Inorganics, Volume 12, Issue 4 (April 2024) – 33 articles

Lithium perchlorate-doped polypyrrole growing on titanium substrate (LiClO₄-PPy/Ti) has been fabricated to act as electroactive electrode material for feasible electrochemical energy storage. A theoretical and experimental investigation is adopted to disclose the conductivity, electroactivity properties and interfacial interaction-dependent capacitance of LiClO₄-PPy/Ti electrode. The experimental measurement results disclose that LiClO₄-PPy/Ti reveals lower ohmic resistance (0.2226 Ω cm⁻²) and charge transfer resistance (2116 Ω cm⁻²) to exhibit higher electrochemical conductivity, a more reactive surface, and feasible ion diffusion to present higher double-layer capacitance (0.1930 mF cm⁻²) rather than LiClO₄/Ti (0.3660 Ω cm⁻², 65,250 Ω cm⁻², 0.0334 mF cm⁻²). LiClO₄-PPy/Ti reveals higher Faradaic capacitance caused by the reversible doping and dedoping process of perchlorate ion on PPy than the electrical double-layer capacitance of LiClO₄/Ti caused by the reversible adsorption and desorption process of the LiClO₄ electrolyte on Ti. Theoretical simulation calculation results prove that a more intensive electrostatic interaction of pyrrole N···Ti (2.450 Å) in LiClO₄-PPy/Ti rather than perchlorate O···Ti (3.537 Å) in LiClO₄/Ti. LiClO₄-PPy/Ti exhibits higher density of states (57.321 electrons/eV) at Fermi energy and lower HOMO-LUMO molecule orbital energy gap (0.032 eV) than LiClO₄/Ti (9.652 electrons/eV, 0.340 eV) to present the enhanced electronic conductivity. LiClO₄-PPy/Ti also exhibits a more declined interface energy (−1.461 × 10⁴) than LiClO₄/Ti (−5.202 × 10³ eV) to present the intensified interfacial interaction. LiClO₄-PPy/Ti accordingly exhibits much higher specific capacitances of 0.123~0.0122 mF cm⁻² at current densities of 0.01~0.10 mA cm⁻² rather than LiClO₄/Ti (0.010~0.0095 mF cm⁻², presenting superior electroactivity and electrochemical capacitance properties. LiClO₄-PPy/Ti could well act as the electroactive supercapacitor electrode for feasible energy storage. Full article

Prussian blue analogues (PBAs) have recently emerged as effective materials in different functional applications, ranging from energy storage to electrochemical water splitting, thence to more “traditional” heterogeneous catalysis. Their versatility is due to their open framework, compositional variety, and fast and efficient internal charge exchange, coupled with a self-healing ability that makes them unique. This review paper presents and discusses the findings of the last decade in the field of the catalytic and photocatalytic application of PBAs in water remediation (via the degradation of organic pollutants and heavy metal removal) and the catalytic oxidation of organics and production or organic intermediates for industrial synthesis. Analysis of the catalytic processes is approached from a critical perspective, highlighting both the achievements of the research community and the limits still affecting this field. Full article

In this study, a novel systematic analysis was conducted to explore the impact of various parameters, including acceptor density (N_A), individual layer thickness, defect density, interface defect density, and the metal electrode work function, on efficiency within the FTO/ZnO/CsSnI₃/NiO_x/Au perovskite solar cell structure through the SCAPS-1D (Solar Cell Capacitance Simulator in 1 Dimension) simulation. ZnO served as the electron transport layer (ETL), CsSnI₃ as the perovskite absorption layer (PAL), and NiO_x as the hole transport layer (HTL), all contributing to the optimization of device performance. To achieve the optimal power conversion efficiency (PCE), we determined the ideal PAL acceptor density (N_A) to be 2 × 10¹⁹ cm⁻³ and the optimal thicknesses to be 20 nm for the ETL (ZnO), 700 nm for the PAL (CsSnI₃), and 10 nm for the HTL (NiO_x), with the metal electrode remaining as Au. As a result of the optimization process, efficiency increased from 11.89% to 23.84%. These results are expected to contribute to the performance enhancement of eco-friendly, lead-free inorganic hybrid solar cells with Sn-based perovskite as the PAL. Full article

