Octahedral Structure Research Articles

Exploring the Anticancer Activity of Gold Complex with Newly Ligand (DDIBM): Synthesis, Spectral Identification and Magnetic Susceptibility of Its Metallic Complexes

The new heterocyclic ligand, 5-(dimethylamino)-2-(((2-((E)-(4,5-diphenyl-1H-imidazol-2-yl)diazenyl)benzyl)imino)methyl)phenol (DDIBM), was synthesized via the condensation of p-aminobenzylamine with 4,5-diphenyl imidazole, and the resultant compound was condensed with 4-(dimethylamino)-2-hydroxybenzaldehyde. Various instrumental techniques such as mass, 1H-NMR, IR, C.H.N elemental analysis, and UV-vis spectroscopy were used to analyze a newly synthesized ligand. A novel series of complexes was prepared by complexing the ligand with Ni(II), Cu(II), Co(II), and Au(III) and characterized using some of the mentioned techniques. Flame atomic absorption spectroscopy was used to measure the metal ion percentages in the complexes. The magnetic susceptibility and molar conductivity were studied. The electronic spectral data and the magnetic measurement predict the octahedral structure of the complexes except Au(III) complex which has square planer geometry. All complexes showed electrolyte properties. This study aimed to conduct an in vitro cytotoxicity comparative study of DDIBM and its Au(III) complex on human breast cancer cells (MCF-7) and other normal cells. The Au(III) complex was found to be highly selective in targeting cancer cells without affecting normal healthy cells, compared to the ligand. Thus, this complex can be considered as a new drug for treating breast cancer cells (MCF-7), and an attempt in the future to study its effect on other types of cancer.

Synthesis, spectral, antibacterial and NLO properties of organotin(IV) complexes of Thiosemicarbazones and Semicarbazones

In this study, the antimicrobial and nonlinear optical (NLO) response of thiosemicarbazone, semicarbazone, and their organotin(IV) compounds have been investigated. Organotin(IV) complexes of various types, namely [R2Sn(PhTscz)2], [R2Sn(Tscz)2], [R2Sn(Scz)2], [Bu3Sn(PTscz)], [Bu3Sn(PTscz)], and [Bu3Sn(Scz)] (where R = n-Butyl; methyl; PhTsczH = (±) 2-isopropyl-5-methyl-cyclohexylidene)-N-phenylhydrazine-carboxamide, TsczH = (±) 2-isopropyl-5-methylcyclo-hexylidene)hydrazinecarbothioamide, SczH = (±) 2-isopropyl-5-methylcyclohexyli-dene)hydrazine-carboxamide), were synthesized and characterized by CHN analysis, molar conductivity, UV-Vis, FTIR, and NMR (1H, 13C, 119Sn) spectroscopy, along with theoretical evidence obtained through density functional theory (DFT) simulations. The results showed that the Schiff base (HL) ligands acts as a bidentate NO/NS donor with azomethine nitrogen (N) and deprotonated ketonic oxygen/thionic sulphur (O, S) atoms. [R2Sn(L)2] complexes are assigned a distorted octahedral structure, while Bu3Sn(L) complexes have distorted trigonal bipyramidal structures. The B3LYP/LanL2DZ programme theoretically discussed the electronic structure and nonlinear optical (NLO) properties of the synthesized compounds. The synthesised compounds were evaluated for antibacterial activity using the zone inhibition method. Antibacterial activity of the ligands and its metal complexes against Gram(+) and Gram(-) bacteria demonstrated that the organotin complexes are more potentially resistant to microbial activities than the free ligands. According to the reactivity parameter factors, compound Bu2Sn(Scz)2 (3) is less reactive and more stable. Nonlinear optical (NLO) study revealed that compound (3) had greater linear polarizability (α) values, whereas compound Me2Sn(Scz)2 (9) had higher first hyperpolarizability (βtot) values of 244.29 a.u. Because of their high initial hyperpolarizability values, these molecules have excellent non-linear optical properties and can be exploited as innovative materials in the construction of optoelectronic devices.

