Octahedral Structure Research Articles

Tridentate N-donor Schiff base metal Complexes: Synthesis, Characterization, computational Studies, and assessment of biomedical applications in cancer Therapy, Helicobacter pylori Eradication, and COVID-19 treatment

A unique Schiff base ligand (BCA), 4-(2-((1E,2E)-1-(2-(p-tolyl)hydrazono)propan-2-ylidene)hydrazinyl)quinazoline, was synthesized and complexed with Mn [II], Co [II], Cu [II, and Cd [II] ions, with 1,10-Phenanthroline (PHN) as an auxiliary ligand. The unique Schiff base ligand BCA and its metal complexes were characterized using multiple analytical techniques, including elemental analysis, UV–visible spectroscopy, FT-IR, mass spectrometry, and conductometric measurements. These methods provided detailed insights into the compounds’ structural and electronic properties. Density Functional Theory (DFT) computations complemented the experimental data, elucidating electronic configuration stability, HOMO-LUMO energy gaps, chemical hardness, and dipole moments. The computational results confirmed the distorted octahedral structure of the complexes. Antimicrobial testing against various bacterial and fungal strains revealed that the Cd (II) complex exhibited the highest activity, with inhibition zones ranging from 19.7 ± 0.6 mm to 35.0 ± 1.0 mm, surpassing the activity of standard antibiotics in some cases. Notably, the compounds displayed significant efficacy against Helicobacter pylori, with the Cd (II) complex showing an inhibition zone of 32.67 ± 0.58 mm and a minimum inhibitory concentration (MIC) of 7.8 μg/ml. Anticancer properties were evaluated against MCF-7 (Breast carcinoma) cells, with the [(BCA)(PHN)Cd(H2O)].2Cl·2H2O complex demonstrating superior activity (IC50 = 29.97 μg/ml) compared to the free ligand (IC50 = 183.96 μg/ml) and other metal complexes. Notably, the Cd(II) complex showed reduced cytotoxicity towards normal VERO cells, suggesting potential selectivity for cancer cells. Molecular docking simulations evaluated the complexes’ binding interactions with protein targets associated with Helicobacter pylori, MCF cancer cells, and the COVID-19 virus. The main objective of this research was to design and synthesize a unique Schiff base ligand and its new corresponding Ternary metal complexes and then investigate their potential medical applications. Specifically, the study aimed to evaluate the compounds’ effectiveness as antibiotics, antitumor agents, and possible treatments for COVID-19.

Synthesis, Characterization, DFT Calculations, and Pharmacological Activity of Azo Dye Ligand and Its Cu(II) Complex Comprising Nitrogen and Oxygen Donor Atoms

ABSTRACTCoupling the diazonium salt of sulfadiazine with dibenzoylmethane afforded the 4‐(2‐(1,3‐dioxo‐1,3‐diphenylpropan‐2‐ylidene)hydrazinyl)‐N‐(pyrimidin‐2‐yl)benzene sulfonamide ligand (HL). The ligand (HL) and its Cu(II) complex structure have been investigated via magnetic attraction testing, TGA, FTIR, UV–visible, XRD, and CHN analyses. The spectrum data indicate that the ligand demonstrates monobasic bidentate behavior via deprotonating opposite the oxygen atom of the carbonyl (CO) group and linking using the NH of the hydrazone group (NNH). Copper (II) complex present in octahedral structure. A number of TGA steps (Ea, A, ΔH*, ΔS*, and ΔG*) had their dynamical characteristics computed and described using the Coats–Redfern and Horowitz–Metzger formulas. Molecular studio programmer was utilized to perform density functional theory (DFT) calculations in order to investigate the ideal configuration of HL and its Cu(II) complex. The HL and its copper (II) complex exhibited antitumor effects against MCF‐7 and HepG‐2 cell lines. Furthermore, the width of the inhibition zone was employed to evaluate the in vitro antibacterial effect of HL and a specific complex towards Gram‐negative organisms Escherichia coli (E. coli) and Gram‐positive organisms Staphylococcus aureus. The ligand and its Cu(II) complex were examined using both the viscosity and spectrum of absorption of calf thymus DNA binding experiments.

