Reactive Metal Research Articles

Accompanying Bi Clusters as Charge Mediators Effectively Enhance Synergetic Redox of Bi2Sn2O7/ZnIn2S4 S-Scheme Heterostructure Composites.

Achieving synergistic oxidation and reduction represents a significant challenge in the field of photocatalysis. In this study, the hydrothermal/in situ construction of Bi atom clusters within Bi2Sn2O7/ZnIn2S4 (BSO/ZIS) heterostructures is reported. These clusters exhibit self-accelerating charge-transfer mechanisms facilitated by internal electric fields and bonding bridges, resulting in highly efficient light absorption and charge-transfer capabilities. In situ X-ray photoelectron spectroscopy (XPS) and Kelvin probe force microscopy (KPFM), as well as theoretical calculations, indicate that the canonical induction and promotion of electrons and holes by the Bi clusters lowers the activation energy of CHO* generation, allowing simultaneous CO2 reduction and toluene oxidation over the catalyst, and enhances proton-coupling and electron-transfer processes, resulting in a unique reaction mechanism. The CO2 and toluene as reactant, the Bi-Bi2Sn2O7/ZnIn2S4 (B-BSO/ZIS) heterostructure achieves a CO2 reduction rate to CO of 726.3µmol g-1h-1 (99.9% selectivity) and a toluene oxidation rate to benzaldehyde of 2362.0µmol g-1h-1 (98.0% selectivity), which increases in activity of 14.6 and 5.7 times compared to pristine ZnIn2S4. This study underscores the significance of modulating the photocatalytic pathway through the strategic selection of metal clusters and reactants, contributing to the rational design of photocatalysts for enhanced CO2 adsorption and stabilization of *H.

Decomposition of Binary Mixtures of DMC/EC, EMC/EC, and DEC/EC on Potassium Surfaces; GC, XPS, and Calculation.

Potassium-ion batteries (KIBs) have emerged as promising candidates for low-cost, high-energy storage systems, driven by their fast ionic conductivity and high operating voltage. To develop advanced KIBs, the performance is usually evaluated in half-cell tests using highly reactive potassium metal, which often leads to misinterpretation of the results due to degradation processes between metal anode and electrolyte components. Here, we systematically investigated the surface reactivity of potassium metal, which is in contact with commonly used solvent combinations, namely, mixtures of ethylene carbonate and linear bis(alkyl)carbonates. Mass spectrometry analysis identified the main electrolyte degradation species, namely, di- and trifunctionalized carbonates, ether-bridged carbonates, and ether-like compounds. Possible reaction pathways for the formation of these products were evaluated by using density functional theory calculations (DFT). X-ray photoelectron spectroscopy showed that potassium metal favors the formation of electrode degradation species, leading to an inorganic rich solid electrolyte interphase composed of K2CO3, KOH, and R-OK species. Additionally, we were able to show how the potassium metal itself forms an initial surface layer containing KOH and K2CO3. This study highlights the complexity of KIB measurements and clearly reveals the challenges of interpreting half-cell tests.

Hydrogen generation through metal waste corrosion: a systematic investigation on old/post-consumer scrap Al6063-series alloy

In this study, aluminum-based wastes are used as energy carriers for on-demand hydrogen production through sustainable, eco-friendly, and cost-effective controlled electrochemical corrosion in aqueous solution. The electrochemical process is very effective because it (i) uses waste metals to produce hydrogen, (ii) corroborates to circular economy, (iii) produces high purity hydrogen, (iv) is based on simple hydrolysis reaction of metals in relevant solutions, (v) electricity is not required and (iv) recovers part of the chemical Gibbs energy of the electrochemical corrosion usually entirely lost in the environment. We systematically studied the generation of hydrogen from industrial waste Dust Scrap Aluminum Alloy (DSAA) belonging to Al 6063 series for the first time. The process is investigated in a novel hand-made batch reactor with a low-cost commercial body suitable to an easy scale-up. Kinetics of DSAA hydrolysis reaction was explored by measuring the variation of aluminium ion concentration at different immersion times through Inductively Coupled Plasma (ICP) and weight loss measurements at different temperatures and NaOH catalyst concentrations. The effect of hydrolysis reaction on the composition and morphology of the metal surfaces in terms of formed oxide layers was studied in detail using Optical Polarizing Microscopy (OPM), Energy dispersive X-ray (EDX) and Scanning Electron Microscopy (SEM) techniques. The criteria used to evaluate the hydrogen reactor performance were hydrogen (i) yield and (ii) production rate. The experimental results showed that a strong increase in NaOH concentration (from 0.75 to 5 M) corresponding to a slow increase in hydrolysis reaction temperature (from 38.8 to 49.9 °C) lead to an improvement in hydrogen generation rate of one order of magnitude, i.e. from 35.71 to 421.41 ml/(g∙min). Low but constant rate of hydrogen can be generated for longer times at low NaOH concentrations (0.75 M), while fast and variable hydrogen generation rate occurs at higher concentrations (5 M) in short times. In the case study of Al 6063 series waste scrap, the hydrolysis reactor parameters can be regulated to deliver hydrogen generation rates from 35.71 to 421.41 ml/(g min) according to requirements. We expect that the results presented in this work will encourage researchers to study the possible use of other metal-based and multi-material plastic/metal wastes thermodynamically prone to electrochemical corrosion process as possible source of hydrogen.Graphical

