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Electrocatalytic NO3− reduction to NH3 (NO3RR) is an efficient strategy to simultaneously mitigate NO3− contamination and produce sustainable NH3. Herein, atomically dispersed Sn confined in FeS2 (Sn‐FeS2) is reported as an effective and robust NO3RR catalyst, achieving a maximum NH3‐Faradaic efficiency of 96.7% with a corresponding NH3 yield rate of 15.8 mg h−1 cm−2, along with an excellent catalytic stability. Atomic coordination characterizations of Sn‐FeS2 unravel that single‐atomic Sn bonds with the surrounding Fe atoms to construct the unique p‐d hybridized Sn‐Fe pair sites. Combining theoretical investigations and operando spectroscopic measurements unveil that Sn‐Fe pair sites can synergistically promote the NO3− activation and N═O bond dissociation, accelerate the protonation energetics of NO3−‐to‐NH3 pathway and suppress the competing hydrogen evolution, eventually drastically enhancing the NO3RR activity and selectivity. [ABSTRACT FROM AUTHOR]

Recently, thorium hydride ThH9 possessing a H‐rich clathrate structure has been experimentally synthesized to exhibit a superconducting transition temperature Tc of 146 K at 170–175 GPa, while the more H‐rich clathrate thorium hydride ThH18 is theoretically predicted to reach a Tc of 296 K at 400 GPa. Using first‐principles calculations, it is found that ThH9 has a more ionic character between Th atoms and H cages than ThH18 and that the latter has a more substantial hybridization of the Th 6p semicore and H 1s states than the former. These different bonding characteristics of ThH9 and ThH18 reflect the very large difference in their stabilization pressures. Furthermore, it is revealed that the H‐derived density of states at the Fermi level EF is about two times larger in ThH18 than in ThH9, which in turn leads to the significant large differences in the electron–phonon coupling (EPC) constant and Tc between the two thorium hydrides. The findings not only present the different bonding and EPC characteristics of ThH9 and ThH18 but also have important implications for the design of H‐rich, high‐Tc clathrate metal hydrides. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O) is an industrial waste gas (e.g., from the production of adipic acid), which damages the ozone layer and causes the greenhouse effect. Density functional theory calculations were employed to investigate the mechanism of direct catalytic decomposition of N2O and selective catalytic reduction (SCR) of N2O by CO over Fe-ZSM-5 zeolites. Two stable Fe-active sites with six-membered ring structures on Fe-ZSM-5 were considered. The calculations indicate that the decomposition of N2O is affected by the coordination environment around Fe and can occur through two reaction pathways. However, there is invariably a more considerable energy hurdle for the initiation of the second stage of N2O decomposition. When CO participated in the reaction, it showed good reactivity and stability, the reaction energy barriers of the rate-limiting step were reduced by roughly 20.57 kcal/mol compared to the direct catalytic decomposition of N2O. CO exhibited a superior electron-donating ability and orbital hybridization performance during the reaction, which enhanced the cyclicity of the N2O reduction catalytic process. Our calculations confirmed the significant role of CO in N2O reduction over Fe-ZSM-5 observed in previous studies. This study provides a valuable theoretical reference for exploring CO-SCR methods for N2O reduction over Fe-based zeolite catalysts. [ABSTRACT FROM AUTHOR]

Highlights: The tailored KCoMnNiMgZnF3-HEC cathode delivers extremely high discharge capacity (22,104 mAh g−1), outstanding long-term cyclability (over 500 h), preceding majority of traditional catalysts reported. Entropy effect of multiple sites in KCoMnNiMgZnF3-HEC engenders appropriate regulation of 3d orbital structure, leading to a moderate hybridization with the p orbital of key intermediate. The homogeneous nucleation of Li2O2 is achieved on multiple cation site, contributing to effective mass transfer at the three-phase interface, and thus, the reversibility of O2/Li2O2 conversion. High-entropy catalysts featuring exceptional properties are, in no doubt, playing an increasingly significant role in aprotic lithium-oxygen batteries. Despite extensive effort devoted to tracing the origin of their unparalleled performance, the relationships between multiple active sites and reaction intermediates are still obscure. Here, enlightened by theoretical screening, we tailor a high-entropy perovskite fluoride (KCoMnNiMgZnF3-HEC) with various active sites to overcome the limitations of conventional catalysts in redox process. The entropy effect modulates the d-band center and d orbital occupancy of active centers, which optimizes the d–p hybridization between catalytic sites and key intermediates, enabling a moderate adsorption of LiO2 and thus reinforcing the reaction kinetics. As a result, the Li–O2 battery with KCoMnNiMgZnF3-HEC catalyst delivers a minimal discharge/charge polarization and long-term cycle stability, preceding majority of traditional catalysts reported. These encouraging results provide inspiring insights into the electron manipulation and d orbital structure optimization for advanced electrocatalyst. [ABSTRACT FROM AUTHOR]

The lithium–oxygen battery has the highest theoretical specific energy among all battery systems, while the actual value falls significantly short. The hindered oxygen and/or electron transport result(s) in limited utilization of the porous air electrode, while achieving a quantitative understanding of the electrochemistry and mass transport coupling is challenging. Herein, a porous electrode with highly consistent and controllable channel units is pioneered that excludes the randomness of disordered pores and consequently enables the investigation of control mechanisms. A three‐dimensional dynamic heterogeneous model is developed, providing the first spatio‐temporal distribution of LiO2 and revealing its reversed diffusion trajectories at limited electron transport. The synergistic combination of experiments and models identifies the crucial role of channel sizes on mechanisms that are divided into mass, hybridization, and electron transport control. For macropores, improving Li2O2 conductivity and mitigating solid‐liquid interface damage are urgent compared to enhancing oxygen diffusion. The unit model offers a promising approach to quantitatively understand the reaction and transport mechanisms in other battery systems with porous electrodes. This work represents a break through in knowledge of control mechanisms and guides the design of disordered electrodes for high‐performance lithium–oxygen batteries. [ABSTRACT FROM AUTHOR]

Single‐atom catalysts (SACs) have been widely explored as additives to improve the performance of lithium–sulfur (Li–S) batteries, however, the design of highly catalytic and in‐depth knowledge of the structure–activity relationship of SACs remains a huge challenge. Herein, electron redistribution of the Co site by introducing the S atom to replace the N atom in the first coordination shell is theoretically predicted to enhance the anchoring capability of lithium polysulfides (LiPSs) and simultaneously facilitate the redox process of Li–S batteries, due to the strengthened d‐p orbital hybridization between sulfur species and SACs compared with the traditional CoN4 architecture. Enlightened by theoretical analysis, asymmetric (N, S) coordinated Co single atoms embedded on N, S‐doped hierarchically porous carbon (S‐Co‐SACs/NSC) is precisely designed and constructed as a high‐efficiency fixity and catalyst for Li–S batteries. Therefore, the battery with S@S‐Co‐SACs/NSC cathode exhibits high areal capacity and cycling stability. This work highlights the vital function of the electronic structures of SACs in promoting the practical application of Li–S batteries. [ABSTRACT FROM AUTHOR]