Zr-Doped High-Voltage Spinel LiNi0.5Mn1.5O4 Manufactured via the Coprecipitation Method.

Lithium nickel manganese oxide (LiNi0.5Mn1.5O4, LNMO) provides an elevated operating potential of 4.7 V and a theoretical capacity of 147 mAh g-1, without the need for expensive cobalt. Zr-doped LNMO was synthesized using the coprecipitation technique with Couette-Taylor flow. FE-SEM images and TEM SAED patterns revealed that Zr-doped LNMO formed truncated octahedral structures with exposed (100) crystal facets. When compared to undoped LNMO, Zr-doped LNMO exhibited superior electrochemical performance. Electrochemical evaluations showed that Zr0.1-LNMO achieved 85.9% rate capability at 10 C, significantly outperforming the 69.1% of bare LNMO. In addition, Zr0.1-LNMO exhibited high stability, maintaining 76.8% of the discharge capacity even after 100 cycles.

High-entropy strategy to suppress volumetric strain and enhance diffusion rate of Na3V2(PO4)2F3 cathode for durable and high-areal-capacity zinc-ion battery pouch cells

Aqueous zinc-ion batteries are pivotal contributors to the global energy transformation. Cathode materials with NASICON-type structures are promising candidates for zinc-ion batteries but are hindered by their low electrical conductivity, sluggish ionic diffusion, and structural instability. This work introduces a high-entropy, carbon-coated NASICON-type Na3V2(PO4)2F3 (HE-NVPF@C) cathode by incorporating five metal elements (Al, Zn, Mn, Cr, and Nb) mainly into the V sites of the VO4F2 octahedral structure. Systematic experimental and simulation studies of the Zn2+ storage mechanism in high-entropy NASICON-type cathode are presented for the first time. The high-entropy doping strategy contributes to significantly enhanced cycling stability by suppressing Jahn-Teller distortion, reducing lattice change during Zn2+ extraction and insertion, and decreasing the Zn2+ migration energy barrier. As a result, the HE-NVPF@C cathode demonstrates exceptional cycling stability over 6000 cycles at 20 C with a capacity loss of a mere 0.0031 % per cycle and a high areal capacity retention of 2.17 mAh cm−2. In addition, the pouch cell provides a long cycling lifespan with 90.8 % capacity retention at 5 C after 200 cycles. This feasible high-entropy approach broadens the perspective for developing practical zinc-ion batteries with a long cycle lifespan and high areal capacity.

Lyophilization strategy to synthesize ultrafine NaCl template for preparation of photocatalytic BiOCl nanoplates via chemical vapor deposition

Two-dimensional (2D) bismuth oxychloride (BiOCl) has attracted increasing attention in nanoelectronics, catalysis, energy storage, and the environment, attributed to its wide indirect band gap and large surface area. However, the imprecise control of the catalytic site on the substrate makes it challenging to produce 2D BiOCl in large quantities economically. Here, we developed lyophilization to create ultrafine NaCl templates to obtain a higher yield of 2D BiOCl nanoplates than traditional substrates using a chemical vapor deposition (CVD) method. In contrast to ball milling or recrystallization, lyophilization can produce the sodium chloride (NaCl) in the ice lattice domain, resulting in ultrafine NaCl particles after removing water. Moreover, the NaCl particles synthesized by lyophilization showed lower crystallinity with partially distorted structures, such as twisted octahedral structures and the structure with Na+ separated from other atoms by an ice lattice. In addition, our method offers an opportunity to introduce and engineer the oxygen vacancies (OVs) on 2D BiOCl to narrow the band gap, improve the separation of photogenerated carriers, and enhance their photocatalytic efficiency by 17.2 times. Thus, our work opens a new avenue to produce 2D BiOCl by tuning the substrate in CVD growth and inspires a new strategy to promote the performance of 2D photocatalysts.