The Surface Chemistry of Methanol on Cu3Pd(111): Effects of Metal Alloying and Reaction with Hydrogen

The Surface Chemistry of Methanol on Cu₃Pd(111): Effects of Metal Alloying and Reaction with Hydrogen

Charge-to-spin conversion at argon ion milled SrTiO3/NiFe hetero-interfaces

Two-dimensional electron gases (2DEGs) at perovskite oxide interfaces, such as strontium titanate (STO), have garnered significant attention due to their induced ferromagnetic (FM), spin–orbit coupling, and superconducting properties. The 2DEG, formed at the interface between STO and either insulating oxides or reactive metals, exhibits efficient charge-to-spin interconversion in STO/NM(non-magnetic)/FM structures. The insulating oxide layer at the STO interface attenuates the spin currents injected into the ferromagnet. In contrast, the metallic layers facilitate efficient spin current injection but suffer from spin current diffusion. Here, we present an approach to overcome these challenges by directly creating a 2DEG at the STO surface through Ar+ ion bombardment. This method enables efficient spin-to-charge conversion without an intermediate NM layer. Our experimental and simulation results demonstrate the generation of unconventional spin currents at the STO(Ar+)/NiFe (Permalloy) interface. Our findings may enable applications of complex oxide and ferromagnet interfaces for efficient charge-to-spin conversion, paving the way for low-power, room-temperature oxide-based spintronic devices.

Polyvinylidene Fluoride (PVDF)-Trimethylaluminum (TMA) Chemistry: First-Principles Investigation and Experimental Insights.

Atomic layer deposition (ALD) is a popular method of coating battery electrodes with metal oxides for improved cycling stability. While significant research has focused on the interaction between the reactive metal alkyl precursor and the electrode materials, little is known about the reactivity of the precursor toward other components of the battery electrode, such as the polymer binder. This study presents a combined computational and experimental investigation of the reaction between the popular polyvinylidene (PVDF) binder and the trimethylaluminum (TMA) precursor commonly used for coating Al2O3 by ALD. X-ray photoelectron spectroscopy (XPS) was used to interrogate the reactivity of PVDF toward TMA and to characterize the reaction products. Density functional theory (DFT) simulations identified an exothermic reaction of TMA with PVDF, yielding methane (CH4), dimethyl aluminum fluoride, and nonsaturated carbons at the reaction site in the PVDF backbone, which is well aligned with XPS results. The newfound chemistry involving TMA and PVDF reveals that PVDF undergoes side reactions in ALD, contradicting the previous belief that PVDF is chemically inert as a battery binder. This discovery prompts a reassessment of PVDF's application scenarios in the battery industry.

Rationally Reconstructing Attapulgite to MCM-41 and its Superior Application in Formaldehyde Degradation

The inferior reactive metal dispersion caused by lack of structural defects limits the application of MCM-41 in synthesizing effective catalysts. Herein, we substituted conventional silicon source (CTAB) with attapulgite to...

