Metal Molecule Research Articles

Gas-Phase Scattering of Transition Metal Atoms Fe, Ir, and Pt with CH4, O2, and CO2.

Understanding the interactions between transition metal atoms and molecules is important for the study of various related chemical and physical processes. In this study, we have investigated collisions between iron (Fe), iridium (Ir), and platinum (Pt) and the small molecules CH4, O2, and CO2 using a crossed-beam and time-sliced ion velocity map imaging technique. Elastic collisions were observed in all cases, except for collisions of Pt with O2 and CO2. Collisions of Fe or Ir with CH4, O2, and CO2 show mainly long-range attractive potentials at large impact parameters leading to forward scattering, whereas sideways and backward scatterings indicate the formation of short-lived complexes with lifetimes comparable to their rotational periods. In collisions of Pt with O2 and CO2, Pt may react with the gases and become chemically bound to them, which can deplete the nonreactive scattering signal. The insights gained from this study provide a foundation for improved understanding of the complex interactions between transitional metal atoms and other molecules.

CuSx Catalysts for CO2 Electrolyzer Cathode

Because of the climate crisis caused by increasing atmospheric CO2 concentration, developing technologies for reducing them has become imperative. Among various tries, electrochemical CO2 reduction reaction (ECRR) is one of the promising solutions for carbon dioxide recycling as it can be used for the production of more valuable industrial chemicals(e.g. syngas, CO, formic acid...) in a clean way.Ethylene, one of the products, has a high market price of 1.30 dollars/kg. It has various uses for polyethylene production and ethylbenzene synthesis. Ethanol is 1.00 dollars/kg and can be used as fuel. In addition, formic acid has a high value of 0.74 dollars/kg and is used in preservatives and anti-bacterial agents. Carbon monoxide can be easily converted into other hydrocarbon forms through Fischer-Tropsch synthesisFor electrolysis, gas diffusion layer(GDL) based electrolyzers have been used. This is because carbon dioxide has a solubility limit of 33 mM, so humidified carbon dioxide in the form of a gas is used to overcome this up to 41 mM. The hybrid flow cell is an electrolytic bath in which a gas diffusion layer and a cathode liquid layer are separated from the anode by a polymer membrane. It is easy to collect liquid products generated from the cathode side, but it has resistance by the liquid layer. The MEA electrolyzer is an AEMWE-based electrolytic bath in which the cathode liquid layer has been removed. Since the electrode and the membrane are in direct contact and contain a small amount of liquid, a three-phase interface is formed, resulting in an electrolytic reaction.Focusing on the catalyst, Cu is the only mono-metal that shows decent selectivity for multi-carbon products(e.g. ethylene, ethanol, acetate, propanol...). For decades, various researches have been conducted on the development of Cu catalysts through bi-metal composition, oxidation state control and about grain boundaries, crystal facet, single-atom. However, it still has challenges about low partial current density and insufficient stability to commercialize.Herein, copper sulfide catalysts were fabricated on gas diffusible carbon paper with microporous layer(MPL/CP). First, Cu nanoparticles were electrochemically deposited on the MPL/CP. Subsequent immersing it into Na2S solution enables ionic exchange of surface oxygens with S ions. Because the copper sulfide state has low solubility product constant, so is thermodynamically more stable. As reported, sulfur can change the distance between metal molecules, their oxidation state and their morphologies. By adjusting the exchange condition, the catalyst morphology and surface composition can be easily controlled. The fabricated electrodes were employed as cathodes for CO2RR electrolyzer and its faradaic efficiency(FE) was computed. It was revealed that the CO2RR performance was highly affected by S coverage on Cu surface. At some point the existence of Sulfur changed selectivity by enhancing the FE of ethylene and oppressing FE of methane.