Modulating the Electronic Structure of Cobalt-Vanadium Bimetal Catalysts for High-Stable Anion Exchange Membrane Water Electrolyzer.

Modulating the electronic structure of catalysts to effectively couple the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is essential for developing high-efficiency anion exchange membrane water electrolyzer (AEMWE). Herein, a coral-like nanoarray composed of nanosheets through the synergistic layering effect of cobalt and the 1D guiding of vanadium is synthesized, which promotes extensive contact between the active sites and electrolyte. The HER and OER activities can be enhanced by modulating the electronic structure through nitridation and phosphorization, respectively, enhancing the strength of metal-H bond to optimize hydrogen adsorption and facilitating the proton transfer to improve the transformation of oxygen-containing intermediates. Resultantly, the AEMWE achieves a current density of 500 mA cm-2 at 1.76 V for 1000 h in 1.0 M KOH at 70°C. The energy consumption is 4.21 kWh Nm-3 with the producing hydrogen cost of $0.93 per kg H2. Operando synchrotron radiation and Bode phase angle analyses reveal that during the high-energy consumed OER, the dissolution of vanadium species transforms distorted Co-O octahedral into regular octahedral structures, accompanied by a shortening of the Co-Co bond length. This structural evolution facilitates the formation of oxygen intermediates, thus accelerating the reaction kinetics.

Synthesis, structures, and cytotoxicity insights of organotin(IV) complexes with thiazole-appended pincer ligand

Diorganotin complexes of the compositions [Me2Sn(L)] (1), [n-Bu2Sn(L)] (2), [Ph2Sn(L)]⋅C6H6 (3), [Bz2Sn(L)]⋅C6H6 (4) and [n-Oct2Sn(L)] (5) were synthesized by reacting R2SnO (R = Me, n-Bu, Ph, Bz or n-Oct) with the N2,N6-di(thiazol-2-yl)pyridine-2,6-dicarboxamide (H2L, where H2 denotes the two acidic protons) in refluxing toluene. Additionally, the mono-n-butyltin complex [n-BuSn(HL)Cl2]·H2O (6) was synthesized from n-BuSnCl3 and H2L in acetonitrile. Compounds were characterized by FT-IR, 1H, 13C and 119Sn NMR spectroscopy, while their solid-state structures were examined using single-crystal X-ray diffraction studies. In diorganotin compounds 1–5, the dianionic tridentate ligands (Npy, N−, N−) act as κ-N3 chelators. In 6, the L moiety (O, Npy, N−) acts as a κ-ON2 tridentate chelator, with involvement of one of the carboxamide oxygen atoms. The coordination polyhedron around the Sn(IV) ion is completed either by two axial Sn-R ligands in compounds 1–5 or by n-Bu and Cl ligands in compound 6, giving rise to distorted trigonal bipyramid or octahedral structures, respectively. The tin NMR results show that the penta-coordinated structures of compounds 1–5 and the hexacoordinated structure of compound 6, observed in the solid-state, are retained in solution. The in vitro antitumor activities of 1–5 were tested on T-47D breast cancer cells. Of these, diphenyltin compound 3 showed the highest anti-proliferative effect, with an IC50 of 10 ± 1.60 μM. Compound 3 exhibited selective toxicity, potentially inducing apoptosis via reactive oxygen species generation and nuclear changes, indicating promise as a breast cancer treatment. This study is the first to explore thiazole-appended organotin compounds for cytotoxicity.