Reactive metal–support interaction of In2O3/crystalline carbon hybrid support for highly durable and efficient oxygen reduction reaction electrocatalyst

Reactive metal–support interaction of In2O3/crystalline carbon hybrid support for highly durable and efficient oxygen reduction reaction electrocatalyst

Prolonged Storage of Bound Organic Carbon in Wetland but Not Upland Soils: A 13C and 14C Perspective

AbstractProtection by metal (hydr) oxides is one of the key mechanisms for the long‐term stabilization of soil organic carbon (SOC). However, the source and turnover of (metal‐) bound organic carbon (OC) in soils are poorly constrained. Here we present the first large‐scale study on the 13C and 14C characteristics of bound OC in 15 wetland and upland soil profiles. We find that bound OC has similar δ13C as SOC, suggesting no preference for plant‐ or microbe‐derived carbon. However, bound OC Δ14C is more negative than SOC in wetland but not upland mineral soils, and decreases with increasing reactive minerals. Hence, in contrast to the conventional assumption, bound OC is better preserved relative to SOC in wetlands with high contents of reactive metals. Our finding highlights the dynamic exchange of bound OC with SOC in upland soils and calls for a better recognition of reactive metals in stabilizing OC in wetlands.

Tallow rosin based binder for extrusion 3D printing feedstock loaded with reactive metal powders

Tallow rosin based binder for extrusion 3D printing feedstock loaded with reactive metal powders

Microelectrodes for Battery Materials.

The ability to measure current and voltage is core to both fundamental study and engineering of electrochemical systems, including batteries for energy storage. Electrochemical measurements have traditionally been conducted on macroscopic electrodes on the order of 1 cm or larger. In this Perspective, we review recent developments in using microscopic electrodes (<100 μm) for the study of battery materials. Microelectrodes allow us to explore spatiotemporal regimes that are not accessible with macroscopic electrodes. Temporally, microelectrodes can generate ultrahigh current densities, enabling the distinction between solid electrolyte interphase (SEI) kinetics and metal deposition kinetics. Spatially, they confine electrochemistry to single particles, allowing us to study their intrinsic properties. We outline future opportunities for the use of microelectrodes for future studies of battery systems. We propose their use for analyzing the electrochemistry of other reactive metals and exploring the potential of combining them with in situ imaging techniques.

Towards High-Performance Li-Rich Cathode Materials: from Morphology Design to Electronic Structure Modulation.

Lithium-rich cathode materials (LRMs) have garnered significant interest owing to their high reversible discharge capacity (exceeding 250 mAh g⁻¹), which is attributed to the redox reactions of transition metal (TM) ions as well as the distinctive redox processes of oxygen anions. However, there are still many problems, such as their relatively poor rate performance and voltage fading and hysteresis, hindering their practical applications. Herein, the recent insights into the mechanisms and the latest advancements in the research of LRMs are discussed. Strategies to promote the performance of LRMs are discussed following a top-down approach from the morphology design to electronic structure modulation. Finally, the ongoing efforts in this area are also discussed to inspire more new ideas for the future development of LRMs.

Corrosion mitigation of mild steel by dimethylol propionic acid: an experimental and theoretical insights with in-vitro cytotoxicity testing on L929 cells

ABSTRACT The corrosion inhibition of mild steel (MS) in 1 M HCl acid utilising Dimethylol propionic acid (DMPA) as an inhibitor has been examined using electrochemical methods (PDP and EIS), both with and without DMPA. The inhibition efficiency at 298 K was determined by increasing the inhibitor concentration (DMPA), which exhibited a maximum effectiveness of 77.93% at 400 ppm for potentiodynamic polarisation (PDP) studies. Atomic force microscopy (AFM) and SEM revealed a protective coating form on the metal surface. The cytotoxicity of the sample was tested in L-929 cells using an MTT cell viability assay revealing that DMPA exhibited no toxicity to mouse fibroblast cells at concentrations up to 40 µg/mL after 24 h of incubation. Density Function theory (DFT) investigations revealed that inhibitors not only transfer electrons from reactive sites to the vacant orbital of the reactive metal but also receive valence electrons from the substrate metal, establishing a protective layer on the metal surface in an acidic solution.

Coordination‐Driven Crosslinking Electrolytes for Fast Lithium‐Ion Conduction and Solid‐State Battery Applications

AbstractRechargeable batteries paired with lithium (Li) metal anodes are considered to be promising high‐energy storage systems. However, the use of highly reactive Li metal and the formation of Li dendrites during battery operation would cause safety concerns, especially with the employment of highly flammable liquid electrolytes. Herein, a general strategy by engineering coordination‐driven crosslinking networks is proposed to achieve high‐performance solid polymer electrolytes. Through the coordination of metal‐organic polyhedra (MOPs) with cellulose‐based copolymers, the Li+‐conducted hypercrosslinked MOP (CHMOP‐Li) polymer network is capable of enabling the rapid transport of Li+. In addition to the high Li+ conductivity (1.02×10−3 S cm−1 at 25 °C), CHMOP‐Li electrolyte also exhibits a high Li+ transference number (0.75) and a wide electrochemical stability window. Benefiting from the thermally stable and mechanically strong CHMOP‐Li electrolyte film, the short‐circuiting of the symmetric batteries is prevented even after 3200 h of cycling and a high specific energy of 300 Wh kg−1 is achieved for the Li‐metal battery. The solid‐state Li−O2 batteries fabricated with CHMOP‐Li electrolyte also show good cycling performance (500 cycles) and high discharge capacity (15740 mAh g−1). The proposed coordination‐driven crosslinking strategies offer an alternative route to design high‐performance next‐generation sustainable battery chemistries.