Poor oxidation resistance limits the further application of Nb 4 AlC 3 MAX phase, a high-temperature structural candidate material. Transition metal doping can significantly address this problem. In this paper, we investigated the oxidation mechanism of the Nb 4 AlC 3 (0 0 0 1) surface with Ti doping by combining density functional theory (DFT) and ab initio molecular dynamics (AIMD). DFT results indicate that the Nb surface has a lower surface energy, making it more easily exposed and reactive towards O 2 molecules. O atoms are expected to preferentially occupy the HCP and FCC hollow sites on the surface. The Ti-doped surface has a stronger adsorption capacity for O atoms. O atoms gain electrons, while Nb/Ti atoms lose electrons. The formation of O–Nb/Ti bonds is facilitated by the hybridization of O-p and Nb/Ti-d orbitals. And O–Ti bonds are more stable than O–Nb bonds. AIMD simulation results show that O 2 molecules on the clean and doped surfaces gradually dissociate into O atoms over time. These O atoms then combine with surface atoms to form Nb oxides, Ti oxides, and Nb–Ti oxides. With the passage of time, the concentration of Ti oxides increases while that of Nb oxides decreases. And the oxidation rate at 1073K is higher. The O–Nb/Ti bond population gradually increases over time, indicating that the bonding between O atoms and the surface is slowly strengthened. This study provides fundamental insights into the oxidation mechanism of transition metal-doped 413 MAX phase Nb 4 AlC 3 surfaces. [ABSTRACT FROM AUTHOR]

Solar‐to‐chemical energy conversion under weak solar irradiation is generally difficult to meet the heat demand of CO2 reduction. Herein, a new concentrated solar‐driven photothermal system coupling a dual‐metal single‐atom catalyst (DSAC) with adjacent Ni−N4 and Fe−N4 pair sites is designed for boosting gas‐solid CO2 reduction with H2O under simulated solar irradiation, even under ambient sunlight. As expected, the (Ni, Fe)−N−C DSAC exhibits a superior photothermal catalytic performance for CO2 reduction to CO (86.16 μmol g−1 h−1), CH4 (135.35 μmol g−1 h−1) and CH3OH (59.81 μmol g−1 h−1), which are equivalent to 1.70‐fold, 1.27‐fold and 1.23‐fold higher than those of the Fe−N−C catalyst, respectively. Based on theoretical simulations, the Fermi level and d‐band center of Fe atom is efficiently regulated in non‐interacting Ni and Fe dual‐atom pair sites with electronic interaction through electron orbital hybridization on (Ni, Fe)−N−C DSAC. Crucially, the distance between adjacent Ni and Fe atoms of the Ni−N−N−Fe configuration means that the additional Ni atom as a new active site contributes to the main *COOH and *HCO3 dissociation to optimize the corresponding energy barriers in the reaction process, leading to specific dual reaction pathways (COOH and HCO3 pathways) for solar‐driven photothermal CO2 reduction to initial CO production. [ABSTRACT FROM AUTHOR]

Electrochemically converting waste nitrate (NO3−) into ammonia (NH3) is a green route for both wastewater treatment and high‐value‐added ammonia generation. However, the NO3−‐to‐NH3 reaction involves multistep electron transfer and complex intermediates, making it a grand challenge to drive efficient NO3− electroreduction with high NH3 selectivity. Herein, an in‐operando electrochemically synthesized Cu2O/NiO heterostructure electrocatalyst is proven for efficient NH3 electrosynthesis. In situ Raman spectroscopy reveals that the obtained Cu2O/NiO, induced by the electrochemistry‐driven phase conversion, is the real active phase. This electronically coupled phase can modulate the interfacial charge distribution, dramatically lower the overpotential in the rate‐determining step and thus requiring lower energy input to proceed with the NH3 electrosynthesis. The orbital hybridization calculations further identify that Cu2O is beneficial for NO3− adsorption, and NiO could promote the desorption of NH3, forming an excellent tandem electrocatalyst. Such a tandem system leads to NH3 Faradaic efficiency of 95.6%, a super‐high NH3 selectivity of 88.5% at −0.2 V versus RHE, surpassing most of the NH3 electrosynthesis catalysts at an ultralow reaction voltage. [ABSTRACT FROM AUTHOR]

We present an alternative technique for estimating the response of a cold atom interferometer (CAI). Using data from a conventional inertial measurement unit (IMU) and common strapdown terminology, the position of the atom wave packet is tracked in a newly introduced sensor frame, enabling hybridization of both systems in terms of acceleration and angular rate measurements. The sensor frame allows for an easier mathematical description of the CAI measurement and integration into higher-level navigation systems. The dynamic terms resulting from the transformation of the IMU frame into the CAI sensor frame are evaluated in simulations. The implementation of the method as a prediction model in an extended Kalman filter is explained and demonstrated in realistic simulations, showing improvements of over two orders of magnitude with respect to the conventional IMU strapdown solution. Finally, the implications of these findings for future hybrid quantum navigation systems are discussed. [ABSTRACT FROM AUTHOR]

Novel quantum materials have broad application prospects in spintronic devices and low‐power‐consumption devices. The kagome‐type lattice has special corner‐sharing triangle geometry, providing a rich platform to investigate the relationship of novel correlated topological states, geometry, and strong electron interactions. However, the orbital hybridization in the presence of flat band that originated from the electron localization due to the unique kagome lattice configuration is still unclear. Resonant‐angle‐resolved photoemission spectroscopy is utilized to study the valence band structures of a new vanadium‐based kagome material GdV6Sn6, combined with density functional theory calculation. Herein, a significant hybridization between V 3d and Sn 5p electrons, which paves the way to understand the formation of long‐range magnetic ordering of GdV6Sn6 and other kagome materials at low temperature, is unambiguously revealed in the results. [ABSTRACT FROM AUTHOR]

The electrochemical N2 oxidation reaction (NOR) has emerged as a promising approach for achieving high selectivity in nitric acid (HNO3) production. However, the sluggish N2 activation process in NOR due to the high cleavage energy barrier of the N≡N bond remains a challenge. Herein, a novel orbital hybridization strategy for tuning the NOR performance through the construction of cerium (Ce) 4f–O 2p–Co 3d network in Ce‐doped Co3O4 (Ce–Co3O4) is proposed. The Ce–Co3O4 catalyst exhibits an enhanced HNO3 yield of 24.76 µg h−1 mgcat−1 and a promoted Faradaic efficiency of 31.93% in 0.1 m Na2SO4 electrolyte under ambient conditions compared to those of the pure Co3O4 (13.75 µg h−1 mgcat−1 and 23.43%). Density functional theory caculations demonstrate the strong 4f–2p–3d orbital hybridization and electron transfer in Ce–Co3O4. Moreover, a series of in situ techniques provide direct evidence of stronger adsorption peaks for Co─N bond and the key intermediate *NO formed after N2 activation on the surface of Ce–Co3O4. This work provides a promising route for the preparation of efficient NOR catalysts and sheds light on the mechanism of N2 activation through orbital hybridization. [ABSTRACT FROM AUTHOR]