(Invited) Bringing Electrochemistry to Raman Spectroscopy Again with Unconventional Approach

Since the landmark discovery of enhanced Raman scattering at electrochemically roughened metal surfaces in 1974 (Chem. Phys. Lett. 1974, 26, 163), electrochemistry has ushered in a new era of Raman spectroscopy. Although the Raman signal is highly specific to molecular species and thus has great potential as a practical tool for molecular identification, its low cross-section has presented a significant challenge. This challenge has been met by the employment of plasmonic nanomaterials, the origins of which can be found in the study reported in 1974. Metallic surface with nanostructure, such as the electrochemically roughened metal surface, has surface plasmon that can greatly amplify both the incident electromagnetic wave and the scattered electromagnetic wave, which is termed electromagnetic (EM) enhancement, resulting in enhanced Raman scattering. This surface-enhanced Raman scattering (SERS) has emerged as one of the most popular analytical tools, thanks to the extensive development of new plasmonic nanomaterials. In addition to this material-wise signal enhancement, an electrochemical method can enhance Raman scattering by inducing a resonance condition: a charge-transfer resonance by the electron transfer between metal and Raman-active molecule. For achieving this chemical (CM) enhancement, it is essential to ensure proper alignment of the Fermi level of metal, the energy level of molecular orbitals, and the energy of incident light, and the application of electrochemical potential to the metal can adjust the Fermi level to meet the resonance condition.Here, we present a unique application of electrochemical processes that can induce both EM and CM enhancements. In the presence of a metal cation (i.e., a precursor of a plasmonic substance), a suitable electrode potential can generate a new plasmonic surface on the electrode. This process can enhance the Raman signal of the molecule adsorbed on the electrode prior to the potential application, via the EM enhancement mechanism. Since the newly formed plasmonic surface is retained even after the potential application is terminated, the continuation of EM enhancement is expected; however, the Raman signal is significantly reduced. In addition, the Raman enhancement observed during the potential application is mode-selective, which is one of the characteristics of CM enhancement. In combination, the electrochemical process involving a plasmonic metal precursor harnesses both EM and CM enhancements, yielding a great enhancement of the Raman signal. The mechanistic study of this platform and its applications will be presented in this talk.

Magnetic proximity effect and spin transport properties of MnPc/CuPc/MnPc molecular spintronic device

Molecular-scale spintronic devices show great application potential in information storage due to tiny size and rich controllability. Spin transport of molecular devices relies heavily on the magnetic interaction between magnetic metal atom and molecule, which is the core of determining the performance of spintronic devices. In this study, the magnetic proximity effect in MnPc/CuPc/MnPc molecular device and the influence on spin transport were investigated using non-equilibrium Green’s function method in combination with density functional theory. Mn atoms in MnPc molecules not only endow magnetism with system, but also trigger magnetic proximity effect which works in synergy with the spin filtering of phthalocyanine molecules to achieve a spin injection efficiency of 100 % in molecular device, and this efficiency remains stable under bias voltage. The MnPc/CuPc/MnPc molecular device shows a tunneling magnetoresistance ratio of up to 4165 % at 5 mV, indicating potential application in multifunctional spintronic devices. This work elucidates the unique physical properties and excellent performance of MnPc/CuPc/MnPc molecular device, providing valuable insights for spintronic applications.

Assessment of the similarity-transformed equation of motion (STEOM) for open-shell organic and transition metal molecules.

This study benchmarks the newly re-implemented single-reference excited-state methods, IP-EOM-CCSD, EA-EOM-CCSD, and STEOM-CCSD, in ORCA6.0, with a focus on open-shell systems. We compare STEOM against EOM-CCSD, CC3, and CCSDT across a range of systems, including small organic radicals, hydrated transition metal (TM) ions, and TM diatomic systems with both closed and open-shell configurations. For organic radicals, STEOM and EOM-CCSD show comparable performance, aligning closely with CC3 and CCSDT results. In the case of hydrated TM ions, IP-EOM closely matches DLPNO-CCSD results, while deviations from DLPNO-CCSD(T) are consistent. For open-shell TM systems, IP-EOM exhibits a blueshift relative to both the DLPNO-CCSD methods, while EA-EOM-CCSD shows better agreement. When comparing STEOM and CC3 to CCSDT, STEOM shows slightly larger deviations in closed-shell systems but shows excellent agreement in open-shell systems. Computational efficiency is also assessed, revealing a significant speedup in ORCA 6.0 compared to ORCA 5.0, with optimizations improving computation times. This study provides valuable insights into the performance and efficiency of STEOM in various chemical environments, highlighting its strengths and limitations.