Coordination-Driven Crosslinking Electrolytes for Fast Lithium-Ion Conduction and Solid-State Battery Applications.

Rechargeable batteries paired with lithium (Li) metal anodes are considered to be promising high-energy storage systems. However, the use of highly reactive Li metal and the formation of Li dendrites during battery operation would cause safety concerns, especially with the employment of highly flammable liquid electrolytes. Herein, a general strategy by engineering coordination-driven crosslinking networks is proposed to achieve high-performance solid polymer electrolytes. Through the coordination of metal-organic polyhedra (MOPs) with cellulose-based copolymers, the Li+-conducted hypercrosslinked MOP (CHMOP-Li) polymer network is capable of enabling the rapid transport of Li+. In addition to the high Li+ conductivity (1.02×10-3 S cm-1 at 25 °C), CHMOP-Li electrolyte also exhibits a high Li+ transference number (0.75) and a wide electrochemical stability window. Benefiting from the thermally stable and mechanically strong CHMOP-Li electrolyte film, the short-circuiting of the symmetric batteries is prevented even after 3200 h of cycling and a high specific energy of 300 Wh kg-1 is achieved for the Li-metal battery. The solid-state Li-O2 batteries fabricated with CHMOP-Li electrolyte also show good cycling performance (500 cycles) and high discharge capacity (15740 mAh g-1). The proposed coordination-driven crosslinking strategies offer an alternative route to design high-performance next-generation sustainable battery chemistries.

Ultrasmall Fe3O4 Nanoparticles on ZrO2 as Catalysts for CO2 Hydrogenation to Lower Olefins

AbstractOrganic synthesis presents significant opportunities for converting the abundant and hazardous carbon dioxide (CO2) in the atmosphere into a more sustainable carbon source. To reduce the carbon footprint, we explored the direct hydrogenation of CO2 to lower (C2‐4=) olefins using various catalysts composed of ZrO2‐supported alkali‐metal‐promoted superparamagnetic iron oxide nanoparticles (SPIONs; Fe3O4). These catalysts are notable for their straightforward preparation; we employed a cost‐effective dry‐mixing method to create a range of alkali metal‐doped SPIONs supported on ZrO2. Results showed that the strong interactions between Fe3O4 and the ZrO2 support enhanced CO2 hydrogenation performance compared to other forms.. Under optimal conditions – using a gas hourly space velocity (GHSV) of 4500 mL/h/gcat. and a feed ratio of H2:CO2=3 : 1 – this catalyst achieved over 22 % CO2 conversion and high selectivity for light (C2–4=) olefins at 30 bar and 375 °C, with 30 wt% Fe3O4 loading on ZrO2 and 2 wt% K promoter. We also investigated several variables, including alkali metal concentration, iron content, reaction conditions, and catalyst stability over 96 hours.

Застосування фторидних вогнетривів для отримання функціо-наль¬них сплавів, що містять хімічно активні компоненти Ti, Zr, Hf, Nb, V

Refractory crucibles, cups and other products made of material based on alkaline earth metals fluorides, which are used for casting, isothermal melting, high-temperature homogenization of chemically aggressive alloys containing a large amount of Ti, Zr, Hf, V, Nb, have been developed and manufactured. However, due to the large difference in coefficients of thermal linear expansion (KTLE) of fluorides and metals, mechanical compression of the crystallizing alloy in the crucible occurs.Such a difference in KTLE leads to cracking and destruction of crucibles. Crucibles that can be disassembled into several parts have been developed. This makes it possible to use such crucibles a large number of times for high-temperature homogenization and melting of chemically active alloys containing Ti, Zr, V, Nb.The developed refractory and special cups made from it also provide new opportunities for scientific research: studying the capillary characteristics (surface tension) of metal melts with a high content of reactive metals, which was previously practically impossible, as well as determining thermodynamic properties (enthalpy of mixing and formation of alloys, activity of components) for these alloys. Keywords: functional metal materials, refractory materials, fluorides of alkaline earth metals, collapsible crucibles, chemically aggressive metals.