[Display omitted] The oxygen evolution reaction (OER) has garnered considerable attention because of its promising prospects in electrochemical energy conversion applications, but a significant challenge is faced by the insufficient understanding of sluggish OER kinetics. In fact, the intrinsic "acceptance-donation" process of electrons between active sites and reactants is responsible for improving OER activity. Herein, we suggest a multielement hybridization strategy to rematch spin electron occupation and energy splitting in high-entropy perovskites with multiple orbital coordination. In this concept, electronic hopping between t 2g and e g orbitals among particular catalytic sites can be obviously enforced due to introducing more favorable energy levels from neighboring metal sites, which can demonstrate multistage orbital hybridization reaction activity. As a result, our proposed multistage-hybridized high-entropy perovskites display an impressive activity of 199.8 mA cm−2 as an overpotential of ∼0.46 V, which is ∼5.3 times that of pristine perovskite. Different from traditional catalyst designs, this study focuses on multistage orbital hybridization and electron exchange interactions through a multisite coordination mechanism to construct a fast reaction pathway. Our findings provide a new strategy for accelerating OER catalytic kinetics. [ABSTRACT FROM AUTHOR]

Based on first-principle calculations using density functional theory, the effects of alternate substituting of Fe, Ru, Os, Co, and Ni on the magnetic properties of the silicone system were investigated, and the stability, charge density, electronic structure, and optical properties of the system were analyzed. The results show that all the substituting systems show subferromagnetic properties except for the Ru atom–substituting silicone system which shows magnetic quenching and exhibits paramagnetism. Within the current study, the substituting of Fe, Ru, Os, Co, and Ni atoms does not change the metallic properties of silicone. Comparing the four substituting atoms of Fe, Os, Co, and Ni, it is revealed that the magnetic moment of the Fe-, Os-, and Co-substituting silicone system is mainly provided by the dopant atoms, and the magnetic moment of the Ni-substituting system is not contributed by the Ni atoms, but by the Si atoms in the silicone that are not covalently bonded to the Ni atoms induced by the dopants. The possible reason for the paramagnetic properties of Ru atom–substituting silicone systems is the strong hybridization and resonance between the dopant Ru atom and Si atom orbitals, which leads to the formation of stable covalent bonds between Ru–Si and quenching of the orbital magnetic moment. The magnetic properties induced by the transition metal can enhance the light absorption intensity and have an effect on the photocatalytic activity. [ABSTRACT FROM AUTHOR]

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Under environmental conditions, electrochemical nitrogen reduction reaction (NRR), which has the advantages of low energy consumption, zero CO 2 emissions, green and sustainability, is considered to be an alternative to the Haber-Bosch method for ammonia synthesis. However, the practical application of NRR is hindered by the poor N 2 adsorption capacity, low NH 3 synthesis efficiency, and poor selectivity of the catalyst. In this paper, from a theoretical point of view, we design a Mo-based catalyst with multiple active sites based on B-modified 2D CCFs. The B atom has a similar N 2 activation mechanism to transition metal atoms in that their empty orbitals (sp3, d orbitals) can accept lone pairs of electrons of nitrogen and feedback electrons to the anti-bond orbitals of the NˆN bond. Moreover, the addition of the B atom leads to new orbital hybridization and charge distribution, which strengthens the N 2 adsorption capacity and reduces the energy change, thereby improving the NRR catalytic activity. After a series of analyses, it is concluded that MoZr-BPc CCF catalyst has the best NRR activity with the minimum limiting potential of −0.36 V, the overpotential of 0.20 V, and FE NRR of 100%, and it can well inhibit the HER extremely. The synergistic effect of non-metallic and metal atoms provides a new idea for the rational design of NRR electrocatalysts and lays a theoretical foundation for the widespread use of NRR in practical applications. • The 2D CCFs are the superior platforms for designing NRR electrocatalysts. • The addition of B atom leads to new orbital hybridization and charge distribution. • MoZr-BPc CCF exhibits the lowest limiting potential and the highest NRR selectivity. [ABSTRACT FROM AUTHOR]

Highly efficient hydrogen evolution reaction (HER) electrocatalyst will determine the mass distributions of hydrogen‐powered clean technologies, while still faces grand challenges. In this work, a synergistic ligand modulation plus Co doping strategy is applied to 1T−MoS2 catalyst via CoMo‐metal‐organic frameworks precursors, boosting the HER catalytic activity and durability of 1T−MoS2. Confirmed by Cs corrected transmission electron microscope and X‐ray absorption spectroscopy, the polydentate 1,2‐bis(4‐pyridyl)ethane ligand can stably link with two‐dimensional 1T−MoS2 layers through cobalt sites to expand interlayer spacing of MoS2 (Co−1T−MoS2‐bpe), which promotes active site exposure, accelerates water dissociation, and optimizes the adsorption and desorption of H in alkaline HER processes. Theoretical calculations indicate the promotions in the electronic structure of 1T−MoS2 originate in the formation of three‐dimensional metal‐organic constructs by linking π‐conjugated ligand, which weakens the hybridization between Mo‐3d and S‐2p orbitals, and in turn makes S‐2p orbital more suitable for hybridization with H‐1s orbital. Therefore, Co−1T−MoS2‐bpe exhibits excellent stability and exceedingly low overpotential for alkaline HER (118 mV at 10 mA cm−2). In addition, integrated into an anion‐exchange membrane water electrolyzer, Co−1T−MoS2‐bpe is much superior to the Pt/C catalyst at the large current densities. This study provides a feasible ligand modulation strategy for designs of two‐dimensional catalysts. [ABSTRACT FROM AUTHOR]

Graphdiyne (GDY), a new two-dimensional (2D) carbon hybrid material, has attracted much attention because it can function as both an electron donor and acceptor and possesses a certain intrinsic band gap due to its unique sp and sp2 conjugate hybridization. In this study, a new method has been developed for the low-cost and high-yield production of GDY and hydrogen-substituted graphdiyne (H-GDY). This new one-pot conjugation method offers several advantages over traditional cross-coupling methods and mechanical methods, including simpler steps and lower risk. The experiments on the synthesis of different halogenated benzene precursors demonstrate that GDY and H-GDY can be directly synthesized using a simple one-pot method with obvious universality. XRD, SEM mapping, XPS and TEM analyses reveal the presence of SiO2 and SiC in the GDY and H-GDY obtained through the one-pot conjugation method. The sources of SiO2 and SiC are analyzed. Based on all the experimental results, it is observed that introducing fluorine in the one-pot conjugation method leads to the formation of CaF2 which affects the photocatalytic activity of H-GDY and GDY. [ABSTRACT FROM AUTHOR]