Select triphenyl stannanes bearing either a formally sp² or sp³ hybridized amine, viz 2-(pyC₂H₄)SnPh₃ (2: py = pyridinyl), 4-(pyC₂H₄)SnPh₃ (3), 2-(pzC₂H₄)SnPh₃ (4: pz = pyrazyl), and Me₂N(CH₂)₃SnPh₃ (6), were prepared and characterized by NMR spectroscopy (¹¹⁹Sn, ¹³C, ¹H), and additionally, in the case of 2, by single crystal X-ray diffraction. Bromination of 2 to yield 2-(pyC₂H₄)SnPhBr₂ (8) was achieved in good yield. X-ray crystallographic analysis of 8 revealed two unique molecules with 5-coordinate Sn centers featuring Sn-N distances of 2.382 (5) and 2.363 (5) Å, respectively. The calculated structures of the non- and hypercoordinating C,N-stannanes (1–9) were in good agreement with available crystallographic data. The relative stabilities of hyper- and non-hypercoordinating conformers obtained from conformational sampling were determined by comparison with reference conformers and by natural bond orbital (NBO) energetic analyses. Reduction of 8 to the dihydride species, 2-(pyC₂H₄)SnPhH₂ (9), and subsequent conversion to the polystannane, -[2-(pyC₂H₄)SnPh]_n- (15), by transition metal-catalyzed dehydropolymerization was also achieved. Evidence for the decomposition of 15 into a redistributed distannoxane, {2-(pyC₂H₄)SnPh₂}₂O (16), was also observed. Full article

In recent years, there has been a significant focus on the green synthetization of metal oxide nanoparticles due to their environmentally friendly features and cost-effectiveness. The aim of this study is to biosynthesize zinc oxide nanoparticles (ZnO NPs) through a green method, utilizing crude banana peel extract as reducing and capping agents, to characterize the synthesized ZnO NPs and test their antibacterial activity. ZnO NPs were biosynthesized using the peel extract of banana with various concentrations of zinc acetate dihydrate salt, followed by annealing at 400 °C for 2 h. The synthesized ZnO NPs were characterized using UV–visible spectroscopy (UV-Vis), scanning electron microscopy (SEM), dynamic light scattering (DLS), attenuated total reflectance–Fourier-transform infrared (ATR-FTIR), and X-ray diffraction (XRD). Also, its antibacterial efficiency against different bacterial strains was tested. ZnO NPs were biosynthesized successfully using the extract of Musa Acumniata (cavendish) fruit peel with a UV-Vis wavelength range of 344 to 369 nm and an electrical band gap ranging from 3.36 to 3.61 eV. The size varied from 27 ± 4 nm to 89 ± 22, and the negative zeta potential (ζ) ranged from −14.72 ± 0.77 to −7.43 ± 0.35 mV. ATR-FTIR analysis showed that the extract phytochemical functional groups were present on ZnO NPs. XRD results confirm the formation of a highly pure wurtzite hexagonal structure of ZnO NPs. Moreover, the best obtained size of ZnO NPs was selected for the antibacterial tests, giving the highest inhibition growth rate against Staphylococcus epidermidis (98.6 ± 0.9%), while the lowest rate was against Pseudomonas aeruginosa (88.4 ± 4.4%). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were reported and compared to previous studies. The unique properties of greenly synthesized ZnO NPs and their antibacterial activity have potential for reducing environmental pollution and the use of antibiotics, which may contribute to solving the problem of bacterial resistance. Therefore, studies that aim to design an applicable dosage form loaded with biosynthesized ZnO NPs might be conducted in the future. Full article

In this study, TiC particle-reinforced Cu-based composites were prepared by powder metallurgy and spark plasma sintering (SPS) techniques. The mechanical and electrical properties of TiC/Cu composites were analyzed in conjunction with micro-morphology. The results showed that: TiC was fully diffused in the Cu matrix at a sintering temperature of 900 °C. The micron-sized TiC particles were most uniformly distributed in the Cu matrix and had the best performance. At this time, the densification of 5 wt.% TiC/Cu composites reached 97.19%, and the conductivity, hardness, and compressive yield strength were 11.47 MS·m⁻¹, 112.9 HV, and 162 MPa, respectively. The effect of TiC content on the overall properties of the composites was investigated at a sintering temperature of 900 °C. The TiC content of the composites was also found to have a significant influence on the overall properties of the composites. The best performance of the composites was obtained when the TiC mass fraction was 10%. The average values of density, hardness, yield strength and conductivity of the 10 wt.% TiC/Cu composites were 90.07%, 128.3 HV, 272 MPa and 9.98 MS·m⁻¹, respectively. The yield strength was 272 MPa, and the compressive strain was 38.8%. With the increase in TiC content, although the yield strength increased, the brittleness increased due to more weak interfaces in the composites. Full article

