Ni-O Bonds Research Articles

Structurally Asymmetric Ni-O-Mn Node in Metal-Organic Layers on Carbon Nitride Support for CO2 Photoreduction.

The Jahn-Teller (J-T) effect-induced lattice distortion presents an advantageous approach to tailor the electronic structure and CO2 adsorption properties of catalytic centers, consequently conferring desirable photocatalytic CO2 reduction activity and selectivity. Nevertheless, achieving precise J-T distortion control over catalytic sites to enhance CO2 adsorption/activation and target-product desorption remains a formidable challenge. In this work, we successfully induced J-T lattice distortion in neighboring Ni sites by exchanging high-spin Mn2+ into Ni-O-Ni nodes. EXAFS results and DFT simulations revealed that the highly asymmetric Ni-O-Mn nodes induced structural contraction (shortened Ni-O bonds) in the adjacent Ni-O lattice. The magnetic hysteresis loop (M-H) confirmed that the introduction of Mn2+ increased the number of spin electrons, thereby increasing the magnetization intensity. The spin mismatch between photogenerated electrons and holes suppressed charge recombination. Significantly, the d orbitals of the Ni sites in the Ni-O-Mn nodes exhibited strong orbital hybridization with the p orbitals of CO2, as evidenced by the enhanced d-p orbital overlap, facilitating rapid CO2 adsorption and activation. Consequently, the sample featuring lattice-mismatched Ni-O-Mn nodes exhibited an 8.79-fold enhancement in CO production rate compared to the Ni-O-Ni nodes, in the absence of cocatalysts and sacrificial reagents.

Origin of Enhanced Oxygen Evolution in Restructured Metal-Organic Frameworks for Anion Exchange Membrane Water Electrolysis.

Metal-Organic Frameworks (MOFs), praised for structural flexibility and tunability, are prominent catalyst prototypes for exploring oxygen evolution reaction (OER). Yet, their intricate transformations under OER, especially in industrial high-current environments, pose significant challenges in accurately elucidating their structure-activity correlation. Here, we harnessed an electrooxidation process for controllable MOF reconstruction, discovering that Fe doping expedites Ni(Fe)-MOF structural evolution, accompanied by the elongation of Ni-O bonds, monitored by in-situ Raman and UV-visible spectroscopy. Theoretical modeling further reveals that Fe doping and defect-induced tensile strain in the NiO6 octahedra augments the metal ds-Op hybridization, optimizing their adsorption behavior and augmenting OER activity. The reconstructed Ni(Fe)-MOF, serving as the anode in anion exchange membrane water electrolysis, achieves a noteworthy current density of 3.3 A cm-2 at 2.2 V while maintaining equally stable operation for 160 h spanning from 0.5 A cm-2 to 1 A cm-2. This undertaking elevates our comprehension of OER catalyst reconstruction, furnishing promising avenues for designing highly efficacious catalysts across electrochemical platforms.

Evaluating the mechanism and the capacitive properties of nickel boride electrodes for supercapacitor applications

This study investigates the electrochemical properties of nickel boride electrodes produced via a novel molten salt boron diffusion method; known as cathodic reduction and thermal diffusion-based boriding (CRTD-Bor). Pure nickel substrates with two different geometries (i.e. flat and foam) were borided in the borax-based electrolyte. The presence of nickel borides, composed of NiB, Ni4B3 and Ni2B with the order locations from the surface towards the matrix, was confirmed by X-ray diffractometry (XRD) and scanning electron microscopy (SEM) attached with electron probe microanalyzer (EPMA). The electrochemical behaviors of the produced electrodes were inspected through cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), as well as impedance spectroscopy (EIS). The areal capacitances of the electrodes were calculated as 478 and 1385 mF/cm2 for flat and foam samples, respectively after the 2000th cycle of CV at 10 mV/s scan rate. The reaction kinetic followed the mixed-controlled model according to the Trasatti approach. The capacitive contribution (Co) measured in flat samples was 71 %; whereas, it was found as 40.6 % in the foam-shaped electrodes. Additionally, the mechanism behind the faradaic reactions was explored through X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR) which were conducted both before and after the CV experiments. The obtained results showed that the possible mechanism was related to the formation of NiO bonds due to the oxygen saturation in the defective regions of the surfaces during electrochemical testing. Moreover, the importance of the electrode geometry on the performance was determined by the fact that the porous structure leads to more energy storage and favors a fast charge-discharge trend.