[Display omitted] Pollution control of As(III), a naturally occurring carcinogen, has recently gained a global attention, while due to the dominance of neutral H 3 AsO 3 over a wide pH range, As(III) immobilization by most minerals is not efficient as As(V) immobilization. TiO 2 shows promise for controlling As(III) pollution, and herein, a comprehensive study about As(III) adsorption by TiO 2 and oxyanion formation is conducted by means of DFT + D3 methods. Both anatase and rutile are effective for As(III) adsorption, while As(III) adsorption affinities differ significantly and are −1.48 and −3.79 eV for pristine surfaces, ascend to −3.85 and −5.08 eV for O vacancies, and further to −5.37 and −5.26 eV for Ti vacancies, respectively. The bidentate binuclear complexes dominate for pristine surfaces, and O vacancies prefer O As insertion into TiO 2 lattice, while for Ti vacancies, all As(III) centers are auto-oxidized to As(V). Ti-3d, O-2p or/and As-4p rather than other orbitals contribute significantly to As adsorption, and O and Ti vacancies promote adsorption through stronger orbital hybridization. The superior adsorption for Ti vacancies originates from As(V) formation instead of bonding interactions. The formation of As oxyanions, which may occur spontaneously at pristine surfaces and is greatly promoted by O and Ti vacancies, enhances As(III) adsorption pronouncedly and becomes a viable strategy for As(III) immobilization. H 2 AsO 3 - and HAsO 3 2- dominate for pristine surfaces and O vacancies, and for Ti vacancies, H 2 AsO 4 - and HAsO 4 2- dominate over anatase whereas AsO 4 3- also makes an important contribution over rutile. Results rationalize experimental observations available, and provide significantly new insights about the migration, bioavailability and fate of As(III) over TiO 2 surfaces that facilitate the exploration of scavengers for As and other pollutants. [ABSTRACT FROM AUTHOR]

ZnIn 2 S 4 /ZnO heterostructures have been synthesized by a simple one-step hydrothermal synthesis method, which lead to ZnO grow on the surface of ZnIn 2 S 4 nanosheets, forming a strong electronic interaction between the two semiconductors. Under the full spectrum irradiation, the optimal photocatalyst 2ZnIn 2 S 4 /ZnO shows the H 2 evolution rate of 13,638 (water/ethanol = 1:1) and 3036 (water) μmol•g−1h−1, which is correspondingly 4 and 5 times higher than that of pure ZnIn 2 S 4. ISI-XPS analysis and DFT calculations show that electrons are transferred from ZnIn 2 S 4 to ZnO through hybridization and an internal electric field (IEF) is formed between ZnIn 2 S 4 and ZnO. The improvement of photocatalytic performance can be attributed to the effect of internal electric field, the increase of photo-generated electron and hole transport rate, the suppression of charge carrier recombination, and the enhancement of light collection. The photoelectrochemical and EPR results show that a stepped (S-scheme) heterojunction is formed in the ZnIn 2 S 4 /ZnO redox center, which greatly promotes separation of electron-hole pairs to promote efficient hydrogen evolution. This work provides a new strategy for the design of S-scheme photocatalytic systems for hydrogen evolution. [Display omitted] ZnIn 2 S 4 /ZnO heterostructures have been achieved by a simple in-situ growth solvothermal method. Under full spectrum irradiation, the optimal photocatalyst 2ZnIn 2 S 4 /ZnO exhibits H 2 evolution rate of 13,638 (water/ethanol = 1:1) and 3036 (water) μmol·g−1h−1, which is respectively 4 and 5 times higher than that of pure ZnIn 2 S 4. In situ illumination X-ray photoelectron spectroscopy (ISI-XPS) analysis and density functional theory (DFT) calculations show that the electrons of ZnIn 2 S 4 are removed to ZnO through hybridization and form an internal electric field between ZnIn 2 S 4 and ZnO. The optical properties of the catalyst and the effect of internal electric field (IEF) can increase photo-generated electrons (e−)–holes (h+) transport rate and enhance light collection, resulting in profitable photocatalytic properties. The photoelectrochemical and EPR results show that a stepped (S-scheme) heterojunction is formed in the ZnIn 2 S 4 /ZnO redox center, which greatly promotes separation of e−–h+ pairs and efficient H 2 evolution. This research offers an effective method for constructing an efficient S-Scheme photocatalytic system for H 2 evolution. [ABSTRACT FROM AUTHOR]

Improving catalytic activity without loss of catalytic stability is one of the core goals in search of low‐iridium‐content oxygen evolution electrocatalysts under acidic conditions. Here, we synthesize a family of 66 SrBO3 perovskite oxides (B=Ti, Ru, Ir) with different Ti : Ru : Ir atomic ratios and construct catalytic activity‐stability maps over composition variation. The maps classify the multicomponent perovskites into chemical groups with distinct catalytic activity and stability for acidic oxygen evolution reaction, and highlights a chemical region where high catalytic activity and stability are achieved simultaneously at a relatively low iridium level. By quantifying the extent of hybridization of mixed transition metal 3d‐4d‐5d and oxygen 2p orbitals for multicomponent perovskites, we demonstrate this complex interplay between 3d‐4d‐5d metals and oxygen atoms in governing the trends in both activity and stability as well as in determining the catalytic mechanism involving lattice oxygen or not. [ABSTRACT FROM AUTHOR]

The key issue in the 5‐hydroxymethylfurfural oxidation reaction (HMFOR) is to understand the synergistic mechanism involving the protons deintercalation of catalyst and the adsorption of the substrate. In this study, a Pd/NiCo catalyst was fabricated by modifying Pd clusters onto a Co‐doped Ni(OH)2 support, in which the introduction of Co induced lattice distortion and optimized the energy band structure of Ni sites, while the Pd clusters with an average size of 1.96 nm exhibited electronic interactions with NiCo support, resulting in electron transfer from Pd to Ni sites. The resulting Pd/NiCo exhibited low onset potential of 1.32 V and achieved a current density of 50 mA/cm2 at only 1.38 V. Compared to unmodified Ni(OH)2, the Pd/NiCo achieved an 8.3‐fold increase in peak current density. DFT calculations and in situ XAFS revealed that the Co sites affected the conformation and band structure of neighboring Ni sites through CoO6 octahedral distortion, reducing the proton deintercalation potential of Pd/NiCo and promoting the production of Ni3+−O active species accordingly. The involvement of Pd decreased the electronic transfer impedance, and thereby accelerated Ni3+−O formation. Moreover, the Pd clusters enhanced the adsorption of HMF through orbital hybridization, kinetically promoting the contact and reaction of HMF with Ni3+−O. [ABSTRACT FROM AUTHOR]