Since semiconductor-based photocatalysis uses solar energy as a free and sustainable energy source and inoffensive photocatalysts, it has been found to be a promising green approach to eliminating dyes, antibiotics, and other pharmaceuticals from water that has been contaminated. In this study, a distinctive magnetic separable Fe₃O₄-ZnO:V photocatalyst is reported. ZnO:V semiconductors have been produced by seed-assisted growth over preformed magnetite to develop Fe₃O₄-ZnO:V nanocomposites. The results indicated nanocomposites with the structure of Fe₃O₄, ZnO:V, according to the findings of the XRD, XPS, and HRTEM investigations. Additionally, magnetic studies revealed at room temperature, the nanocomposite exhibited superparamagnetic properties. Electrochemical Impedance Spectroscopy (EIS) was employed to characterize the ability of the Fe₃O₄-ZnO:V nanocomposites to transfer electrons. Furthermore, the impact of dopant on optical characteristics was evaluated. When exposed to rhodamine B (RhB), all the samples exhibited photocatalytic activity. Through the use of an ESR experiment and the spin-trapping technique, the existence of reactive oxygen species (ROS) at the solid–liquid interface was demonstrated, and their impact on the samples’ photocatalytic activity was highlighted. After recycling, XRD, XPS, and SEM were performed to illustrate the stability of the material. The impact of V doping on the morphologic, structural, and compositional properties of magnetically separable Fe₃O₄-ZnO:V composite nanoparticles for photocatalytic applications is the innovative aspect of our work. Full article

Hybrid siloxane materials based on a mutually reactive epoxy–amine system are organic-inorganic hybrid materials synthesized via the sol–gel reaction of siloxane precursors, followed by the polymerization of organo-functionalized oligosiloxanes. Therefore, using a new hybrid system as the reaction product resulting from the reaction between 1,3-bis(3-glycidoxypropyl)-l, 1,3,3-tetramethyldisiloxane—C₁₆H₃₄O₅Si₂—(gp-DS) and p-phenylenediamine—C₆H₄(NH₂)₂—(PPD), an aromatic diamine, was obtained. The chemical structure of the synthesized hybrid siloxane material was confirmed via Fourier Transform Infra-Red (FTIR) spectroscopy, mass spectrometry (MS), and ¹H-NMR spectroscopy. The morphology and surface chemical composition was highlighted via scanning electron microscopy (SEM) equipped with an EDX elemental analysis system. Further, the thermal stabilities of the prepared hybrid siloxane and its precursors have been investigated via thermogravimetric analysis (TGA), proving the modification of epoxy-functional disiloxanes with a paraphenylenediamine reagent that made it possible to produce hybrid siloxane materials with very good thermal stabilities and dual weak hydrophilic/hydrophobic surfaces. Full article

This study presents the synthesis and electrochemical evaluation of nitrogen-doped vanadium oxide (N−V₂O₃/C) as a cathode material for aqueous zinc-ion batteries (AZIBs), using a hydrothermal method. Compared to undoped V₂O₃/C, N−V₂O₃/C exhibits enhanced electrical conductivity, capacity, and electrochemical kinetics, attributed to the incorporation of pyridinic and pyrrolic nitrogen. The initial charge–discharge cycles indicate phase transitions to amorphous vanadium oxides, enhancing conductivity. N−V₂O₃/C shows a high specific capacity of 168.4 mAh g⁻¹ at 10 A g⁻¹ and remarkable reversibility, highlighted by the transient existence of intermediate species during cycling. Optimal electrochemical performance is achieved with a vanadium-to-nitrogen molar ratio of 2:3, indicating the significant impact of the nitrogen doping concentration on the material’s efficiency. This work underscores the potential of N−V₂O₃/C as a superior cathode material for AZIBs. Full article

This study comprehensively characterizes synthesized phosphate materials, specifically A₂MnP₂O₇ (where A represents Na, K, or Li), utilizing the X-ray diffraction (XRD) and infrared (IR) spectroscopy techniques. The XRD results corroborate the crystalline nature of these compounds, while the IR spectra disclose pivotal structural characteristics, including the bent geometry of the POP bridge. A significant observation is the mismatch of specific IR bands, suggesting a non-centrosymmetric arrangement in the A₂MnP₂O₇ crystal lattice. The synthesized materials were evaluated as corrosion inhibitors for mild steel (MS) in 3 wt.% NaCl. Electrochemical assessments indicate that these materials act as mixed-type inhibitors, demonstrating high inhibition efficiencies (η%), reaching peak values of 88.3% for Na₂MnP₂O₇, 87% for K₂MnP₂O₇, and 86.7% for Li₂MnP₂O₇ at a concentration of 10⁻³ mol/L. The study also elucidates the thermodynamic and kinetic parameters dictating the inhibition phenomena. Additionally, scanning electron microscopy (SEM) was employed to examine the surface morphology of mild steel in the presence of these inhibitors. Full article