Synthesis and characterization of Ni:ZnO thin films as photoanode for planar perovskite solar cell

Thin films of Ni:ZnO were successfully synthesized by sol-gel spin coating system for 0.5 % and 2.5 % Ni doping concentration on FTO coated substrate. The synthesized films were annealed at 540 °C for 4 h. The annealed thin films were characterized for its electrical, optical and chemical characteristics using UV–Vis, Micro Raman, and FTIR spectroscopy, respectively. The UV–Vis spectra analysis reveals that the energy band gap of deposited films found to be 3.58 eV and 3.51 eV for 0.5 % and 2.5 % Ni:ZnO thin films, respectively. Two significant characteristic peaks identified at 424 cm−1 and 563 cm−1 in Raman spectra. These peaks are attributed to E2high and LO(A1 and E1) modes, which confirms the hexagonal wurtzite phase of Ni:ZnO thin films. Furthermore, the absorption peaks observed at 530 cm−1 and 635 cm−1 in the FTIR spectra are attributed to the characteristic stretching vibrational modes of Zn-O and Ni-O bonds, respectively.

A Cable-Stayed Honeycomb Superstructure to Improve the Stability of Li-Rich Materials via Inhibiting Interlaminar Lattice Strain.

In layered Li-rich materials, over stoichiometric Li forms an ordered occupation of LiTM6 in transition metal (TM)layer, showing a honeycomb superstructure along [001] direction. At the atomic scale, the instability of the superstructure at high voltage is the root cause of problems such as capacity/voltage decay of Li-rich materials. Here a Li-rich material with a high Li/Ni disorder is reported, these interlayer Ni atoms locate above the honeycomb superstructure and share adjacent O coordination with honeycomb TM. These Ni─O bonds act as cable-stayed bridge to the honeycomb plane, and improve the high-voltage stability. The cable-stayed honeycomb superstructure is confirmed by in situ X-ray diffraction to have a unique cell evolution mechanism that it can alleviate interlaminar lattice strain by promoting in-plane expansion along a-axis and inhibiting c-axis stretching. Electrochemical tests also demonstrate significantly improved long cycle performance after 500 cycles (86% for Li-rich/Li half cell and 82% for Li-rich/Si-C full cell) and reduced irreversible oxygen release. This work proves the feasibility of achieving outstanding stability of lithium-rich materials through superstructure regulation and provides new insights for the development of the next-generation high-energy-density cathodes.

Microstructural, antifungal and photocatalytic activity of NiO–ZnO nanocomposite

Abstract In this work, NiO–ZnOnanocomposite (NC)was prepared through a facile, low-temperature,sol–gel route. Zinc acetate dihydrate, nickel chloride hexahydrate, cetyltrimethyl ammonium bromide (CTAB), and citric acid were used in the synthesis of the material. Then, the sample was kept in the muffle furnace at a temperature of 600°C for 2 h. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), UV–Visible spectroscopy, and photocatalytic and antifungal investigations were used to characterize the synthesized nanocrystallites. The XRD data showedthe polycrystalline hexagonal ZnO nanoparticles and cubic NiO crystallites. FTIR studies confirmed the presence of Zn-O and Ni-O bonds in the sample. The FESEM analysis showed the morphology of nanocrystallitescharacterized by their homogeneous shape and size. The absorbance curves from the UV–Visible spectroscopy investigation revealed the bandgap of 3.17 eV. The research findings demonstrate that the NiO–ZnO NC possesses the significant level of selected microbial pathogens. Industrial dyesmake water unhealthy for drinking. Among these dyes, methylene blue (MB) is toxic, carcinogenic, and non-biodegradable, and causes a severe threat to human health and environmental safety. Hence, it is necessary to develop efficient and environmentally friendly technology to remove MB from wastewater. The ZnO–NiO NC degraded the MB dye pollutant under visible irradiation (125 W), according to photocatalytic tests. After 120 min of exposure, the photocatalytic investigations demonstrated 75% degradation efficiency.

Salt-Supported Nickel Oxides for Boosted Hydrogen Production: The Critical Role of Halogen.

