surpass the formation of triiodide ions. We elucidate that the improved stability is attributed to the pronounced orbital hybridization between the d orbitals of Fe-N 4 moieties (atomic Fe supported on nitrogen doped carbon) and the p orbitals of iodine species (I 2 and ICl). Such d-p orbital hybridization leads to enhanced adsorption for iodine species, increased energy barrier for proton detachment from the ICl·HOH intermediate during hydrolysis, and efficient catalysis of the iodine redox reactions with high conversion efficiency. The proposed 4eZIB demonstrates practical areal capacity (>3 mAh cm−2) with a near-unity coulombic efficiency, high energy density of 420 Wh kg−1 (based on cathode mass), and long-term stability (over 10,000 cycles). Even at –20 °C, the battery exhibits stable performance for over 1000 cycles with high iodine utilization ratio. [ABSTRACT FROM AUTHOR]

Fe–N–C catalysts are emerging as promising alternatives to Pt‐based catalysts for the oxygen reduction reaction (ORR), while they still suffer from sluggish reaction kinetics due to the discontented binding affinity between the Fe‐N4 sites and oxygen‐containing intermediates, and unsatisfactory stability. Herein, a flexible multichannel carbon fiber membrane immobilized with atomically dispersed Fe‐N4 sites and neighboring Fe nanoclusters/nanoparticles (FeN4‐FeNCP@MCF) is synthesized. The optimized geometric and electronic structures of the Fe atomic sites brought by adjacent Fe nanoclusters/nanoparticles and hierarchically porous structure of the carbon matrix endow FeN4‐FeNCP@MCF with outstanding ORR activity and stability, considerably outperforming its counterpart with FeN4 sites only and the commercial Pt/C catalyst. Liquid and solid‐state flexible zinc–air batteries employing FeN4‐FeNCP@MCF both exhibit outstanding durability. Theoretical calculation reveals that the Fe nanoclusters can trigger remarkable electron redistribution of the FeN4 sites and modulate the hybridization of central Fe 3d and O 2p orbitals, facilitating the activation of O2 molecules and optimizing the adsorption capacity of oxygen‐containing intermediates on FeN4 sites, and thus accelerating the ORR kinetic. This work offers an effective approach to constructing coupling catalysts that have single atoms coexisting with nanoclusters/nanoparticles for efficient ORR catalysis. [ABSTRACT FROM AUTHOR]

We report a determinant quantum Monte Carlo study of a two-band model, inspired by infinite-layer nickelates, focusing on the influence of interlayer hybridization between 3 d x 2 − y 2 orbitals derived from Ni (or Ni and O) in one layer and rare-earth (R) 5d orbitals in the other layer, hereafter the Ni and R layers, respectively. For a filling with one electron shared between the two layers on average, interlayer hybridization leads to "self-doped" holes in the Ni layer and the absence of antiferromagnetic ordering, but rather the appearance of spin-density and charge-density stripe-like states. As the interlayer hybridization increases, both the Ni and R layers develop antiferromagnetic correlations, even though either layer individually remains away from half-filling. For hybridization within an intermediate range, roughly comparable to the intralayer nearest-neighbor hopping tNi, the model develops signatures of Kondo-like physics. [ABSTRACT FROM AUTHOR]

The formation and stability of solids and molecules is not possible without chemical bonds, which are divided into covalent, ionic, metallic, and van der Waals bonds. A special type of intermolecular bond is hydrogen bonding, which plays a crucial role for chemical, biological, and physical processes. However, hydrogen shows a far more complex behavior when it is present in solids. In this paper, it is shown that the chemical bonding of hydrogen atoms and molecules extends far beyond the simple picture of conventional, ionic, covalent, and multicenter bonds. The interaction of H with its host material is particularly important for hydrogen storage in metallic materials such as Ti3C2${\rm Ti}_{3}{\rm C}_{2}$ MXenes. Hydrogen atoms and H2${\rm H}_2$ molecules form multicenter bonds in Ti3C2${\rm Ti}_{3}{\rm C}_{2}$. On the surface and between two Ti3C2${\rm Ti}_{3}{\rm C}_{2}$ sheets this is limited to the formation of H–Ti bonds. However, H and H2${\rm H}_2$ on interstitial sites form multicenter bonds not only with nearest neighbor Ti atoms but also with carbon atoms. Interestingly, the H–C bonds are characterized by the formation of s–p hybrid orbitals. For H2${\rm H}_2$ molecules, multicenter bond formation is accompanied by an increase of the bond length to 2.07 and 1.85 Å for H2${\rm H}_2$ on the surface and at the interstitial site, respectively. On the other hand, placing H2${\rm H}_2$ between two sheets of Ti3C2${\rm Ti}_{3}{\rm C}_{2}$ leads to dissociation. For all H and H2${\rm H}_2$ complexes the vibrational eigenmodes are calculated. Their frequencies are in the range of 890 to 1610 cm−1${\rm cm}^{-1}$, which indicates that the bonds are remarkably strong. [ABSTRACT FROM AUTHOR]