Anticancer, Antioxidant and Antimicrobial Evaluation of Cr (III) and Rh(III) Complexes Derived from A New Mannich Base

The Mannich base ligand was synthesized in an ethanol medium through a condensation reaction of 2-mercaptobenzimidazole and ciprofloxacin at room temperature. Subsequently, several metal complexes of this ligand were prepared. To characterize both the base ligand and the metal complexes, various techniques were employed, including elemental analysis, FT-IR spectroscopy, UV-Vis spectroscopy, molar conductivity measurements, magnetic moment determination, and melting point analysis. The results were shown that the metal complexes formed have the formula [Cr(L)2Cl2] Cl.H2O and [Rh(L)2(H2O)2] Cl3.H2O, where L= mannich base ligand. Based on spectroscopic analytical, coordination with metal ions involves the 'N' donor atom of mannich base and 'N' atom of piprizaing ring, and two complexes are A six-coordinated octahedral structure is suggested. Molar conductivity of these complexes showed that they were electrolytic in nature. In this study, the anticancer and antioxidant potential of the Mannich base ligand and its metal complexes were investigated against MDA-MB-231 cell lines and using the DPPH free radical scavenging assay. Moreover, the in vitro efficacy of the ligand and its complexes against Gram-negative bacteria (E. coli) and Gram-positive bacteria (Staphylococcus aureus), as well as the fungal strain Candida albicans, was evaluated using the disc diffusion method. The results indicated that Cr (III) and Rh(III) complexes demonstrated the highest levels of cytotoxicity against MDA-MB-231 cell lines, enhances antioxidant and antimicrobial activity more than the free ligand. These findings suggest that these metal complexes may have promising applications in the development of novel anticancer, antioxidant and antimicrobial agents.

Analysis of Heterostructure Formation of Abnormally Oriented Grains in Sputter-Deposited AlScN Films and Its Impact on Bulk Acoustic Wave Devices.

The presence of abnormally oriented grains (AOGs) in sputter-deposited aluminum scandium nitride (AlScN) films significantly degrades their physical properties, compromising the performance of bulk acoustic wave (BAW) devices. This study utilizes first-principles calculations to reveal that in tetrahedral wurtzite AlScN film-doped Sc atoms tend to aggregate at the second nearest-neighbor positions, forming dense ScN octahedral structures. The rock-salt (RS) ScN continued to grow due to further Sc aggregation. However, due to inadequate scandium flux, embryonic RS structures cannot be sustained, resulting in the nucleation of AOGs at the (111) faces of the octahedral ScN structure. Electron microscopy studies indicated that AOGs possess wurtzite structures and originate at tilted grain boundaries. These boundaries were characterized as RS ScN with more Sc atoms. This corroborated the theoretical predictions. BAW resonators and filters fabricated from sputter-deposited AlScN films demonstrate that AOGs degraded the piezoelectricity of AlScN, reducing the resonator's electromechanical coupling coefficient (Keff2). Measurements showed that AOG density increased from edge to center of the 8 in. wafer, resulting in a 3% decrease in average Keff2 in the resonators and a 137 MHz decrease in the filter bandwidth at 5 dB.

A cubic perovskite fluoride anode with the surface conversion reactions dominated mechanism for advanced lithium-ion batteries.

Perovskite fluorides are attractive anode materials for lithium-ion batteries (LIBs) because of their three-dimensional diffusion channels and robust structures, which is advantageous for the rapid transmission of lithium ions. Unfortunately, the wide band gap results in poor electronic conductivity, which limits their further development and application. Herein, the cubic perovskite iron fluoride (KFeF3, KFF) nanocrystals (~100 nm) are synthesized by a one-step solvothermal strategy. Thanks to the good electrical conductivity of carbon nanotubes (CNTs), the overall electrochemical performance of composite anode material (KFF-CNTs) has been significantly improved. In particular, the KFF-CNTs delives a high specific capacity (363.8 mAh g-1), good rate performance (131.6 mAh g-1 at 3.2 A g-1), and superior cycle stability (500 cycles). Noted that the surface conversion reactions play a dominant role in the electrochemical process of KFF-CNTs, together with the stable octahedral perovskite structure and nanoscale particle sizes achieving high ion diffusion coefficients. Furthermore, the specific lithium storage mechanism of KFF has explored by the distribution of relaxation times (DRT) technology. This work opens up a new way for developing cubic perovskite fluorides as high-capacity and robust anode materials for LIBs.