Hydrogen production from organic waste by gasification and reforming technologies offers major benefits to both the environment and climate. The long-term stability and regeneration of the reforming catalyst are still the biggest challenges because of carbon deposition. Here we report a recyclable salt-supported nickel oxide NiO/NaX (X: F, Cl, Br) catalyst for effective autothermal reforming of the oxygenated volatile organic compound (OVOC) ethyl acetate to hydrogen. The optimal hydrogen selectivity achieved 82.0% at 650 °C and the durability reached 43 h. Interestingly, with the decreasing of halogen electronegativity (F > Cl > Br) in NaX, the corresponding hydrogen selectivity of the catalysts decreased. Although NiO/NaX catalysts possess a very small specific surface area and a dense microstructure, their catalytic performance is better than that of normal Ni-based catalysts loaded on high-specific-surface-area supports. Detailed investigations revealed the critical roles played by halogen during the reforming reaction. First, the strong electronegative halogen in NaX induced the formation of hydrogen bonds with the reactants and reaction intermediates, which may prolong the surface residence time of such species, thus ensuring efficient hydrogen production over small-specific-surface-area catalysts under high-temperature conditions. Second, the halogen of the support NaX weakening the Ni-O bonds of the exposed Ni atoms in NiO/NaX made it easier for NiO to be reduced to Ni0, thus reducing the reaction activation energy and prompting the rapid catalytic reaction. The strength of such metal-support interaction can be easily modulated by varying the halogen electronegativity. This study provides a new prospect for the design of innovative recyclable heterogeneous catalysts with low specific surface area but high activity.

First-Principles Study of Electronic Structure and Optical Properties of Ni-Doped Bi4O5Br2

In this study, we comprehensively explored the electronic structure and optical properties of Ni-doped Bi4O5Br2 through first-principles computational calculations. By calculating its electronic structure and band characteristics, we investigated the impact of Ni doping on the photocatalytic performance of Bi4O5Br2. The computational results indicated that Ni doping significantly altered the band structure of Bi4O5Br2, leading to a reduction in the band gap width. The band gap for undoped Bi4O5Br2 was 2.151 eV, whereas the Ni-doped system exhibited a smaller band gap, directly indicating its enhanced visible light absorption capacity and facilitating the effective separation of photo-generated electron–hole pairs. Through analysis of 2D charge density maps, we observed changes in chemical bonding induced by Ni doping. The shortening of Ni-O bonds suggested increased bond strength, consistent with the observed reduction in cell volume. These findings provide a theoretical foundation for understanding the mechanisms behind the enhanced photocatalytic hydrogen production performance in Ni-doped Bi4O5Br2, offering valuable insights for the design and optimization of highly efficient photocatalytic materials.

A dinuclear nickel peroxycarbonate complex: CO2 addition promotes H2O2 release.

Nickel coordination compounds featuring Ni-O bonds are key structural motifs in both bioinorganic and synthetic chemistries. They serve as precursors for organic substrate oxidation and are commonly invoked intermediates in water oxidation and oxygen reduction schemes. Herein, we disclose a series of well-defined dinuclear nickel complexes that, upon treatment with CO2 and H2O2, afford the first nickel-bound peroxycarbonate. This unprecedented nickel-oxygen intermediate is stabilized by hydrogen bonding templated across the bimetallic core. Contrasting copper and iron analogues, the nickel peroxycarbonate reversibly dissociates H2O2, a process that is shown to be accelerated by exogenous CO2.

Rapid Charge Transfer Endowed by Interfacial Ni-O Bonding in S-scheme Heterojunction for Efficient Photocatalytic H2 and Imine Production.

Cooperative coupling of H2 evolution with oxidative organic synthesis is promising in avoiding the use of sacrificial agents and producing hydrogen energy with value-added chemicals simultaneously. Nonetheless, the photocatalytic activity is obstructed by sluggish electron-hole separation and limited redox potentials. Herein, Ni-doped Zn0.2 Cd0.8 S quantum dots are chosen after screening by DFT simulation to couple with TiO2 microspheres, forming a step-scheme heterojunction. The Ni-doped configuration tunes the highly active S site for augmented H2 evolution, and the interfacial Ni-O bonds provide fast channels at the atomic level to lower the energy barrier for charge transfer. Also, DFT calculations reveal an enhanced built-in electric field in the heterojunction for superior charge migration and separation. Kinetic analysis by femtosecond transient absorption spectra demonstrates that expedited charge migration with electrons first transfer to Ni2+ and then to S sites. Therefore, the designed catalyst delivers drastically elevated H2 yield (4.55 mmol g-1 h-1 ) and N-benzylidenebenzylamine production rate (3.35 mmol g-1 h-1 ). This work provides atomic-scale insights into the coordinated modulation of active sites and built-in electric fields in step-scheme heterojunction for ameliorative photocatalytic performance.