New phthalazine based nickel (II), cobalt (II), and copper (II) mixed-ligand complexes; characterization, physicochemical properties, anti-inflammatory, antifungal, antibacterial, DFT and molecular docking exploration

In this study, we have employed a straightforward and easily synthesized ligand, namely 1,4-dioxo-3,4-dihydrophthalazine-2(1H)-carbothioamide (DDPC), in conjunction with 8-hydroxyquinoline (QOL) to create new mixed-ligand complex compounds such as Co (II) (C1), Ni (II) (C2), and Cu (II) (C3). Recent research has been dedicated to investigating their antibacterial, antifungal, & anti-inflammatory efficacy. Our approach involved the synthesis and characterization of these novel C1, C2, and C3 mixed-ligand complexes using various analytical methods, having elemental analysis, MS, FT-IR, UV spectroscopy, magnetic, TGA, and stoichiometry analysis by molar ratio methods. Octahedral structures were identified for isolated metal complexes. Utilizing density functional theory (DFT), we estimated the quantum chemical characteristics and optimized molecular structures for each compound. To evaluate their effectiveness in inhibiting the proliferation of harmful microorganisms, a disc diffusion test was conducted. The produced complex compounds displayed meaningfully improved antibacterial & antifungal effectiveness in comparison with the free ligands. Additionally, we investigated the anti-inflammatory effects employing the Egg albumin denaturation method. C1, C2, and C3 complexes demonstrated substantial anti-inflammatory potential, surpassing the free ligands & showing analogous efficacy to standard references. Molecular docking analyses against 5JQ9 and 6CLV from Escherichia coli, Staphylococcus aureus, and COX-2 (5IKT) as an anti-inflammatory effectiveness of enzymes confirmed the bioactivity. Among the tested compounds, C3 exhibited the highest binding affinity, suggesting its potential as a building block for the development of new antibiotics. Finally, we correlated the DFT and molecular docking results with in vitro activities and provided a comprehensive discussion.

The high-impact resistance bionic transparent composite material with octahedral structure

The high-impact resistance bionic transparent composite material with octahedral structure

Effectively enhanced the luminescent properties and water resistance of K2TaF7: Mn4+ red phosphors by introducing In3+ ions in the matrix and constructing a homogeneous core-shell structure

Shell-free K2Ta1-xInxF7: Mn4+ red phosphor was synthesized by introducing In3+ ions in K2TaF7: Mn4+ with a non-centrosymmetric octahedral structure. The strategy of the heterogeneous substitution of In3+ by Ta5+ further distorted the octahedral structure, effectively enhanced the emission intensity of Mn4+. Its overall luminous intensity was increased to 6.9 times that of K2TaF7: Mn4+. Moreover, the red phosphor with a homogeneous core-shell structure was successfully prepared by using a weak reducing agent citric acid to solve the problem of poor water resistance. After soaking in water for 10 days, the emission intensity of the red phosphor with a homogeneous core-shell structure retained 90% of the initial value. It is the first time to successfully construct a core-shell structure for A2BF7: Mn4+ type fluoride phosphors to effectively improve its water resistance. Mixing it with commercial YAG: Ce3+ yellow phosphor and encapsulating them with a commercial blue chip led to the development of warm white light-emitting diodes (WLEDs) with good qualities. K2Ta1-xInxF7: Mn4+ red phosphor with homogeneous core shell is a novel red phosphor with good luminous performances and excellent water resistance.

The hollow cubic octahedral structure of Fe3O4 with excellent electromagnetic wave absorption capacity

The unique nanostructure combined with high dielectric and magnetic losses is essential for electromagnetic wave (EMW) attenuation in microwave-absorbing materials (MAM). In this paper, using cubic octahedral Cu2O as a template, we synthesized hollow cubic octahedral Fe(OH)3 at first. After annealing at 450 °C, the hollow cubic octahedral structure Fe3O4 could be obtained. When the filling ratio was 40 %, the minimum reflection loss (RLmin) reached -66.08 dB, and the maximum effective absorption bandwidth (EAB) was 5.38 GHz at a thickness of 1.84 mm, exhibiting improved EMW properties compared with previous works. The hollow cubic octahedral structure of Fe3O4 enhances EMW absorption characteristics, which is attributed to abundant dipole polarization, interface polarization, and good conduction loss. These results indicate that Fe3O4 with the hollow cubic octahedral structure can be used as potential candidates for efficient and broadband EMW absorbers.