Theoretical Study on the Mechanism of Ru(II)-Catalyzed Intermolecular [3 + 2] Annulation between o-Toluic Acid and 3,5-Bis(trifluoromethyl)benzaldehyde: Octahedral vs Trigonal Bipyramidal.

Density functional theory was utilized to investigate the mechanism of Ru(II)-catalyzed aromatic C-H activation and addition of aromatic aldehydes. The proposed catalytic cycle consists of C-H bond activation, aldehyde carbonyl insertion for C-C coupling, lactonization for the formation of the final product, product separation, and catalyst recovery. Our calculations suggest that Ru(OAc)2(PCy3) (referred to as CAT) is the most favorable active catalyst, facilitating the C-H bond activation to form a five-membered ring cycloruthenium intermediate (INT2). Subsequently, the aromatic aldehyde reactant 2a enters the Ru coordination sphere, accelerating the C-C coupling and lactonization for the formation of the final product. The involvement of acetate assists in the final product separation, while INT1 re-enters the Ru coordination sphere to initiate a new catalytic cycle. Utilizing the energetic span model, the apparent activation free energy barrier was computed to be 34.3 kcal mol-1 at 443 K. Furthermore, exploration of the reaction mechanism in the absence of phosphine ligands identified Ru(OAc)2(p-cymene) as the most favorable active catalyst. The derived apparent activation free energy barrier offers a comprehensive explanation for the experimentally observed yields. Additionally, we have examined the disparities between the octahedral and trigonal bipyramidal structures of the catalysts concerning their effects on the reaction mechanisms and apparent activation free energy barriers.

Fundamental mechanical relations of open-cell metal foam composite materials with reticular porous structure

The compressive behavior is one of the most fundamental mechanical properties for engineering materials. In this paper, the octahedral structure model of porous materials is used to evolve the mechanical analysis model under compressive loading for the porous composite materials, which are resulted from reticular metal foams with pore struts presenting multilayered structure. Starting from this analysis model, some fundamental mechanical relationships, including those of the safe load-bearing and overall strength, have been deduced for these porous composite materials. The compressive strength has been characterized for the porous composite body, corresponding to the overall failure caused by the prior breakage of the strut core and by the prior breakage of the strut shell, respectively. The nickel foam products manufactured on the production line of enterprise were used to make porous composite materials by coating the pore struts with epoxy resin, and the metal foam composite material was obtained with the composite pore-struts of metal/resin multilayered structure. Using this porous composite material for compression experiments, it is found that the experimental data match well with the mathematical relationship from the present theoretical model. The results verify the feasibility of this analysis model and the practicality of the relevant mathematical relationship.

Design, synthesis, characterization, DFT, molecular docking, and in vitro screening of metal chelates incorporating Schiff base

Hydrazones, with an azomethine -NHN=CH group, are extensively researched due to their easy preparation and numerous pharmaceutical benefits. A hydrazone derivative was formed by combining N,N-dimethyl amino benzaldehyde (1) and hydrazine hydrate (2), producing-4-(methanehydrazonoyl)-N,N-dimethylaniline (3). The final product (H1L) ligand was produced by reacting with ethyl acetate. The new complexes were formed by reacting Co(II), Ni(II), Cu(II), and Zn(II) with the ligand in a 1M:2L molar ratio. Complexes were synthesized with high yields. Metal chelate structures were identified through elemental analyses, FT-IR, magnetic moment, XRD, and molar conductivity tests. According to FT-IR findings, the Schiff base ligand displayed neutral bidentate properties by binding with metal ions via the azomethine N and carbonyl O. Magnetic moment research indicated an octahedral structure and high electrolytic properties, with the exception of Co(II) and Zn(II) complexes, which were observed to be non-electrolytes. Theoretical calculations were performed using DFT. The synthesized complexes were tested for antibacterial activity against two types of Gram-positive bacteria: S. aureus and B. subtilis. Molecular docking analysis revealed information about the ligand's binding energy and interaction with the S. aureus receptor. KEY WORDS: Hydrazinylidene, DFT, Antibacterial activity, Molecular docking Bull. Chem. Soc. Ethiop. 2024, 38(6), 1625-1638. DOI: https://dx.doi.org/10.4314/bcse.v38i6.10