Enhanced H2O adsorption by Ca2+ doping substantially improves the catalytic performance for light-driven thermocatalytic steam cellulose reforming on Ni/Ca1/8-SiO2

Using renewable biomass to produce syngas can form a closed carbon cycle, curbing carbon emissions. However, thermocatalysis suffers from high energy consumption, while the reaction rates of photocatalysis are relatively low. Here, we report the light-driven thermocatalytic steam cellulose reforming to hydrogen-rich syngas on the Ni nanoparticles loaded on Ca2+ doping SiO2 (Ni/Ca1/8-SiO2). It exhibits a high production rate of hydrogen-rich syngas (H2 3059.4 and CO 1612.1 mmol gcatalyst−1 h−1) and good cycling durability. Tar from cellulose pyrolysis, which is inherently challenging to prevent, is substantially decreased by the involvement of H2O. Ca2+ doping dramatically enhances H2O adsorption, resulting in a significant improvement in catalytic performance. The efficient light-driven thermocatalysis derives from the strong absorption over the whole solar spectrum of Ni/Ca1/8-SiO2 on the one hand. On the other hand, noticeable photoactivation effect is observed to promote the oxidation of carbon species by oxygen due to the surface Ni-O bonds being activated upon light illumination.

Anticancer activity of zinc-nickel nanocomposite in lung cancer PC14 cells via modulation of apoptosis and P13K/mTOR pathway

Advanced innovations for combating variants of aggressive cancer and overcoming drug resistance are desired. In cancer treatment, nanoparticles (NPs) have the capacity to specifically and compellingly activate apoptosis of cancer cells. There is also a pressing need to develop innovative anti-cancer therapeutics, and recent research suggests that ZnO nanoparticles hold great potential.The current exploration was designed to fabricate the zinc-nickel nanomaterial (Zn-Ni NPs) and examine its in vitro anticancer effects on lung cancer cell. In ultraviolet–visible spectroscopy (UV–Vis), the bands at the wavelengths of 219, 265, 397, and 458 nm are related to the surface plasmon resonance of the synthetic Zn-Ni NPs. In fourier transform-infrared spectroscopy (FT-IR), the peaks of 449, 618, 659, 662, and 693 can be assigned to Zn-O or Ni-O bonds. The cytotoxicity of the Zn-Ni NPs (1 to 1000 µg/mL) were studied by the MTT assay and the IC50 dose for Zn-Ni NPs were found at 77 µg/mL. The different fluorescent staining assays such as Dichloro-dihydro-fluorescein diacetate, Rhodamine-123, and dual staining were performed to investigate the influence of Zn-Ni NPs on the apoptosis, matrix metalloproteinase status, and reactive oxygen species accumulation in the PC14 cells. The status of inflammatory markers such as IL-6, COX-2, TNF-α, and NF-κB in the PC14 cells were studied. The increased dosage of Zn-Ni NPs were effective repressed the growth of PC14 cells. The PC14 cells treated with Zn-Ni NPs revealed a significantly fewer proliferating cells and more apoptotic cells when compared with control. The Zn-Ni NPs also inhibited the phosphorylation of mTOR and Akt, reducing tumor volume and weight. PC14 cells phosphorylated mTOR, cyclin D1, Akt, and PI3K in response to Zn-Ni NPs. The findings were revealed that the fabricated Zn-Ni NPs considerably increased the ROS accumulation and apoptosis in the PC14 cells. Zn-Ni NPs also enhanced mitochondrial apoptosis through Bcl-2 protein-dependent signaling. In conclusion, Zn-Ni NPs might be promising candidate for lung cancer treatment.

Synthesis and FTIR Analysis of Cd Doped Nano Ni - Aluminates

Nano Ni – Aluminates (Ni0.5 Fe0.5 Al2O4) and Cd Doped Nano Ni – Aluminates (Ni0.5 Fe0.5 Al2-x CdxO4) where x = 0.2, 0.4, 0.6 and 0.8 were synthesized by co-precipitation method. Ammonium hydroxide was used as precipitating agent. The samples were characterized using Fourier transform infrared spectroscopy. FTIR spectrum for each unannealed sample of Ni0.5 Fe0.5 Al2 O4 and Ni0.5 Fe0.5 Al2-x Cdx O4 exhibit a broad band near 3450 cm-1 due to –OH stretching vibration of free hydrogen bonded hydroxyl group and a second typical absorption band at 1620 cm-1 resulting from deformative vibration of water molecules. Spectra for samples after annealing show peaks in the range of 900-450 cm-1 and 850-500 cm-1 showing presence of Al-O and Ni-O bonds respectively thus confirm the formation of metal oxides bonds while no peak was observed for –OH bond. A peak around 420 cm-1 is assigned to Cd-O bond.