Synthesis, Characterization and Evaluation of the Antimicrobial and Herbicidal Activities of Some Transition Metal Ions Complexes with the Tranexamic Acid.

New tranexamic acid (TXA) complexes of ferric(III), cobalt(II), nickel(II), copper(II) and zirconium(IV) were synthesized and characterized by elemental analysis (CHN), conductimetric (Λ), magnetic susceptibility investigations (μeff), Fourier transform infrared (FT-IR), proton nuclear magnetic resonance (1H-NMR), ultraviolet visible (UV-vis.), optical band gap energy (Eg) and thermal studies (TG/DTG and DTA). TXA complexes were established in 1 : 2 (metal: ligand) stoichiometric ratio according to CHN data. Based on FT-IR and 1H-NMR data the disappeared of the carboxylic proton supported the deprotonating of TXA and linked to metal ions via the carboxylate group's oxygen atom as a bidentate ligand. UV-visible spectra and magnetic moment demonstrated that all chelates have geometric octahedral structures. Eg values indicated that our complexes are more electro conductive. DTA revealed presence of water molecules in inner and outer spheres of the complexes. DTA results showed that endothermic and exothermic peaks were identified in the degradation mechanisms. The ligand and metal complexes were investigated for their antimicrobial and herbicidal efficacy. The Co(II) and Ni(II) complexes showed antimicrobial activity against some tested species. The obtained results showed a promising herbicidal effect of TXA ligand and its metal complexes particularly copper and zirconium against the three tested plants.

Enhancing dye-sensitized solar cell performance: Optimizing Cu2ZnSnS4/ZnCo2O4 nanocomposites as efficient and cost-effective counter electrodes

This study investigates the utilization of Cu2ZnSnS4/ZnCo2O4 (CZTS/ZCO) nanocomposites prepared through hydrothermal and combustion methods as counter electrodes in Dye-Sensitized Solar Cells (DSSCs). Different ratios of Cu2ZnSnS4 and ZnCo2O4 were explored, and comprehensive analyses were conducted using X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), High-Resolution TEM (HRTEM), Brunauer–Emmett–Teller (BET) surface area analysis, Raman Spectroscopy, Electrochemical Impedance Spectroscopy (EIS), cyclic voltammetry (CV), Tafel analysis, Field Emission Scanning Electron Microscopy (FESEM), and Incident Photon-to-Electron Conversion Efficiency (IPCE), alongside long-term stability assessments. The CZTS:ZCO ratio of 2:1 exhibited the highest efficiency, reaching 8.81 %, with an open-circuit voltage of 729 mV, short-circuit current of 17.80 mAcm−2, and a fill factor of 67.9 %. This surpasses the efficiency of the reference Pt cell (8.42 %), which had an open-circuit voltage of 735 mV, short-circuit current of 17.16 mAcm−2, and a fill factor of 66.8 %. The average crystallite sizes for the main peaks of CZTS and ZCO samples were estimated to be 19.8 and 16.7 nm, respectively. The crystallite size can significantly affect the charge transfer and conductivity in the counter electrode during electrochemical processes; the presence of nanocrystals with these sizes can notably enhance the electrochemical properties and conductivity of the synthesized samples. Raman analysis results indicate that no additional phases or secondary phases such as ZnS and CuSnS3 have formed in the kesterite CZTS structure, and the crystal has formed as a single phase. Additionally, the F2g modes in the Raman spectrum of ZCO indicate tetrahedral units in the spinel ZCO structure, and the A1g modes represent octahedral structures in this phase, indicating the formation of suitable ZCO phase. The superior performance of the CZTS/ZCO nanocomposite can be attributed to its enhanced crystalline structure, superior charge transport characteristics, and improved electrocatalytic behaviours.