Design, characterizations, DFT, molecular docking and antibacterial studies of some complexes derived from 4-aminpantipyrine with glycine amino acid and ligand

The synthesis of the heterocyclic ligand (LK) involved the combination of 4-amino antipyrine, 4-nitroacetophenone, and glycine. A new series of transition metal complexes of Ni(II), Co(II), Cu(II), and Zn(II) have been synthesized from the Schiff base (LK). It was characterized by micro elemental analysis, FT-IR, UV-Vis, and 1H-NMR spectroscopy. The prepared complexes were characterized using (CHN) analysis, flame atomic absorption, as well as conductivity measurements and magnetic susceptibility. From the obtained data, the octahedral structure was suggested for all complexes. The ligand showed tridentate nature by binding to metal ions through the N atom of antipyrine and the N,O atom of glycine. The exhibited excellent electrolytic properties, except for the Cu(II) and Zn(II) complex which exhibited non-electrolytic behavior. Theoretical calculations with DFT were conducted for all complexes. The antibacterial activity of the ligand and its complexes against (S. aureus, B. subtilis) was evaluated through the disc diffusion method. Additionally, molecular docking analysis was conducted to gain more insights into the ligand's binding energy and interaction with the S. aureus receptor. KEY WORDS: 4-Amino antipyrine, Heterocyclic ligand, Glycine, Molecular docking Bull. Chem. Soc. Ethiop. 2024, 38(6), 1609-1624. DOI: https://dx.doi.org/10.4314/bcse.v38i6.9

Synthesis of 2‐Pyridyl Based N(1)‐Substituted Thiosemicarbazonates of Nickel(II) as Bioactive Materials against MRSA, S. aureus, S. typhimurium 2, and K. pneumonia

AbstractIn this investigation, the bio‐activity and biosafe potential of thiosemicarbazonates of nickel(II) as well as that of ligands are described. Reactions of nickel(II) acetate with a series of thiosemicarbazones, {R1(py)C2=N3‐N2(H)‐C1(=S)‐NHR; R1=py, Me, H and Ph; R=H, Me, Et, Ph}, led to the loss of acidic hydrazinic N2(H) protons, and resulted in the formation of six‐coordinated complexes of stoichiometry, [Ni(N,N,S−L)2], where anionic N,N,S−L=py2tsc‐NHR, 1–4; apytsc‐NHR, 5–8; pytsc‐NHR, 9–12 and bpytsc‐NHR, 13–16. All these complexes have been characterized using analytical data, IR and UV‐visible spectroscopy and ESI‐mass spectrometry. The single crystal X‐ray crystal structure of several complexes {2(Me), 7(Et), 11(Et), 12(Ph), 13(H),14(Me) and 15(Et)} were also determined. Thio‐ligands coordinate to nickel(II) through pyridyl nitrogen‐N4, azomethine nitrogen‐N3 and thiolato sulfur atoms, resulting in the formation of homoleptic complexes with octahedral structures. Complexes 1–16 and uncoordinated thiosemicarbzones, were evaluated for their antimicrobial activity, in terms of ZOI, MIC, time kill assay and in vitro percent cell viability MTT assay, against clinical isolate methicillin‐resistant Staphylococcus aureus (MRSA), Staphylococcus aureus (MTCC740), Klebsiella pneumonia (MTCC109), Salmonella typhimurium (MTCC1251), and Candida albicans (MTCC227), a yeast. Both the ligands and their metal complexes exhibited moderate to high bioactivity, and were found to be biosafe with high cell viability, 88–92 %, in several cases.