Investigating the enhanced photocatalytic degradation of bromophenol blue using Ni/Zn co-doped Strontium Oxide nanoparticles synthesized via hydrothermal method

Excessive exposure of human to organic contaminants from industrial effluents calls for the implementation of effective pollutants removal techniques. This article investigates the photocatalytic degradation of bromophenol blue dye using Strontium oxide nanoparticles co-doped with Nickel and Zinc. Hydrothermal synthesis produced the nanoparticles, which were subsequently characterized using various analytical techniques. UV/Visible revealed absorption peaks at 294 nm, 306 nm, 311 nm, and 318 nm, while FTIR spectroscopy identified stretching peaks at 416 cm-1, 588 cm-1, and 856 cm-1 for Ni-O and Sr-O bonds. The nanoparticles displayed diameters ranging from 30.50 nm to 36.97 nm. EDX analysis confirmed the elemental composition, with Sr and O comprising of approximately 82.02 %, and Ni and Zn approximately 3.21%. Photocatalytic degradation experiments demonstrated that SrO nanoparticles 85.42% degradation efficiency, while co-doped SrO nanoparticles achieved an impressive 97.97% degradation efficiency. This work highlights the potential co-doped SrO nanoparticles as a promising solution for the efficient removal of organic pollutants from the industrial wastewater, addressing environment contamination concerns.

Self-supported NiO/CuO electrodes to boost urea oxidation in direct urea fuel cells

Direct urea fuel cells (DUFCs) can be used to treat residual wastewater while generating electricity. Herein, self-supported electrodes consisting of NiO nanosheets vertically grown on CuO nanowires are synthesized to realize the urea oxidation reaction (UOR). Such electrodes show excellent UOR performance requiring 1.39 V vs. RHE to achieve 100 mA/cm2. Besides, DUFCs provide open circuit voltages and power densities up to 0.88 V and 11.35 mW/cm2. Electrochemical characterization and Raman spectroscopy prove the formation of NiOOH to enable the UOR. Mott-Schottky analysis and UV photoelectron spectroscopy show the NiO/CuO p-p heterostructure to facilitate the charge transfer from CuO nanowires to NiO nanosheets. Besides, at a local level, density functional theory calculations show that the presence of CuO modulates the electronic states of Ni at the very NiOOH/CuO interface, which results in stretched Ni-O bonds and a uniquely elongated N-H bond of urea that favors its oxidation.

Experimental charge density and topological analysis of tetraaquabis(hydrogenmaleato)nickel(II): a comparison with Hirshfeld atom refinement.

Experimental charge density analysis is conducted on the coordination compound tetraaquabis(hydrogenmaleato)nickel(II), which exhibits a short intramolecular hydrogen bond. Through topological analysis, the nature of Ni-O bonds is concluded to be intermediate between ionic and covalent, but mainly presenting an ionic character, while the short hydrogen bond is classified as covalent in nature. The compound was also analysed after Hirshfeld atom refinement performed using NoSpherA2. A topological analysis was conducted on the molecular wavefunction and the results are compared with those obtained from experiment. In general, there is good agreement between the refinements, and the chemical bonds involving H atoms are in better agreement with what is expected from neutron data after HAR than they are after multipole refinement.

Influence of Ni2+ substitution by Co2+ on the morphology and magnetic properties of single domain CoαNi0.9-αZn0.1Fe2O4 nanoparticles

This study presents the effect of Ni2+ substitution by Co2+ on the structure, morphology and magnetic properties of CoαNi0.9-αZn0.1Fe2O4 nanoparticles calcined at different temperatures. Fourier-transform infrared spectroscopy revealed the presence of Fe-O, Co-O, Zn-O and Ni-O bonds in samples calcined at 200 °C, while the presence of the characteristic bonds of the SiO2 confirmed the embedding of CoαNi0.9-αZn0.1Fe2O4 at all calcination temperatures. Single phase poorly crystalline ferrite for samples calcined at 400 °C and ferrite accompanied by traces of Fe2SiO4 and SiO2 for samples calcined at high temperatures (800 and 1200 °C) were identified. The dependence of X-ray diffraction parameters on the Co2+ content of nanoparticles was also investigated. The increase in Co2+ content and calcination temperature led to crystallite growth from 4 to 43 nm, while the porosity decreased with the increase in Co2+ content and calcination temperature. The magnetic properties of the rectangular shape nanoparticles evolved proportionally with the particle size. The magnetization, coercivity and magnetocrystalline anisotropy increased with the increase in Co2+ content and calcination temperature. The shape of hysteresis loops indicated a superparamagnetic-like behavior of the nanoparticles calcined at 400 °C and a ferrimagnetic-like behavior at higher calcination temperatures (800 and 1200 °C). These features make the obtained nanoparticles attractive candidates for various technical applications.