Comprehensive investigation on fabrication, spectral characterization and biological importance of Co(II) and Ni(II) heteroleptic complexes

Using the microwave irradiation approach, novel metallic complexes of Cobalt [Co(II)] and Nickel [Ni(II)] complexes of 2-aminothiazole (ATZ) and thiocyanate ligands [IUPAC Name: Di(2-aminothiazole) thiocyanato cobalt(II), Di(2-aminothiazole) thiocyanato nickel(II)] were created. The molecular formulas and the geometry of the complexes have been deduced by elemental analysis, molar conductance, magnetic moment, UV–visible, FT-IR, thermogravimetric analysis, cyclic voltammetry, and powder-XRD techniques. Molar conductance values indicate that the complexes are non-electrolyte (1:0) type. The complexes have octahedral structure is revealed by the magnetic moment and UV–visible spectra. The FT-IR spectra reveal that the 2-aminothiazole and thiocyanate ions are coordinated to the metal ion in a monodentate manner. The antibacterial capabilities of ligands and their Co(II) and Ni(II) compounds were studied against a restricted set of microorganisms utilizing the agar-well diffusion method and varying concentrations.When compared to free 2-aminothiazole ligand, the complexes exhibit possible activity against the fungus than bacteria. By assessing how well the complexes and ligands interact with the stable free radical DPPH, their ability to scavenge free radicals has been established. Comparing the complexes to the free ligand, the complexes exhibit greater antioxidant activity due to the fact that metal complexes are widely recognized for their capacity to accelerate medication action and boost therapeutic agent potency when they coordinate with a metal ion. The primary goal of this research is to develop multimodal medicinal drugs, which include studying the roles of 2-aminothiazole and its transition metal complexes.

Synthesis, Characterization (I.R, Elemental analysis, Molar Conductivity), and Antibacterial Investigation of Complex produced by the reaction between Co (II) ion with mixed ligands of (Amoxicillin and Salen)

The complex of cobalt (II) was prepared with the mixed ligand (amoxicillin and salen), and the formed complex was characterized using infrared (I.R.) spectroscopy, elemental analysis of (C%, H%, N%, and M%), molar conductivity methods, and melting point to characterize the complex. The results indicated that the complex is relatively insoluble in aqueous solutions and has significant antibiotic activity against colon bacteria. They also showed that the mixed complex formed has an octahedral structure and has a good electrolytic nature.

Enhanced charge separation of Cu-BTC@CuSe@TiO2 hollow octahedrons for efficient CO2 photoreduction with superior CO selectivity

Solar-driven photocatalytic conversion of CO2 into high-value-added fuels has attracted widespread attention. However, the relatively low conversion efficiency and product yield severely limited photocatalytic applications. In this work, binary Cu-BTC@TiO2 catalysts with adjustable inner cavity were prepared using copper-based metal organic framework (Cu-BTC) octahedrons as substrate via a solvothermal reaction. In this process, the inner Cu-BTC octahedrons can be controllably etched into a hollow octahedral structure in the presence of HF. Subsequently, the Cu-BTC@CuSe@TiO2 hollow octahedrons (HOs) were fabricated by selenization reaction and exhibited various properties such as abundant active sites for CO2 adsorption and reduction reactions, shortened charge transfer distance to prevent electron-hole recombination, and internal reflection/scattering effects to improve solar light utilization. Moreover, the formed dual p-n heterostructures between p-type CuSe and n-type semiconductors (Cu-BTC and TiO2) effectively promote spatial separation and migration of charge carriers. The synergistic effect of these advantages makes the optimized Cu-BTC@CuSe@TiO2 HO catalyst exhibit remarkable CO2 photoreduction performance with a CO production rate of 72.3 μmol h−1 g−1 and near 100 % selectivity. This work opens a new pathway for designing highly active photocatalysts with excellent product selectivity.

Co(II) and Ni(II) complexes with bis(4-((E)-(4,5-diphenyl-1H-imidazol-2-yl)diazenyl) phenyl)methane: synthesis, characterization and anti-corrosion effect investigation