Weak interaction induced selective separation of V/Mo/Co from spent hydrodesulfurization catalyst leaching solution: Mechanism and strategy

Spent hydrodesulfurization catalysts contain more than 10 ∼ 25 wt% V, Mo and Co, which are not only hazardous materials, but also can be considered as valuable secondary resources. The complete separation of these complex critical metals by solvent extraction still needs to be improved. Here, a selective extraction route for the separation of V/Mo/Co is proposed based on the weak interaction differences between extractants and metal, which is realized by theoretical calculation and experimental verification. This process does not require pretreatment of N1923 and Cyanex272 (C272), thus reduced the consume of acid and base as well as generation of waste water. With the preliminary results of V/Mo, Co/Mo, and V/Co separation, the weak interaction between extractants and metal molecules was revealed by quantum chemical calculations quantitatively. The molecular charge distribution, surface electrostatic potential distribution (ESP) and the average local ionization energy (ALIE) shows the priority reactivity of the metal molecules as: H6V10O28 > H2Mo4O13 > H4V4O12 > H3VO4 > H2MoO4. The independent gradient model based on Hirshfeld partition (IGMH) show differences in the weak interaction forces as: N1923-V>C272-Mo > C272-V>N1923-Mo > C272-Co. The selective separation process of V/Mo/Co was designed with the guide of above results. The combined recovery of the three metals V, Mo and Co amounted to 83.88 %, 87.08 %, and 99.01 %, respectively. The whole route reduces 3.92 t sulfuric acid and 7.83 t sodium hydroxide per solid, and reduces 1.99 t carbon emissions compared to the conventional route.

Efficacy of zinc as an adjuvant therapy in acute pneumonia in children of age 2 months to 2 years: A randomized controlled trial

Background: Pneumonia is the most common Illness affecting infants and children globally. Childhood pneumonia has been identified as the major “forgotten killer of children” by UNICEF and the WHO. The WHO and United Nations Children’s Fund (UNICEF) in 2013, published the integrated Global Action Plan for Pneumonia and Diarrhoea (GAPPD) which outlined a framework for ending preventable child deaths due to diarrhoea and pneumonia by 2025. Zinc is a vital micro element that is essential for a variety of fundamental biological processes due to its function as a transition metal, cofactor, structural component, and signalling molecule. Zinc is also an essential component of antibacterial immunity. The impaired immunocompetence due to low zinc states enhances the establishment of a particular infection due to a reduction in the clearance of infectious agents. Recommend zinc nutritional intake is 10-20mg/day for children. It is estimated that 17-20% of the world’s population may be zinc deficient. Zinc deficiency is common among children in developing countries because of inadequate food intake, particularly from animal source and limited bioavailability from local diet. It has been proposed that zinc can be a real potential in the prevention of pneumonia morbidity and mortality. Objective: To study the effect of zinc supplementation as an adjuvant therapy on outcome of pneumonia. Method: We conducted a randomised controlled trial from march 2023 to february 2024. All children in the the age group of 2 months to 2 years, who presented with the features of pneumonia to the department of Paediatrics in Akash institute of medical sciences and research centre Devanhalli, Bangalore rural. Ethics consent was obtained from Institutional ethical committee. Demographic details such as name, age, gender along with clinical profile was taken. After admission, detailed history and physical and systemic examination were carried out and necessary data collected. Sample size being 50 cases, they were divided in two groups as case group (zinc group) and control group by stratified randomisation, 25 participants being in each group. Enrolled children were given standard treatment for pneumonia in the form of oxygen, intravenous fluids, bronchodilators, parenteral antibiotics. Enteral feeds were started once the child respiratory distress improved, oxygen saturations greater than 93%, baby was able to tolerate feed. Zinc group received 20 mg of elemental zinc per day as a single dose for 7 days. Result : Out of the total 50 cases, two groups were divided with 25 cases in zinc group and 25 cases in non-zinc group. In zinc group 6 cases (50%) took 24-48 hours for disappearance of symptoms, another 3 cases (26%) less than 24 hours, in 1 case time for disappearance of symptoms was 48-72 hours, another case which took 72-96 hours. The mean duration of time taken for disappearance of danger signs was 42.33 ± 13.89 hours. In the non-zinc group (36%) 5 cases took 24-48 hours for disappearance of danger signs, 3 cases (22%) which took 48-72 hours and 2 cases (14%) which took 96-120 hours, 2 more cases (14%) which took 120-144 hours. The mean duration of hospital stay in non-zinc group was 62.28 ± 10.84 hours which is comparatively more than that of zinc group. Conclusion: This study concluded that zinc supplementation shortens the time taken for resolution of respiratory distress and resolution of symptoms. However, it was not found to be of much help in improving oxygen saturation. It also did not show any significant decrease in time taken for disappearance of danger signs and duration of hospital stay.