Iron derivatives have emerged as valuable catalysts for a variety of transformations, as well as for biological and photophysical applications, and iminophosphorane can be considered an ideal ligand scaffold for modulating electronic and steric parameters in transition metal complexes. In this report, we aimed to synthesize dichloride and dibromide iron(II) complexes supported by symmetric bis(iminophosphorane)pyridine ligands, starting from readily available ferrous halides. The ease of synthesis of this class of ligands served to access several derivatives with distinct electronic and steric properties imparted by the phosphine moiety. The ligands and the resulting iron(II) complexes were characterized by ³¹P and ¹H NMR spectroscopy and DART or ESI mass spectrometry. While none of these iron(II) complexes could be characterized by single-crystal X-ray diffraction, suitable crystals of a µ-O bridged dinuclear iron complex bearing an iminophosphorane ligand were obtained, confirming a κ³ binding motif. The bis(iminophosphorane)pyridine ligands in the obtained iron(II) complexes are labile, as demonstrated by their facile substitution by terpyridine. Cyclic voltammetry studies revealed that the oxidation of bis(iminophosphorane)pyridine iron(II) complexes to iron(III) species is quasi-reversible, suggesting the strong thermodynamic stabilization of the iron(III) center imparted by the σ-donating iminophosphorane ligands. Full article

In the present study, we report the solid-state isolation and structural characterization of novel iron(III) complexes of the veterinary antibiotic monensin. Monensic acid (MonH × H₂O) forms a dinuclear complex of composition with FeCl₃ [FeCl(Mon)₂]₂ (1), while its interaction with FeSO₄ leads to the isolation of a triangular oxo-ferric coordination species [Fe₃O(Mon × H₂O)₆(H₂O)₂(OH)] (2). During the procedure resulting in 2, oxidation of the Fe(II) ions by atmospheric oxygen was observed. In the presence of organic bases, both complexation reactions proceeded to successfully deprotonate the carboxylic function of the ligand. Iron(III) complexes 1 and 2 were characterized by IR, EPR, NMR, and Mössbauer spectroscopies as well as with thermal (TG-DTA/MS) and elemental analyses. In addition, the structures of the two coordination compounds were modelled and selected calculated parameters were compared with the experimental results. The biological assay revealed the enhanced antibacterial potential of the newly obtained complexes against the Gram-positive aerobic microorganisms Bacillus cereus and Bacillus subtilis. Full article

Lead poses significant health risks to humans, including neurological and developmental impairments, particularly in children. Additionally, lead pollution in the environment can contaminate soil, water, and air, endangering wildlife and ecosystems. Therefore, this study reports the straightforward fabrication of Na₂Ca₂Si₃O₉/Ca₈Si₅O₁₈ nanostructures (NaCaSilicate) utilizing a sol-gel technique. Additionally, the produced nanostructures underwent further modification with chitosan (CS@NaCaSilicate) and chitosan crosslinked with terephthalaldehyde (CCS@NaCaSilicate), resulting in new nanocomposite materials. These samples were developed to efficiently extract Pb(II) ions from aqueous media through complexation and ion exchange mechanisms. Furthermore, the maximum adsorption capacity for Pb(II) ions by the NaCaSilicate, CS@NaCaSilicate, and CCS@NaCaSilicate samples is 185.53, 245.70, and 359.71 mg/g, respectively. The uptake of Pb(II) ions was characterized as spontaneous, exothermic, and chemical, with the best description provided by the Langmuir equilibrium isotherm and the pseudo-second-order kinetic model. Furthermore, a 9 M hydrochloric acid solution effectively eliminated Pb(II) ions from the synthesized samples, attaining a desorption efficacy surpassing 99%. Additionally, the fabricated samples exhibited efficient reusability across five successive cycles of adsorption and desorption for capturing Pb(II) ions. Full article