Bright coloured Co (II) and Ni (II) complexes of an azo ligand were synthesized. This ligand was previously synthesized from the coupling reaction between 4,5-diphenyl imidazole and 4,4-diaminodiphenylmethane in 1:2 molar ratio (4,4-diaminodiphenylmethane and 4,5-diphenyl imidazole). The synthesis process of the complexes involved the reflux reaction between the azo ligand with both metal salts. The synthesized complexes were characterized by FTIR, UV.-Visible, molar conductivity and atomic absorption. From the obtained characteristic data of the FTIR spectra, the coordination between the two metals and the azo ligand occurs by the coordination with the nitrogen atom of the azo group and one of the nitrogen atoms in the imidazole both rings. The molar conductivity test confirm the non- electrolytic nature of both complexes, while the atomic absorption agrees with the expected complexes formula. Therefore, the octahedral structure for the two complexes is suggested. The anti-corrosion activity of the synthesized compounds were investigated under two temperatures (298 and 308 K) with 0.03 gm of each compound was tested. According to the results cobalt (II) complex shows a better anti-corrosion activity (93%) in comparison with the ligand and nickel (II) complex. KEY WORDS: Cobalt(II) and nickel(II) azo complexes, Imidazole derivative, Anti-corrosion effect Bull. Chem. Soc. Ethiop. 2024, 38(4), 963-971. DOI: https://dx.doi.org/10.4314/bcse.v38i4.12

Exploring orientation-dependent interface engineering in manganite heterostructures

The crucial role of interface engineering in controlling functionality has been well documented in the (001)-orientated perovskite oxide heterostructures; however, limited attention has been given to other epitaxial orientations. In this study, the (La,Sr)MnO3 heterostructure is selected to present the epitaxial-orientation-dependent interface engineering strategies based on magnetoelectric coupling and oxygen octahedral coupling. When capped by a ferroelectric PbTiO3 layer for interlayer magnetoelectric coupling, the (001) (La,Sr)MnO3 layer exhibits the most significant magnetic modulations compared to (110) and (111) counterparts. This can be attributed to the PbTiO3's out-of-plane polarization that depends on the epitaxial orientations. Also, if considering the interfacial oxygen octahedral structure in terms of epitaxial orientations, the buffer (or cap) layer hosts the most part of interfacial oxygen octahedra and, thus, plays a dominant role in controlling oxygen octahedral coupling of (001)-orientated [or (110)-orientated] perovskite heterostructures. This is consistent with our observations that for the (001) [or (110)] (La,Sr)MnO3 heterostructures, the DyScO3 buffer layer offers the more (or less) effective magnetic modulations compared to the cap one. These findings underscore the orientation-dependent nature of interface engineering in manganite heterostructures as well as in other perovskite heterostructures for tailoring functionalities.

Development and Characterization of a Remanufactured Motorcycle Clutch Hub from End-of-Life Aluminium Alloy

This study aims to employ reverse engineering in the development of the Yamaha CY 80 motorcycle clutch hub using end-of-life (EOL) aluminium alloy obtained from automotive vehicle scraps. The remanufactured motorcycle clutch hub underwent characterization and transient thermal analysis by integrating the geometric and structural features of the clutch hub. The EOL aluminium was thoroughly washed with a sodium hydroxide (NaOH) solution, cleaned with running water, and dried under sunlight to remove impurities trapped on the metal surfaces. The EOL aluminium alloy was melted in a gas furnace, and the molten metal was cast into the clutch hub using a permanent mold designed with the geometric features and characteristics of the Yamaha CY 80 motorcycle clutch hub. The EOL aluminium alloy was characterized using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). The remanufactured CAD model of the Yamaha CY 80 motorcycle clutch hub was subjected to transient thermal analysis using ANSYS Workbench to predict the thermal behavior of the clutch hub during operation. The FTIR spectra exhibited the following distinctive bands: Al-O stretching modes in octahedral and tetrahedral structures, as well as symmetric bending of Al-O-H, with wavenumbers between 340 and 3131 cm-1 for -OH bonds and between 2109 and 1688 cm-1 for H-O-H bonds. The SEM-EDS micrographs indicated that the two main elements were bromine and silicon. Results from the transient thermal analysis indicated that the minimum and maximum temperatures were 40.109 °C and 250.09 °C within a time frame of 240 seconds. The maximum total heat flux was 30,271,000 W/m2. The compressive yield strength and tensile yield strength obtained in this study were 280 MPa, while the ultimate tensile strength was measured at 310 MPa. The alternating stress levels ranged from 62.05 MPa to 275.8 MPa. This study established that the material is susceptible to fatigue failure, as the alternating stress levels were below the material’s yield strength of 280 MPa.