The electronic properties in particular the occupation number of 5f electrons and the valence state of Am ions in americium trichloride (AmCl3) are studied by using density functional theory (DFT) merged with dynamical mean‐field theory (DMFT). We find that j = 5/2, j = 7/2 manifolds both are in the insulating regimes, resulting in the semiconducting band gap of about 0.837 eV, together with the weak Am 5f‐conduction electrons hybridization and the localized 5f‐derived spectra feature in the vicinity of the Fermi level. The weighted summation for the occupation probabilities of 5fn (n = 3–7) atomic configurations suggests that 5f electrons have the inter‐configuration fluctuation with an average occupation number of 5f electrons n5f ~ 5.182, corresponding to the valence state of Am3.818+ in AmCl3. The 5fn‐mixing‐driven inter‐configuration fluctuation might originate from the complicated quantum mechanics processes such as the dual nature of 5f electrons and the flexible electronic configuration of Am ions. Finally, the so‐called quasiparticle band structure is also predicted. [ABSTRACT FROM AUTHOR]

[Display omitted] • The interaction mechanisms between Cd/Pb and kaolinite surfaces are explored. • The adsorption stability on the -H + Fe surface follows CdCl 2 < PbCl 2 < Cd0 < Pb0. • The electronic structure is analyzed from charge transfer and chemical bonding. • The active sites on the -H + Fe surface are the O atoms close to the Fe atom. Incineration of organic solid wastes is accompanied by the heavy metal emission through flue gas. As an inexpensive and efficient heavy metal adsorbent, the improvement of kaolinite adsorption performance for heavy metals has drawn widespread interests. In this work, the interaction mechanisms between various kaolinite surfaces and Cd/Pb species are explored through first principles calculations. The results show that the combination of Fe doping and dehydroxylation enhances the activity of kaolinite surfaces, analysis of adsorption configurations reveal that both Cd and Pb species are immobilized through chemisorption on the -H + Fe surface. At the microscopic level, further electronic structure analysis shows that the composite modified kaolinite surface has more electron transfer and more pronounced orbital hybridization and overlap compared to the original kaolinite surface, demonstrating that the modification means of dehydroxylation and Fe doping indeed enhanced the activity of the kaolinite surface, especially the activity of the O atoms in the vicinity of the Fe atom and that the O atoms are more efficiently bonded as ionic connecting Cd/Pb species for the purpose of trapping Cd/Pb species. This study points out the research direction and provides basic theoretical support for the development of new kaolinite adsorbents in the future. [ABSTRACT FROM AUTHOR]

In this research, the single-phase tetragon NdMn2-xAgxSi2 (0 ≤ x ≤ 0.4) alloys were prepared. It was found that the phase transition temperature was decreased by evaluating Ag substitution, which was attributed to the enhancement of orbital hybridization. The thermomagnetic hysteresis disappears for x ≥ 0.2. For Δμ0H of 0–7 T, the values of the maximum magnetic entropy change (the relative cooling power) are 22.2 J/kgK (420.7 J/kg), 20.1 J/kgK (500.5 J/kg), 19.9 J/kgK (552.8 J/kg) and 12.0 J/kgK (300.0 J/kg) in NdMn2-xAgxSi2 (x = 0, 0.2, 0.3 and 0.4) alloys. The XPS valence band spectra indicate that the density of electron and the hybridization effect is enhanced by increasing the substitution amount of Ag. This is attributed to the fact that the atomic radius of Ag is larger than that of Mn, resulting in the strengthening of the covalent bond between Ag and Si. [ABSTRACT FROM AUTHOR]

Mo13 is a magic number cluster of Mon and can effectively activate N2 in ammonia synthesis, but its ground-state structure is not determined. The possible stable isomers of Mo13 are obtained by using global searching method (genetic algorithm) and further optimized at the level of BP86/def2-TZVP. The results indicate that Mo13 prefers to adopt open or layer-type structures due to the stronger 4d-5 s orbital hybridization. The most stable structure of Mo13 is a seriously deformed icosahedron and it is nearly degenerated in energies with the isomer of cage-like one. Both these two isomers are with high stabilities, and thus the electronic structures, bonding characters, spectral properties, reactive activities and the external filed response for these two isomers are systematically explored. This work provides many important information for distinguishing these two isomers. [ABSTRACT FROM AUTHOR]

The sensing behaviors of monolayer antimonide phosphorus (SbP) for air pollutants (CO, CO2, H2S, SO2 NO, NO2 and NH3) are studied by using the density functional theory. In this paper, we computed the adsorption energy, charge transfer, adsorption distance, band gap, electronic structure and recovery time of gas molecules on monolayer SbP. The calculated results indicate that monolayer SbP is sensitive to SO2, NO and NO2 molecules via strong physical interaction. Through the analysis of charge transfer, it could be seen that there were more charges transfer of NO (0.549e), NO2 (− 0.366e) and SO2 (− 0.263e) gas molecules than other gases. When SO2, NO and NO2 gas molecules are adsorbed on the monolayer SbP, the band structure was reduced apparently. In particular, for NO2 adsorption, impurity bands pass through the Fermi surface, making the system appear semimetallic properties. Furthermore, the adsorption of NO and NO2 can cause obvious deviation in the DOS. On further analysis, we knew that these changes were mainly due to the orbital hybridization between the p orbitals of N, O and S atoms and the p orbitals of Sb and P atoms. Theoretical studies show that monolayer SbP may be a potential gas sensing material for SO2, NO and NO2 gas molecules. [ABSTRACT FROM AUTHOR]

The exploitation of new hydrogen storage materials with high-capacity and reversible performance could play a very important role in the large-scale utilization of hydrogen as an energy source. The hydrogen storage performances of Li and Ca atoms decorated as well as Li/Ca co-decorated VO2 monolayer system were comprehensively investigated based on first-principles calculations. The metal atoms are stably adsorbed on the surface of the VO2 monolayer without forming metal clusters. Three and six hydrogen molecules can be absorbed by a Li atom and Ca atom, respectively, and its average adsorption energy is larger than 0. 20 eV/H2. Charge density differences and density of states of H2 adsorbed systems were analyzed, and the results reveal that both the polarization mechanism and orbital hybridization are responsible for the adsorption of hydrogen molecules. The hydrogen storage capacity of the Li-decorated system increases with the increase of Li coverage, while that of Ca-decorated system is high only in lower Ca coverage. Moreover, Li / Ca co-decoration can effectively increase the hydrogen storage capacity of the system, its hydrogen storage mass density is 5. 00% (mass fraction). Finally, the influence of temperature and pressure on the stability of hydrogen adsorption system is studied. [ABSTRACT FROM AUTHOR]