Synthesis and Characterization of Coordination Compounds with Novel Ligands: Implications for Material Science

Coordination compound are any of a class of substances with produced plans where a central metallic particle is encircled by non-metal elements or social assemblies of particles, termed ligands. A basic use of coordination compounds is their use as motivations, which effectively change the speed of designed responses. This study researches the mix and depiction of coordination compounds incorporating novel ligands, with an accentuation on their ideas for material science. Coordination compounds, outlined by the coordination of a central metal atom or molecule with various ligands, are crucial for an extent of engineered and present day cycles. In this investigation, we detail the mix of a couple of coordination compounds featuring as of late made ligands. These ligands are planned to give express electronic and steric influences, smoothing out the introduction of the ensuing edifices.

Molecular Triplet Generation Enabled by Adjacent Metal Nanoparticles.

High-efficiency generation of spin-triplet states in organic molecules is of great interest in diverse areas such as photocatalysis, photodynamic therapy, and upconversion photonics. Recent studies have introduced colloidal semiconductor nanocrystals as a new class of photosensitizers that can efficiently transfer their photoexcitation energy to molecular triplets. Here, we demonstrate that metallic Ag nanoparticles can also assist in the generation of molecular triplets in polycyclic aromatic hydrocarbons (PAHs), but not through a conventional sensitization mechanism. Instead, the triplet formation is mediated by charge-separated states resulting from hole transfer from photoexcited PAHs (anthracene and pyrene) to Ag nanoparticles, which is established through the rapid formation and subsequent decay of molecular anions revealed in our transient absorption measurements. The dominance of hole transfer over electron transfer, while both are energetically allowed, could be attributed to a Marcus inverted region of charge transfer. Owing to the rapid charge separation and the rapid spin-flip in metals, the triplet formation yields are remarkably high, as confirmed by their engagement in production of singlet oxygen with a quantum efficiency reaching 58.5%. This study not only uncovers the fundamental interaction mechanisms between metallic nanoparticles and organic molecules in both charge and spin degrees of freedom but also greatly expands the scope of triplet "sensitization" using inorganic nanomaterials for a variety of emerging applications.

Simple distance-based thread analytical device integrated with ion imprinted polymer for Zn2+ quantification in human urine samples.