Effects of Fe(II) bio-oxidation rate and alkali control on schwertmannite microstructure and adsorption of oxyanions: Characteristics, performance and mechanism

Schwertmannite has attracted increasing interest for its excellent sorption of oxyanions such as AsO43−, CrO42−, and Sb(OH)6−. Controlling biomineralization by adjusting the Fe(II) oxidation rate and implementing alkali control can enhance the yield and adsorption performance of schwertmannite. However, the adsorption improvement mechanism is still unclear. The morphology, crystallinity, specific surface area (SSA) and oxyanion adsorption of schwertmannite synthesized with alkali control of solution pH and different Fe(II) oxidation rates were analyzed in this study. The differences in the adsorption mechanisms of As(V), Cr(VI) and Sb(V) on schwertmannite obtained under different synthesis conditions were also studied. Reducing the Fe(II) oxidation rate or maintaining the solution pH through alkali control significantly increased the SSA of schwertmannite and the proportion of outer-sphere sulfate. Alkali-controlled schwertmannite (Sch-C) exhibited superior As(V) and Sb(V) adsorption performance and slightly greater Cr(VI) adsorption than non-alkali-controlled schwertmannite. The As(V) and Sb(V) adsorption capacities of Sch-C greatly improved because the ultra-high SSA increased the surface hydroxyl content and reduced the passivation effect of amorphous precipitates on the mineral surface, allowing continuous sulfate exchange at inner mineral sites. An increased surface hydroxyl content had little effect on Cr(VI) adsorption, but an increased proportion of outer-sphere sulfate caused a slight increase in Cr(VI) adsorption. Sb(V) has a stronger hydroxyl exchange ability than As(V), but due to its octahedral structure, it exchanges only with outer-sphere sulfate on schwertmannite and hardly exchanges with inner-sphere sulfate.

Controllable Regulation of the Oxygen Redox Process in Lithium-Oxygen Batteries by High-Configuration-Entropy Spinel with an Asymmetric Octahedral Structure.

Designing bifunctional electrocatalysts to boost oxygen redox reactions is critical for high-performance lithium-oxygen batteries (LOBs). In this work, high-entropy spinel (Co0.2Mn0.2Ni0.2Fe0.2Cr0.2)3O4 (HEOS) is fabricated by modulating the internal configuration entropy of spinel and studied as the oxygen electrode catalyst in LOBs. Under the high-entropy atomic environment, the Co-O octahedron in spinel undergoes asymmetric deformation, and the reconfiguration of the electron structure around the Co sites leads to the upward shift of the d-orbital centers of the Co sites toward the Fermi level, which is conducive to the strong adsorption of redox intermediate LiO2 on the surface of the HEOS, ultimately forming a layer of a highly dispersed Li2O2 thin film. Thin-film Li2O2 is beneficial for ion diffusion and electron transfer at the electrode-electrolyte interface, which makes the product easy to decompose during the charge process, ultimately accelerating the kinetics of oxygen redox reactions in LOBs. Based on the above advantages, HEOS-based LOBs deliver high discharge/charge capacity (12.61/11.72 mAh cm-2) and excellent cyclability (424 cycles). This work broadens the way for the design of cathode catalysts to improve oxygen redox kinetics in LOBs.

Arising 2D Perovskites for Ionizing Radiation Detection.

2D perovskites have greatly improved moisture stability owing to the large organic cations embedded in the inorganic octahedral structure, which also suppresses the ions migration and reduces the dark current. The suppression of ions migration by 2D perovskites effectively suppresses excessive device noise and baseline drift and shows excellent potential in the direct X-ray detection field. In addition, 2D perovskites have gradually emerged with many unique properties, such as anisotropy, tunable bandgap, high photoluminescence quantum yield, and wide range exciton binding energy, which continuously promote the development of 2D perovskites in ionizing radiation detection. This review aims to systematically summarize the advances and progress of 2D halide perovskite semiconductor and scintillator ionizing radiation detectors, including reported alpha (α) particle, beta (β) particle, neutron, X-ray, and gamma (γ) ray detection. The unique structural features of 2D perovskites and their advantages in X-ray detection are discussed. Development directions are also proposed to overcome the limitations of 2D halide perovskite radiation detectors.