Biological and Chemical Processes of Nitrate Reduction and Ferrous Oxidation Mediated by Shewanella oneidensis MR-1.

Iron, Earth's most abundant redox-active metal, undergoes both abiotic and microbial redox reactions that regulate the formation, transformation, and dissolution of iron minerals. The electron transfer between ferrous iron (Fe(II)) and ferric iron (Fe(III)) is critical for mineral dynamics, pollutant remediation, and global biogeochemical cycling. Bacteria play a significant role, especially in anaerobic Fe(II) oxidation, contributing to Fe(III) mineral formation in oxygen-depleted environments. In iron-rich, neutral anaerobic settings, microbial nitrate-reducing Fe(II) oxidation (NRFO) and iron reduction processes happen simultaneously. This study used Shewanella oneidensis MR-1 to create an anaerobic NRFO system between Fe(II) and nitrate, revealing concurrent Fe(II) oxidation and nitrate reduction. Both gene-mediated biological Fe(II) oxidation and chemical Fe(II) oxidation, facilitated by nitrite (a byproduct of nitrate reduction), were observed. The MtrABC gene cluster was linked to this process. At low Fe(II) concentrations, toxicity and mineral precipitation inhibited nitrate reduction by Shewanella oneidensis MR-1, whereas high Fe(II) levels led to Fe(II) oxidation, resulting in cell encrustation, which further constrained nitrate reduction.

Electronic reconfiguration induced by dynamic hydroxyl decoration facilitates electrochemical nitrate reduction to ammonia

Electrochemical conversion from nitrate to ammonia becomes a feasible technology to improve nitrate pollutants and realize room-temperature ammonia synthesis, but which is limited by multiple competing reaction and low energy conversion efficiency. Herein, we suggest dense and well-defined magnetic metal sites on the M(CN)3 (M = Fe, Co, Ni) surface with spontaneous hydroxyl decoration, which leads to electronic rearrangement at half-filled 3d orbitals due to its tailored coordination environment that optimizes nitrate adsorption and dissociation. The comprehensive calculations associated with density functional theory disclose that the rate-limiting potential barrier effectively reduces and finally leads to a higher nitrogen conversion ability, because the bonding interaction and electron transfer between metal sites and reactants is optimized by decorating hydroxyls. This work provides a new insight into understanding the reaction kinetics for nitrate reduction.

Optimizing multi-surface modelling of available cadmium as measured in soil pore water and salt extracts of soils amended with compost and lime: The role of organic matter and reactive metal

The effectiveness of strategies to reduce cadmium (Cd) availability for crop uptake can be assessed using various measures of Cd availability, such as Cd concentration in pore water and Cd extracted with salt solutions. This study evaluated the performance of multi-surface modelling (MSM) to predict dissolved Cd in two Irish tillage soils treated with lime, zinc (Zn) and spent mushroom compost (SMC). Predictions were assessed against Cd measured in three solution media, i.e., 1 mM Ca(NO3)2 and 0.1 M CaCl2 extractions, as well as in soil pore water. Results indicate that reactive soil organic matter (SOM) may be underestimated using a single 0.1 M NaOH extraction in the investigated soils, leading to substantial overestimation of dissolved Cd by MSM, particularly at higher pH. Repeating the 0.1 M NaOH extraction three times substantially improved model predictions. Additionally, using reactive Cd determined by isotopic dilution instead of 0.43 M HNO3 improved model predictions for one of the soils that was rich in manganese (Mn) oxides, revealing a possible role of Mn oxides in determining the reactive Cd fraction. After optimizing reactive SOM and reactive Cd, residuals between predicted and measured Cd showed an increasing trend along with increasing solution pH and decreasing dissolved Cd. This is likely related to Cd binding to high affinity sites due to uncertainties in the binding parameters for these sites and/or to slow desorption kinetics for Cd bound to these sites. Despite significant variations in solution properties, including higher dissolved Ca and reactive dissolved organic matter (DOM), 1 mM Ca(NO3)2 extracts exhibited similar extractable Cd levels, model performance, and Cd speciation compared to soil pore water especially at higher pH. Thus, 1 mM Ca(NO3)2 can be a reliable proxy for soil pore water in assessing Cd availability for crop uptake in soils with circumneutral to alkaline pH.