This article presents the development of a distance-based thread analytical device (dTAD) integrated with an ion-imprinted polymer (IIP) for quantitative monitoring of zinc ions (Zn2+) in human urine samples. The IIP was easily chemically modified onto the thread channel using dithizone (DTZ) as a ligand to bind to Zn2+ with methacrylic acid (MAA) as a functional monomer and ethylene glycol dimethacrylate (EGDMA) as well as 2,2-azobisisobutyronitrile (AIBN) as cross-linking agents to enhance the selectivity for Zn2+ detection. The imprinted polymer was characterized using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy and Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS). Under optimization, the linear detection range was from 1.0 to 20.0 mg L-1 (R2 = 0.9992) with a limit of detection (LOD) of 1.0 mg L-1. Other potentially interfering metal ions and molecules did not interfere with this approach, leading to high selectivity. Furthermore, our technique exhibits a remarkable recovery ranging from 100.48% to 103.16%, with the highest relative standard deviation (% RSD) of 5.44% for monitoring Zn2+ in human control urine samples, indicating high accuracy and precision. Similarly, there is no significant statistical difference between the results obtained using our method and standards on zinc supplement sample labels. The proposed method offers several advantages in detecting trace Zn2+ for point-of-care (POC) medical diagnostics and environmental sample analysis, such as ease of use, instrument-free readout, and cost efficiency. Overall, our developed dTAD-based IIP method holds potential for simple, affordable, and rapid detection of Zn2+ levels and can be applied to other metal ions' analysis.

Machine-learning-enabled exploitation of gas-sensing descriptors: A case study of five pristine metal oxides

Machine learning, a new research paradigm, is promising for device design, material discovery, and theoretical exploration, overcoming the drawbacks of experimental approaches. In this study, we used machine learning to explore the gas-sensing reactions of metal oxides. The training data were experimental results. Three types of features — metal oxide and gas molecule properties and operating conditions — were extracted as inputs for the machine learning algorithms. The genetic algorithm-adjusted artificial neural network achieved the best performance, and the neural network test was performed using two new experimental datasets. Further, Shapley Additive exPlanations were employed to understand the findings and explore key descriptors for gas sensing. The feature importance was ranked, and the first six features were selected as key descriptors for gas sensing using metal oxides. Furthermore, theoretical investigations were conducted, and the correlations between features and outcomes were analyzed. We found that the active site for gas sensing on pristine metal oxides comprises ionic oxygen loosely bonded to the metal sites. This study provides an example of the use of machine learning for material discovery. We expect that this study will encourage more studies on machine learning for gas sensing.

Tuning and Modulation of the Photoinduced Current by Rectification of Surface Plasmons in Metal–Molecule–Nanoparticle–ITO Composite Junctions

Tuning and Modulation of the Photoinduced Current by Rectification of Surface Plasmons in Metal–Molecule–Nanoparticle–ITO Composite Junctions

Photoinduced [3 + 2] Cycloadditions of Aryl Cyclopropyl Ketones with Alkynes and Alkenes.

The five-membered ring skeleton is one of the most pivotal in the area of pharmaceutical and natural products. [3 + 2] cycloadditions of cyclopropyl and unsaturated compounds are a highly efficient and atom-economical way to build a five-member compound. The previous works about the kind of [3 + 2] cycloadditions usually utilized metal or organic small molecule catalysts. However, an ideal [3 + 2] cycloaddition reaction that smoothly happens without any additives and catalysts under mild conditions is underdeveloped. Hence, we report [3 + 2] cycloadditions of aryl cyclopropyl without any additives and catalysts under purple LED. In this method, a broad scope of cyclopropyl, alkyne, and alkene was very compatible, especially drug derivatives ibuprofen and Ioxoprofen, to obtain the corresponding cycloaddition product with a good yield up to 93%.

Contrast-enhanced Susceptibility Weighted Imaging (CE-SWI) for the Characterization of Musculoskeletal Oncologic Pathology: A Pictorial Essay on the Initial Five-year Experience at a Cancer Institution