Heavy metal ions in polluted water removable by synthesising a new compounds for dithiocarbamate derivatives

Metal ion poisoning in water and industrial effluents threatens ecosystems and human health. The development of efficient metal ion removal technologies has garnered attention in recent years. This work synthesizes and characterizes dithiocarbamate complexes as metal ion scavengers. Used to make dithiocarbamate ligands. Different metal salts were added to carbon disulfide and the proper amines to initiate substitution reactions. The complexes were characterized using FTIR, UV-Vis, mass spectroscopy, 13C-, 1H-NMR, magnetic susceptibility, melting point, and electrical conductivity molar EC. Data from spectroscopy and analysis indicate the development of two-type macrocyclic complexes with the formula [M(L)]2, where M = FeII, CoII, and ZnII ions. Tetrahedral geometries around the metal core and the second general formula [M(L)(H2O)2]2, where M = MnII, NiII, CuII, suggested octahedral structures. Heavy water pollution has been removed using this essential ligand. Metal ion scavenging of 96–98% was possible with the produced dithiocarbamate complexes. This work developed unique and efficient strategies for metal contamination removal from aquatic settings, promising environmental remediation and human health protection. Optimizing synthesis conditions and scaling up operations are needed to fully use these compounds in real-world applications. KEY WORDS: Dithiocarbamate ligand, Transition metal complexes, Spectral characterization, Coordination chemistry, Dithiocarbamate complexes, Scavenger heavy metal ions Bull. Chem. Soc. Ethiop. 2024, 38(6), 1583-1593. DOI: https://dx.doi.org/10.4314/bcse.v38i6.7

Long-acting electrochemical lithium-recovery from original brine using super-stable spinel lithium manganate oxide

with the unprecedented demand for raw lithium, the spinel LiMn2O4 has been widely studied for electrochemical Li-recovery from salt-lake brines, but its industrialization is hindered by the poor cyclability induced by manganese dissolution and Jahn-Teller distortion within octahedral structure. In this work, Cr-doped and carbon-coated LiMn2O4 (C-LMO-Cr) electrodes prepared via coprecipitation-calcination method are employed to improve cycling stability and lithium selectivity for electrochemical Li-recovery. The results confirm the C-LMO-Cr electrode exhibits super-high retention rate of 98.76 % and 95.70 % of the initial capacity (27 mg·g−1) after 300 and 500 cycles, respectively. The carbon buffering on the C-LMO-Cr surface effectively impedes the initial manganese dissolution with the enhanced charge transfer. Moreover, the structural evolution from Raman/XPS analysis and theoretical calculations confirms that the shrinking lattice of the carbon-buffering LMO-Cr enhances Li+ selectivity and Li+ migration. When assembled in a hybrid capacitive deionization (HCDI) device, the optimal C-LMO-Cr electrode displays high adsorption capacity of ∼21 mg·g−1, moderate energy consumption of 13 Wh·mol−1(Li+) with a remarkable increase in Mg/Li ratio from 1.67 to 158 in the original brine from Jiezechaka. Therefore, these results demonstrate a promising potential of C-LMO-Cr electrodes for long-acting electrochemical lithium-recovery from original brines.