Mo13 is a magic number cluster of Mon and can effectively activate N2 in ammonia synthesis, but its ground-state structure is not determined. The possible stable isomers of Mo13 are obtained by using global searching method (genetic algorithm) and further optimized at the level of BP86/def2-TZVP. The results indicate that Mo13 prefers to adopt open or layer-type structures due to the stronger 4d-5 s orbital hybridization. The most stable structure of Mo13 is a seriously deformed icosahedron and it is nearly degenerated in energies with the isomer of cage-like one. Both these two isomers are with high stabilities, and thus the electronic structures, bonding characters, spectral properties, reactive activities and the external filed response for these two isomers are systematically explored. This work provides many important information for distinguishing these two isomers. [ABSTRACT FROM AUTHOR]

Novel Ag3PO4/Bi2WO6 catalysts with enhanced visible-light performance were synthesized using a hydrothermal method and characterized to investigate their morphology, microscopic structure, and binding energies. Photoluminescence spectrum (PL) and electrochemical impedance spectroscopy (EIS) data demonstrate that the formed Ag3PO4/Bi2WO6 heterojunction effectively promotes hole (h+)–electron (e−) separation and transfer efficiency, resulting in the enhancement of photocatalytic activity. Ag3PO4/Bi2WO6 displays higher photocatalytic activity than pure Bi2WO6 or Ag3PO4 alone. Photogenerated holes (h+), ·O2−, and ·OH were found to be the main active species for the degradation of malachite green (MG), methylene blue (MB), and Rhodamine B (RhB). The DFT calculation explains the photostability of Ag3PO4/Bi2WO6 from the perspective of electronic structure. The bandgap of Ag3PO4/Bi2WO6 between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) is 1.41 eV, compared with that of Ag3PO4 at 0.91 eV and Bi2WO6 at 2.59 eV. Ag–O–Bi hybridization and the wide HOMO–LUMO bandgap lead to difficulty in electron transfer. As a consequence, Ag+ is difficult to obtain electrons and difficult to convert into Ag0, which makes the catalyst stable. [ABSTRACT FROM AUTHOR]

The realization of the spin Hall effect has opened new frontiers for the design of efficient memory storage devices facilitated by the conversion of charge currents to spin currents. Here, using the Kubo formula, we calculate the intrinsic spin Hall conductivity (SHC) of orthorhombic tin selenide (o-SnSe) under the influence of isotropic compressive strain in the ab-plane. As the strain is gradually increased, we obtain a substantial hybridization between the pz orbitals of Sn and Se atoms of an electron pocket from the lowest conduction band and the topmost valence band, respectively. This hybridization process greatly enhances the SHC at the Fermi level and charge-to-spin conversion efficiency, the latter of which is superior to that of popular transition metals such as Ta and Pt. This makes strained o-SnSe an attractive candidate for use in spintronic devices. [ABSTRACT FROM AUTHOR]

Metal-boron triple bonds are rare due to the electron deficiency of boron. This study uncovers a simple electron-precise metal boryne complex, [Bi≡BH]−, which is produced within an ion trap through chemical reactions of the open-shell BiB− anion with H2. Photoelectron imaging is used to investigate the electronic structure and chemical bonding of the BiBH− complex. The B atom in the linear closed-shell BiBH− is found to undergo sp hybridization, forming a B–H single bond and a Bi≡B triple bond. Photoelectron imaging reveals three detachment transitions from the BiBH− (1Σ+) anion to the neutral BiBH, including the ground state (2Π3/2) and two excited states (2Σ+ and 2Π1/2). Strong vibronic coupling is observed between the 2Π3/2 and 2Σ+ states, evidenced by the appearance of bending vibrations and their unique photoelectron angular distributions. The BiBH− complex not only stands as the simplest metal boryne complex, but also serves as an ideal molecular system to investigate both spin–orbit and vibronic couplings. [ABSTRACT FROM AUTHOR]

Metal-boron triple bonds are rare due to the electron deficiency of boron. This study uncovers a simple electron-precise metal boryne complex, [Bi≡BH]−, which is produced within an ion trap through chemical reactions of the open-shell BiB− anion with H2. Photoelectron imaging is used to investigate the electronic structure and chemical bonding of the BiBH− complex. The B atom in the linear closed-shell BiBH− is found to undergo sp hybridization, forming a B–H single bond and a Bi≡B triple bond. Photoelectron imaging reveals three detachment transitions from the BiBH− (1Σ+) anion to the neutral BiBH, including the ground state (2Π3/2) and two excited states (2Σ+ and 2Π1/2). Strong vibronic coupling is observed between the 2Π3/2 and 2Σ+ states, evidenced by the appearance of bending vibrations and their unique photoelectron angular distributions. The BiBH− complex not only stands as the simplest metal boryne complex, but also serves as an ideal molecular system to investigate both spin–orbit and vibronic couplings. [ABSTRACT FROM AUTHOR]

N-rich La–N compounds have been studied by first-principles calculations in this work. We identified nine unknown polynitrides, which reveals that the miraculous ligand effect of La plays an important role in the electronic properties and hybridization of nitrogen atoms. Unique tri-coordination atoms with alternate sp2 and sp3 hybridizations are formed in the N18 ring of LaN8. The ligand effect of La induces a novel 1-D chain-like N10 cage polymeric structure in LaN10 and stabilizes it under mild pressure (25 GPa). Moreover, the ligand effect of the introduced La atom on the N10 cage has been clarified by the analysis of the structural evolution behavior from I4¯3m-N10 to Imm2-LaN10. In addition, Imm2-LaN10 with excellent energy (4.56 kJ g−1) and explosive performance (Vd = 16.88 km s−1, Vp = 1887.53 kbar) is a good energetic material candidate. [ABSTRACT FROM AUTHOR]

An anomalously high valence state sometimes shows up in transition-metal oxide compounds. In such systems, holes tend to occupy mainly the ligand p orbitals, giving rise to interesting physical properties such as superconductivity in cuprates and rich magnetic phases in ferrates. However, no one has ever observed the distribution of ligand holes in real space. Here, a successful observation of the spatial distribution of valence electrons in cubic perovskite SrFeO3 by high-energy X-ray diffraction experiments and precise electron density analysis using a core differential Fourier synthesis method is reported. A real-space picture of ligand holes formed by the orbital hybridization of Fe 3d and O 2p is revealed. The anomalous valence state in Fe is attributed to the considerable contribution of the ligand hole, which is related to the metallic nature and the absence of Jahn-Teller distortions in this system. [ABSTRACT FROM AUTHOR]