Susceptibility-weighted imaging (SWI) is based on a 3D high-spatial-resolution, velocity-corrected gradient-echo MRI sequence that uses magnitude and filtered-phase information to create images. It SWI uses tissue magnetic susceptibility differences to generate signal contrast that may arise from paramagnetic (hemosiderin), diamagnetic (minerals and calcifications) and ferromagnetic (metal) molecules. Distinguishing between calcification and blood products is possible through the filtered phase images, helping to visualize osteoblastic and osteolytic bone metastases or demonstrating calcifications and osteoid production in liposarcoma and osteosarcoma. When acquired in combination with the injection of an exogenous contrast agent, contrast-enhanced SWI (CE-SWI) can simultaneously detect the T2* susceptibility effect, T2 signal difference, contrast-induced T1 shortening, and out-of-phase fat and water chemical shift effect. Bone and soft tissue lesion SWI features have been described, including giant cell tumors in bone and synovial sarcomas in soft tissues. We expand on the appearance of benign soft-tissue lesions such as hemangioma, neurofibroma, pigmented villonodular synovitis, abscess, and hematoma. Most myxoid sarcomas demonstrate absent or just low-grade intra-tumoral hemorrhage at the baseline. CE-SWI shows superior differentiation between mature fibrotic T2* dark components and active enhancing T1 shortening components in desmoid fibromatosis. SWI has gained popularity in oncologic MSK imaging because of its sensitivity for displaying hemorrhage in soft tissue lesions, thereby helping to differentiate benign versus malignant soft tissue tumors. The ability to show the viable, enhancing portions of a soft tissue sarcoma separately from hemorrhagic/necrotic components also suggests its utility as a biomarker of tumor treatment response. It is essential to understand and appreciate the differences between spontaneous hemorrhage patterns in high-grade sarcomas and those occurring in the therapy-induced necrosis process in responding tumors. Ring-like hemosiderin SWI pattern is observed in successfully treated sarcomas. CE-SWI also demonstrates early promising results in separating the T2* blooming of healthy iron-loaded bone marrow from the T1-shortened enhancement in bone marrow that is displaced by the tumor. SWI and CE-SWI in MSK oncology learning objectives: SWI and CE-SWI can be used to identify calcifications on MRI. Certain SWI and CE-SWI patterns can correlate with tumor histologic type. CE-SWI can discriminate mature from immature components of desmoid tumors. CE-SWI patterns can help to assess treatment response in soft tissue sarcomas. Understanding CE-SWI patterns in post-surgical changes can also be useful in discriminating between residual and recurrent tumors with overlapping imaging features.

“Ship-in-a-bottle” entrapment of biomolecules in MOF-based xerogel monoliths for high-performance electrochemical hydrogen evolution

The “ship-in-a-bottle” entrapment of bioactive molecules in metal–organic framework (MOF)-based xerogel monoliths based on a controlled mesopore architecture was reported.

Influence of molecular structure on the coupling strength to a plasmonic nanoparticle and hot carrier generation.

Strong coupling between metal nanoparticles and molecules mixes their excitations, creating new eigenstates with modified properties such as altered chemical reactivity, different relaxation pathways or modified phase transitions. Here, we explore excited state plasmon-molecule coupling and discuss how strong coupling together with a changed orientation and number of an asymmetric molecule affects the generation of hot carriers in the system. We used a promising plasmonic material, magnesium, for the nanoparticle and coupled it with CPDT molecules, which are used in organic optoelectronic materials for organic electronic applications due to their facile modification, electron-rich structure, low band gap, high electrical conductivity and good charge transport properties. By employing computational quantum electronic tools we demonstrate the existence of a strong coupling mediated charge transfer plasmon whose direction, magnitude, and spectral position can be tuned. We find that the orientation of CPDT changes the nanoparticle-molecule gap for which maximum charge separation occurs, while larger gaps result in trapping hot carriers within the moieties due to weaker interactions. This research highlights the potential for tuning hot carrier generation in strongly coupled plasmon-molecule systems for enhanced energy generation or excited state chemistry.

Hydrogen storage metal-organic frameworks: From design to synthesis

For many years, there has been great interest in metal-organic frameworks, or MOFs. MOFs are a family of crystalline hybrid organic-inorganic compounds made up of strong coordination interactions connecting metal molecules to organic ligands. Due to their vast specific surface area, structural diversity, and adjustable pore size and functionality, they are highly advantageous in a variety of applications, including hydrogen storage. As a result, MOFs have been thoroughly researched. This study examines the drawbacks of traditional hydrogen storage methods before concentrating on MOFs’ potential as a cutting-edge material to get around these issues. The work also illustrates the benefits of MOFs in enhancing hydrogen adsorption performance by examining the synthesis techniques, functionalization tuning strategies, and their use with metal nanoparticle composites. Simultaneously, the significance of fine-tuning the functionalization and optimizing the performance of MOFs is underscored, and their potential to foster hydrogen-based economic growth is anticipated.