Orientation of Co2+ and Cu2+ ions introduced L-type zeolite observed with a magnetic field

L-type zeolite with Co2+ and Cu2+ ions in 3d-transition-metal ions were prepared via ion exchange. The suspension containing these zeolite was used for slip-casting under a 12 T magnetic field applied perpendicular to the substrate surface, resulting in an orientation parallel to the c-axis for Co-L and an orientation vertical to the c-axis for Cu-L. The orientation behavior was strongly affected by the magnetocrystalline anisotropy of the L-type zeolite introduced by Co2+ and Cu2+ ions. X-ray absorption fine structure and diffuse-reflectance measurements indicated that the introduced Co2+ and Cu2+ ions formed six-coordinated hydration complexes in the zeolite structure. These hydrated complexes have a distorted octahedral structure. The results suggest that the stable direction of the magnetic moment of the hydration complex at site B of L-type zeolite depends on the strain direction. The Co2+ and Cu2+ hydration complexes have different strain directions, and the difference in orientation is speculated to be due to the different stable directions of the magnetic moment within the zeolite.

Synthesis Method and Principle of Octahedral Hierarchical LTA Zeolite and Its Application to Enhance Catalytic Activity in Styrene Epoxidation.

A 4 Å zeolite prepared under the synergistic effect of intense ultrasound and a high-voltage electrostatic field had an octahedral structure rather than a conventional hexahedral structure. XPS and XRD analyses showed that the ratio of silicon to aluminum, 2θ peak position, and the corresponding crystal planes were the same as those in traditional hexahedral 4 Å zeolite, but some crystal planes were more prominent. SEM imaging showed that the octahedral zeolites had a larger particle size. Porosimetry (BET surface area and BJH analysis) showed that the octahedral zeolite had become a mesoporous zeolite, and its specific surface area increased and its pore size expanded, which was conducive to loading catalytically active materials and thus improving its catalytic performance. In this paper, the mechanism of formation of hierarchical LTA zeolite is discussed, and the octahedral hierarchical LTA zeolite is used to catalyze the epoxidation of styrene, giving very good results. It is concluded that the (600), (622), (642), and (644) crystal planes played a decisive role in the styrene epoxidation reaction, providing a realistic basis for explaining the crystal plane catalysis effect of the 4 Å zeolite. This new zeolite prepared under the synergistic effect of intense ultrasound and a high-voltage electrostatic field, being the first time to prepare the octahedral hierarchical LTA zeolite, is simple to produce, green, and environmentally friendly and has good economic development prospects compared to the use of templating agents, which not only provides ideas and simpler methods for optimizing the performance of traditional zeolites and developing new zeolites with better performance but also enhances the theoretical basis for preparing new zeolites.

Rational Tailored Polyfluorosubstituted Amide Molecule for Stabilizing PbI6 Framework and Inhibiting Ion Migration Toward Highly Efficient and Stable Perovskite Solar Cells

AbstractPerovskite solar cells (PSCs), while highly efficient, face stability challenges that hinder their commercial application. These instability issues mainly arise from the fragile nature of Pb─I bonds in perovskites, which easily break under environmental stresses such as heat and light, leading to the breakdown of the [PbI6] framework and irreversible degradation. To address these issues, a multifunctional molecule, N1,N4‐bis(2,3,5,6‐tetrafluoro‐4‐iodophenyl)terephthalamide (FIPh‐A), is designed and synthesized to enhance the stability of perovskite films and devices. FIPh‐A molecule possesses carbonyl, amino, and iodotetrafluorophenyl groups that bind and stabilize Pb2+ ions and [PbI6]4− octahedra structure, preventing ion migration in perovskite films. The activation energy of ion migration increases obviously from 0.28 eV to 0.39 eV by adding FIPh‐A verified by experiment results. The residual strain is also released efficiently by introducing FIPh‐A molecule into perovskite films characterized by grazing incidence X‐ray diffraction. The champion PSC with FIPh‐A achieves a power conversion efficiency of 24.60%. After 500 h of continuous illumination (ISOS‐L‐1) and 300 h of thermal aging at 80 °C (ISOS‐D‐2I), these PSCs with FIPh‐A maintained 93% and 77% of their initial efficiency, respectively. These results emphasize the potential of multifunctional additives in overcoming the stability challenges of PSCs, thereby facilitating their commercial advancement.