Nickle ion surface engineered MOF derived α-Fe2O3 octahedrons for high efficiency toluene detection with high moisture resistance and long-term stability

Metal-organic framework derivatives have become very promising candidates for gas sensors due to their advantages of large specific surface area, many surface active sites, and tunable properties. Meanwhile, Ni ion doping is an effective technique to enhance the moisture resistance of sensing materials. Inspired by this, in this work, we have successfully synthesized porous octahedral structures of Ni-Fe2O3 derived from metal-organic frameworks by in situ doping, in which the Ni contents were 0.4, 0.5 and 0.6 mol%, respectively. Notably, Ni doping changes the conductive type of Fe2O3 from n-type to p-type with a significant decrease in resistance. At the same time, the sensing performance of Fe2O3 octahedrons for volatile organic compound gases, especially toluene, is greatly improved. The 0.5 mol% Ni doped Fe2O3 sensor showed the highest response to toluene at 225°C (100 ppm, 47), which is five times higher than the pristine Fe2O3 (response 9.5). In addition, the sensor demonstrated fast response and recovery time (20 s/40 s), low detection limit (200 ppb), high moisture tolerance (98% RH, 47), and long-term stability of over 60 days. The main reason for the exceptional performance of Ni doped Fe2O3 sensors is its special porous octahedral structure, and more importantly, the change of carrier type of the sensing material after Ni doping and the substantial increase of oxygen vacancies, and the catalytic effect of Ni ions.

Bi‐Functional Chelating Ligand Enables Ultra‐Stable Blue Emissive CsPbBr3 Nanoplatelets Film

AbstractQuantum‐confined perovskite CsPbBr3 Nanoplatelets (NPLs) have recently emerged as promising blue‐emitting materials for perovskite light‐emitting diodes (PeLEDs). Yet, their susceptibility to optical instability in solid films under ambient conditions poses a significant hindrance. This study introduces a novel chelating strategy that utilizes metal manganese ions and multidentate ligands, markedly improving the structural stability, and emission efficiency of NPLs. The approach involves adding Diethylenetriaminepentaacetic acid (DTPA) to the perovskite precursor solution, which allows for strong coordination to surface [PbBr6]4− octahedrons via its multiple chelation sites. Ensuing metal manganese ion integration during the purification phase addresses Pb2+ and Br− site vacancies, culminating in near‐perfect octahedral structures with significantly fewer vacancies. These metal manganese ions are then further immobilized on the NPLs surface by the chelating effect of unbound DTPA functional groups. The resultant CsPbBr3 NPLs films demonstrate an impressive PLQY of 66%, showcasing remarkable air stability with consistent blue emission for up to 5 days. The CsPbBr3 NPLs‐based PeLEDs show electroluminescence at 460 nm with a current efficiency of 1.07 cd A−1 and a maximum luminance of 220 cd m−2. The proposed chelating strategy positions perovskite NPLs as an extremely promising prospect in future applications of high‐definition displays and high‐quality lighting.

Elucidating Electrochemical Energy Storage Performance of Unary, Binary, and Ternary Transition Metal Phosphates and their Composites with Carbonaceous Materials for Supercapacitor Applications

Transition metal compounds (TMCs) are being researched as promising electrode materials for electrochemical energy storage devices (supercapacitors). Among TMCs, transition metal phosphates (TMPs) have good, layered structures owing to open framework and protonic exchange capability among different layers, good surface area due to engrossed porosity, rich active redox reaction sites owing to octahedral structure and variable valance metallic ions. Hence TMPs become more ideal for supercapacitor electrode materials compared to other TMCs. However, TMPs have got some issues like low conductivity, rate performance, stability, energy, and power densities. But these problems can be addressed by making their composites with carbonaceous materials, e.g., carbon nanotubes (CNTs), graphene oxide (GO), graphitic carbon (GC), etc. A few factors like high surface area, excellent electrical conductivity of carbon materials and variable valence metal ions in TMPs caused great enhancement in their electrochemical performance. This article tries to discuss and compare the published data, majorly in last decade, regarding the electrochemical energy storage potential of pristine unary, binary, and ternary TMPs and their hybrid composites with carbonaceous materials (CNTs, GOs/rGOs, GC, etc.). The electrochemical performance of the hybrids has been reported to be higher than the pristine counterparts. It is hoped that the current review will open a new gateway to study and explore the high performance TMPs based supercapacitor materials.