Key Factors for Controlling Plasmon-Induced Chemical Reactions on Metal Surfaces.

Plasmon-induced chemical reactions based on direct interactions between the plasmons of metal nanostructures and molecules have attracted increasing attention as a means of efficiently utilizing sunlight. In recent years, achievements in complex synthetic reactions as well as simple dissociation reactions of gaseous molecules using plasmons have been reported. However, recent research progress has revealed that multiple factors govern plasmon-induced chemical reactions. This perspective provides an overview of the key factors that influence plasmon-induced chemical reactions on metal surfaces and discusses the difficulty of controlling the reactions, which is caused by the entanglement of the key factors. A strategy for designing plasmonic metal catalysts to achieve the desired reactions is also discussed based on the current understanding, and directions for further research are provided.

Isotherm Study, Adsorption Kinetics and Thermodynamics of Lead Using Combination Adsorbent of Chitosan and Coffee Ground Activated Carbon

The presence of lead metal in water naturally due to its mobility can cause the nature of water to become toxic and endanger the environmental ecosystem because it bioaccumulates in the food chain. The purpose of this study was to study the maximum adsorption capacity through an isotherm model, to determine the rate of adsorption kinetics in the use of chitosan and coffee grounds adsorbents in reducing lead concentrations in industrial wastewater and to study its thermodynamic magnitude. The research method was carried out using experiments in the laboratory followed by quantitative data analysis to determine the isotherm model and adsorption kinetics. The results showed that the adsorption isotherm follows the Langmuir isotherm model with a correlation coefficient of 0.9970 with a maximum adsorption capacity of 1.0511 mg.g-1 which indicates that chemical adsorption occurs in the mono layer with a homogeneous distribution of adsorption sites with adsorption energy. constant and negligible interactions between lead metal molecules (adsorbate). Study of lead adsorption kinetics using chitosan-activated carbon coffee grounds following the Weber-Morris/intra-particle diffusion model with a correlation coefficient of 0.9920 with a diffusion rate of 76.512 g.mg-1.hour-1 indicating that intra-particle diffusion is the rate step limiting in the overall biosorption process. Negative ΔGo values ​​indicate that the adsorption reaction takes place spontaneously, ΔHo of 0.8130 indicates an endothermic reaction, and ΔSo of 4.1888 indicates an increase in the randomness of the adsorption process at the adsorbent interface and lead during adsorption.

Comprehensive protection of Zn metal anode via caprolactam towards highly stable aqueous zinc ions batteries

Rampant side reactions such as hydrogen evolution reaction (HER), corrosion and uncontrollable dendrite growth at anodes greatly impede the application of AZIBs. Herein, caprolactam (CPL) is employed as a crucial electrolyte medium to achieve the aim of highly reversible zinc anodes. CPL molecules exhibit a lower adsorption energy (−1.94 eV) than H2O and preferential binding with Zn anodes, resulting in a H2O-poor anode/electrolyte interface and an enhanced steric effect at the anode surface. This effect effectively hinders the contact between zinc metal and water molecules, consequently facilitating the uniform and controlled deposition of Zn2+. Furthermore, the combination between CPL and Zn2+ contributes to the optimization of solvation structures. Consequently, Zn/Zn batteries with CPL additives realized more than 2100 h stable cycling life under 1 mA cm−2 and 1 mAh cm−2. Moreover, Zn/Cu batteries with CPL additives achieved a reversible plating/stripping process for over 3000 cycles with high average CE of 99.4%. Besides, the assembled Zn/NH4V4O10 full batteries using electrolyte of ZnSO4/CPL also exhibited excellent cyclic performance. The batteries yielded 77.1 mAh g−1 under the current density of 5 A g−1 after 1000 cycles. CPL demonstrates significant potential as a cost-effective and multifunctional electrolyte additive for achieving stable and reliable AZIBs.