Facile low-temperature supercritical carbonization method to prepare high-loading nickel single atom catalysts for efficient photodegradation of tetracycline

Environmental photocatalysis is a promising technology for treating antibiotics in wastewater. In this study, a supercritical carbonization method was developed to synthesize a single-atom photocatalyst with a high loading of Ni (above 5 wt.%) anchored on a carbon-nitrogen-silicate substrate for the efficient photodegradation of a ubiquitous environmental contaminant of tetracycline (TC). The photocatalyst was prepared from an easily obtained metal-biopolymer-inorganic supramolecular hydrogel, followed by supercritical drying and carbonization treatment. The low-temperature (300°C) supercritical ethanol treatment prevents the excessive structural degradation of hydrogel and greatly reduces the metal clustering and aggregation, which contributed to the high Ni loading. Atomic characterizations confirmed that Ni was present at isolated sites and stabilized by Ni-N and Ni-O bonds in a Ni-(N/O)6C/SiC configuration. A 5% Ni-C-Si catalyst, which performed the best among the studied catalysts, exhibited a wide visible light response with a narrow bandgap of 1.45 eV that could efficiently and repeatedly catalyze the oxidation of TC with a conversion rate of almost 100% within 40 min. The reactive species trapping experiments and electron spin resonance (ESR) tests demonstrated that the h+, and ·O2− were mainly responsible for TC degradation. The TC degradation mechanism and possible reaction pathways were provided also. Overall, this study proposed a novel strategy to synthesize a high metal loading single-atom photocatalyst that can efficiently remove TC with high concentrations, and this strategy might be extended for synthesis of other carbon-based single-atom catalysts with valuable properties.

Nanostructure, Plastic Deformation, and Influence of Strain Rate Concerning Ni/Al2O3 Interface System Using a Molecular Dynamic Study (LAMMPS)

The plastic deformation mechanisms of Ni/Al2O3 interface systems under tensile loading at high strain rates were investigated by the classical molecular dynamics (MD) method. A Rahman-Stillinger-Lemberg potential was used for modeling the interaction between Ni and Al atoms and between Ni and O atoms at the interface. To explore the dislocation nucleation and propagation mechanisms during interface tensile failure, two kinds of interface structures corresponding to the terminating Ni layer as buckling layer (Type I) and transition layer (Type II) were established. The fracture behaviors show a strong dependence on interface structure. For Type I interface samples, the formation of Lomer-Cottrell locks in metal causes strain hardening; for Type II interface samples, the yield strength is 40% higher than that of Type I due to more stable Ni-O bonds at the interface. At strain rates higher than 1×109 s-1, the formation of L-C locks in metal is suppressed (Type I), and the formation of Shockley dislocations at the interface is delayed (Type II). The present work provides the direct observation of nucleation, motion, and reaction of dislocations associated with the complex interface dislocation structures of Ni/Al2O3 interfaces and can help researchers better understand the deformation mechanisms of this interface at extreme conditions.

Accelerating the reaction kinetics from nitrate to ammonia by anion substitution in NiCo-based catalysts

The electrocatalytic nitrate reduction reaction (NITRR) plays a critical role in maintaining global nitrogen balance, which is strongly depended on the reactive activity of catalysts. Herein, we develop a simple hydrothermal technology to replace the O ions in NiCo2O4 (NCO) by S ions to form NiCo2S4 (NCS), in which the bonding interactions among Ni-O or Co-O bonds are stronger than Ni-S and Co-S bonds. Therefore, more 3d electrons can be localized at Ni or Co sites that can donate more charges to the intermediates. As a result, the ammonia yield can be enhanced to 642 μg h−1 cm−2 and the selectivity can reach 92.42%, which is obviously excellent than NCO. This work provides a new insight into accelerating the electrocatalytic activity by regulating the orbital interaction between anions and cations.