Shuttle effect and sluggish redox kinetics of sulfur species still hinder the practical application of lithium‐sulfur batteries (LSBs). Herein, a strategy of integrating sub‐nano catalysts into metal‐organic framework (MOF) is proposed for developing efficient sulfur host to tackle these issues. The designed MOF host (MOF‐TOC) endowed with sub‐nano TiO clusters (TOCs) in the mesopores of MOF can act as an efficient reaction chamber in LSBs. Systematic electrochemical measurements and calculations demonstrate that MOF‐TOC can trap and confine lithium polysulfides (LiPSs) via strong chemical interaction. Moreover, the highly active TOCs isolated in different nanopores can accelerate the bidirectional redox reaction of sulfur species through the d‐p orbital hybridization with sulfur species. Benefiting from these merits, MOF‐TOC delivers LSBs with remarkably improved areal capacity and cycling stability at high sulfur loadings and lean electrolytes. This work gives insight into the rational design of catalyst‐containing MOF hosts and will shed light on the development of advanced catalytic hosts for high‐performance LSBs. [ABSTRACT FROM AUTHOR]

Developing high‐performance infrared (IR) radiation materials with desired broadband emissivity, excellent thermal stability, and scalable fabrication processes is highly desirable for energy‐saving applications and heat dissipation. However, it remains a grand challenge to concurrently meet these requirements in existing IR radiation materials. Herein, a high‐entropy (HE) approach is employed to advance the IR radiation performance of spinel oxide. This strategy efficiently narrows the bandgap due to the enhanced electron transitions and the introduction of oxygen vacancies (Ov), variable‐valence behavior, and orbital hybridization. In addition, the lattice distortion effect lowers the symmetry of lattice vibration. Therefore, the resulting HE spinel oxide exhibits near‐blackbody radiation performance, with its emissivity approximately three times higher than that of the binary spinel oxide. Moreover, the entropy‐dominating phase stabilization effect contributes to impressive thermal stability (stable at 1300 °C for 100 h). This makes it suitable for high‐temperature thermal radiation applications, such as energy conservation in industrial high‐temperature furnaces. More importantly, the HE spinel oxide can be readily spray‐coated on various substrates. And the coating on stainless steel reaches an outstanding emissivity of 0.943 in the 0.78−16 µm wavelength range. All these merits render the HE approach competitive for the development of high‐emissivity and thermally stable thermal radiation materials. [ABSTRACT FROM AUTHOR]

The selective activation of C–C bonds holds vast promise for catalysis. So far, research has been primarily directed at rhodium and nickel under harsh reaction conditions. Herein, we report C–C insertion reactions of a 12-electron palladium(0) surrogate stabilized by a cyclic(alkyl)(amino) carbene (CAAC) ligand. Benzonitrile (1), biphenylene (2), benzocyclobutenone (3), and naphtho[b]cyclopropene (4) were studied. These substrates allow elucidation of the effect of ring strain as well as hybridization encompassing sp3, sp2 and sp hybridized carbon atoms. All reactions proceed quantitatively at or below room temperature. This work therefore outlines perspectives for mild C–C bond functionalization catalysis. [ABSTRACT FROM AUTHOR]

An anomalously high valence state sometimes shows up in transition-metal oxide compounds. In such systems, holes tend to occupy mainly the ligand p orbitals, giving rise to interesting physical properties such as superconductivity in cuprates and rich magnetic phases in ferrates. However, no one has ever observed the distribution of ligand holes in real space. Here, a successful observation of the spatial distribution of valence electrons in cubic perovskite SrFeO3 by high-energy X-ray diffraction experiments and precise electron density analysis using a core differential Fourier synthesis method is reported. A real-space picture of ligand holes formed by the orbital hybridization of Fe 3d and O 2p is revealed. The anomalous valence state in Fe is attributed to the considerable contribution of the ligand hole, which is related to the metallic nature and the absence of Jahn-Teller distortions in this system. [ABSTRACT FROM AUTHOR]

Metal nitrides offer great opportunities for improving activity and selectivity of electrocatalytic nitrogen reduction reaction (ENRR) via the lattice nitrogen‐participated mechanism. Understanding the role of local chemistry of lattice nitrogen is important for establishing rational design principles of nitride catalysts. Herein, high‐throughput theoretical calculations are employed to investigate lattice nitrogen‐participated ENRR over a family of antiperovskite nitrides (M′M3N, M and M′ are different metal atoms) with highly tunable surrounding environments of N atoms. The M′M3N structure comprises isolated N atoms in the center, M atoms in the first coordination shells, and M′ atoms in the second coordination shells. An appropriate M‐N bond strength is found to be crucial for designing ideal nitride catalysts. Specifically, weak M‐N bonding facilitates the participation of lattice nitrogen and better activity, but too weak M‐N bonding results in structural instability of antiperovskite. The type of M element governs M‐N bond strength through adjusting hybridization interactions between M orbital and N orbital, and the M′ element can further finely regulate M‐N bond strength via M‐M′ polarization effects. Finally, AgBa3N, AlBa3N, GaBa3N catalysts are screened to possess greater ENRR activity than the benchmarking Ru (0001) catalysts and high selectivity toward hydrogen evolution reaction. [ABSTRACT FROM AUTHOR]

The development of excellent catalysts with high reactive activity remains a significant challenge for overcoming the sluggish oxygen evolution reaction (OER). Different from other catalysts, herein, a feasible Li intercalation strategy is suggested to regulate the spin‐resolved electronic structures of 2D‐layered IrO2 nanostructures for improving their reactive activity. When some Li ions are intercalated into the layered IrO2 materials, the spin splitting at Ir‐5d orbitals occurs, leading to an obvious reduction in the relative activation energies at OER. The detailed analysis about spin‐resolved electronic structures demonstrates that the intercalated Li ions can provide some 1s electrons to the O‐2p orbitals via a weak bonding interaction, for which the electronic occupation at Ir‐5d orbitals becomes asymmetric, giving rise to a spin polarization. More interestingly, the catalytic activity is enhanced with Li‐intercalation concentration. Herein, a new door is opened to improve OER performance by an intriguing indirect orbital hybridization. [ABSTRACT FROM AUTHOR]

Transition metal oxide materials are promising oxygen catalysts that are alternatives to expensive and precious metal-containing catalysts. Integration of transition metal oxides with high activity for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is an important pathway for good bifunctionality. In contrast to the conventional physical mixing and hybridization strategies, perovskite-type oxide provides an ideal structure for the integration of the transition metal element atoms on an atomic scale. Herein, B-site ordered double-perovskite-type La1.6Sr0.4MnCoO6 nanocrystallites with ultra-small cubic (20–50 nm) morphology and high specific surface areas (25 m2 g−1) were proposed. Rational designs were integrated to promote the ORR-OER catalysis, e.g., introducing oxygen vacancies via A-site cation substitution, further increasing surface oxygen vacancies via integration of a small amount of Pt/C and nanosizing of the material via a facile molten-salt method. The batteries with the La1.6Sr0.4MnCoO6 nanocrystallites and an aqueous alkaline electrolyte demonstrate decent discharge−charge voltage gaps of 0.75 and 1.10 V at 1 and 30 mA cm−2, respectively, and good cycling stability of 250 h (1500 cycles). A coin-type battery with a gel−polymer electrolyte also presents a good performance. [ABSTRACT FROM AUTHOR]

We report the photoluminescence (PL) properties of Eu3+ doped HfO2 nanoparticles prepared using co-precipitation method and annealed at 600 °C. X-ray diffraction results revealed the monoclinic phase in undoped HfO2 and show mixed phase formation at lower concentration and a dominant cubic phase achieved at 5 mol% doping of Eu in HfO2. The phase transition anticipated by the density functional theory is in excellent agreement with experimental findings. The oxygen K-edge XANES spectra clearly depicts the diverse hybridization of O 2p orbitals in M–O7 (for monoclinic) and M–O8 (for cubic) polyhedra of HfO2. Hf L-edge XANES confirms Hf4+ ions in cubic and monoclinic structured HfO2. The Eu3+ ions are dominantly present in the Eu-doped HfO2 nanoparticles. PL study demonstrates the emission in red region with high color purity under different excitation wavelengths from near UV to blue light. PL emission spectra show four emission bands at 594 nm, 609 nm, 650 nm, and 716 nm corresponding to 4f–4f transitions of Eu3+ under excitation wavelengths of 361 nm, 383 nm, 394 nm and 465 nm. The reddish PL emission with high color purity under different excitation wavelengths from near-UV to blue region may be exploited in solid state lighting-based applications. [ABSTRACT FROM AUTHOR]

We report the photoluminescence (PL) properties of Eu3+ doped HfO2 nanoparticles prepared using co-precipitation method and annealed at 600 °C. X-ray diffraction results revealed the monoclinic phase in undoped HfO2 and show mixed phase formation at lower concentration and a dominant cubic phase achieved at 5 mol% doping of Eu in HfO2. The phase transition anticipated by the density functional theory is in excellent agreement with experimental findings. The oxygen K-edge XANES spectra clearly depicts the diverse hybridization of O 2p orbitals in M–O7 (for monoclinic) and M–O8 (for cubic) polyhedra of HfO2. Hf L-edge XANES confirms Hf4+ ions in cubic and monoclinic structured HfO2. The Eu3+ ions are dominantly present in the Eu-doped HfO2 nanoparticles. PL study demonstrates the emission in red region with high color purity under different excitation wavelengths from near UV to blue light. PL emission spectra show four emission bands at 594 nm, 609 nm, 650 nm, and 716 nm corresponding to 4f–4f transitions of Eu3+ under excitation wavelengths of 361 nm, 383 nm, 394 nm and 465 nm. The reddish PL emission with high color purity under different excitation wavelengths from near-UV to blue region may be exploited in solid state lighting-based applications. [ABSTRACT FROM AUTHOR]

As an efficient molecular engineering approach, on-surface synthesis (OSS) defines a special opportunity to investigate intermolecular coupling at the sub-molecular level and has delivered many appealing polymers. So far, all OSS is based on the lateral covalent bonding of molecular precursors within a single molecular layer; extending OSS from two to three dimensions is yet to be realized. Herein, we address this challenge by cycloaddition between C60 and an aromatic compound. The C60 layer is assembled on the well-defined molecular network, allowing appropriate molecular orbital hybridization. Upon thermal activation, covalent coupling perpendicular to the surface via [4 + 2] cycloaddition between C60 and the phenyl ring of the molecule is realized; the resultant adduct shows frozen orientation and distinct sub-molecular feature at room temperature and further enables lateral covalent bonding via [2 + 2] cycloaddition. This work unlocks an unconventional route for bottom-up precise synthesis of three-dimensional covalently-bonded organic architectures/devices on surfaces. On-surface synthesis (OSS) defines a special opportunity to investigate intermolecular coupling at. sub-molecular level and has delivered many appealing polymers but so-far OSS is limited to the. lateral covalent bonding of molecular precursors. Here, the authors demonstrate cycloaddition. between C60 and an aromatic compound allowing covalent coupling perpendicular to the surface and multiple non-planar covalent coupling of C60. [ABSTRACT FROM AUTHOR]

A novel adsorbent was prepared using a backbone comprising chemically hybridized dialdehyde cellulose (DAC) with chitosan via Schiff base reaction, followed by graft copolymerization of acrylic acid. Fourier transform infrared spectroscopy (FTIR) confirmed the hybridization while scanning electron microscopy (SEM) revealed intensive covering of chitosan onto the surface of DAC. At the same time, energy dispersive X-ray (EDX) proved the emergence of nitrogen derived from chitosan. The X-ray diffraction (XRD) indicated that the crystallinity of the backbone and graft copolymer structures was neither affected post the hybridization nor the grafting polymerization. The adsorbent showed high swelling capacity (872%) and highly efficient removal and selectivity of Ni2+ in the presence of other disturbing ions such as Pb2+ or Cu2+. The kinetic study found that the second-order kinetic model could better describe the adsorption process of (Cu2+, Ni2+) on the graft copolymer. In contrast, the first-order kinetic model prevails for the binary mixture (Pb2+, Ni2+). Moreover, the correlation coefficient values for the adsorption process of these binary elements using Langmuir and Freundlich isotherms confirmed that the developed grafted DAC/chitosan exhibits a good fit with both isotherm models, which indicates its broadened and complicated structure. Furthermore, the grafted DAC/chitosan exhibited high efficient regeneration and high adsorption capacity for Pb2+, Cu2+ and Ni2+. [ABSTRACT FROM AUTHOR]

Correlated 2D layers, like 1T‐phases of TaS2, TaSe2, and NbSe2, exhibit rich tunability through varying interlayer couplings, which promotes the understanding of electron correlation in the 2D limit. However, the coupling mechanism is, so far, poorly understood and is tentatively ascribed to interactions among the dz2${{\mathrm{d}}}_{{{\mathrm{z}}}^2}\ $orbitals of Ta or Nb atoms. Here, it is theoretically shown that the interlayer hybridization and localization strength of interfacial Se pz orbitals, rather than Nb dz2${{\mathrm{d}}}_{{z}^2}\ $orbitals, govern the variation of electron‐correlated properties upon interlayer sliding or twisting in correlated magnetic 1T‐NbSe2 bilayers. Each of the layers is in a star‐of‐David (SOD) charge‐density‐wave phase. Geometric and electronic structures and magnetic properties of 28 different stacking configurations are examined and analyzed using density‐functional‐theory calculations. It is found that the SOD contains a localized region, in which interlayer Se pz hybridization plays a paramount role in varying the energy levels of the two Hubbard bands. These variations lead to three electronic transitions among four insulating states, which demonstrate the effectiveness of interlayer interactions to modulate correlated magnetic properties in a prototypical correlated magnetic insulator. [ABSTRACT FROM AUTHOR]