Two-dimensional transition metal carbides/nitrides (MXenes) are emerging members of the two-dimensional material family, obtained by removing the A layer of the MAX phase through methods such as liquid-phase etching. This article summarizes the structure and properties of MXenes, as well as several preparation methods, including etching with hydrofluoric acid and fluoride salts, alkali-based etching, electrochemical etching, Lewis acid molten salt etching, and direct synthesis. Due to their unique two-dimensional structure and surface chemistry, MXenes exhibit good metallic conductivity, hydrophilicity, excellent flexibility, and ion intercalation properties, showing great potential in the research and application of supercapacitors and attracting widespread attention. The combination of MXene with other types of materials, including polymers, metal hydroxides, metal oxides, and carbon materials, takes advantage of composites to improve energy storage performance and shows great potential in the research and application of supercapacitors. This article provides a detailed summary of MXene composite materials and capacitor performance and introduces the research progress of MXene materials in the field of supercapacitor energy storage applications, aiming to provide references for the preparation of high-performance MXene supercapacitor electrode materials. Full article

Two new metal–organic multi-component compounds of Ni(II) and Co(II), viz. [Ni(3-CNpy)₂(H₂O)₄]ADS·2.75H₂O (1) and [Co(3-CNpy)₂(H₂O)₄](4-ClbzSO₃)₂ (2) (3-CNpy = 3-cyanopyridine, ADS = anthraquinone-1,5-disulfonate, 4-ClbzSO₃ = 4-chlorobenzenesulfonate), were synthesized and characterized using single crystal XRD, TGA, spectroscopic (IR, electronic) and elemental analyses. Both the compounds crystallize as multi-component compounds of Ni(II) and Co(II), with uncoordinated ADS and 4-ClbzSO₃ moieties in the crystal lattice, respectively. Crystal structure analyses revealed the presence of antiparallel nitrile···nitrile and π-stacked assemblies involving alternate coordinated 3-CNpy and uncoordinated ADS and 4-ClbzSO₃ moieties. Moreover, unconventional charge reverse Cl∙∙∙N halogen bonding contacts observed in compound 2 provide additional reinforcement to the crystal structure. Theoretical calculations confirm that the H-bonding interactions, along with anion–π(arene) and anion–π(CN) in 1 and π–π, antiparallel CN···CN and charge reverse Cl···N halogen bonds in 2, play crucial roles in the solid state stability of the compounds. In vitro anticancer activities observed through the trypan blue cell cytotoxicity assay reveal that the compounds induce significant concentration dependent cytotoxicity in Dalton’s lymphoma (DL) cancer cells, with nominal effects in normal healthy cells. Molecular docking studies reveal that the compounds can effectively bind with the active sites of anti-apoptotic proteins, which are actively involved in cancer progression. Full article

The thermodynamic aspects of the process of inclusion complex formation between β-cyclodextrin (acting as a host) and gaseous substances (guests; N₂O, CO₂, NO₂, SO₂, HCN, CH₄, CH₃CH₂CH₃) are studied by employing well-calibrated and tested density functional theory (DFT) calculations. This study sheds new light on the intimate mechanism of the β-cyclodextrin/gas complex formation and answers several intriguing questions: how the polarity and size of the guest molecule influence the complexation thermodynamics; which process of encapsulation by the host macrocycle is more advantageous—insertion to the central cavity without hydration water displacement or guest binding accompanied by a displacement of water molecule(s); what the major factors governing the formation of the complex between β-cyclodextrin and gaseous substances are. The special role that the cluster of water molecules inside the host’s internal cavity plays in the encapsulation process is emphasized. Full article

Biodiesel represents a promising solution for sustainable energy needs, offering an eco-friendly alternative to conventional fossil fuels. In this research, we investigate the use of a catalyst derived from mussel shells to facilitate biodiesel production from Jatropha curcas oil. Our findings from X-ray Fluorescence (XRF) analysis emphasize the importance of carefully selecting calcination temperatures for mussel shell-based catalysts, with 1100 °C identified as optimal for maximizing CaO content. We identify a reaction time of 6 h as potentially optimal, with a reaction temperature of approximately 110 °C yielding the desired methyl ester composition. Notably, a methanol-to-oil ratio of 18:1 is the most favorable condition, and the optimal methyl ester composition is achieved at a calcined catalyst temperature of 900 °C. We also assess the stability of the catalyst, demonstrating its potential for reuse up to five times. Additionally, a thorough analysis of J. curcas Methyl Ester (JCME) biodiesel properties confirmed compliance with industry standards, with variations attributed to the unique characteristics of JCME. Comparing homogeneous (NaOH) and heterogeneous (CaO) catalysts highlights the potential of environmentally sourced heterogeneous catalysts to replace their homogeneous counterparts while maintaining efficiency. Our study presents a novel approach to sustainable biodiesel production, outlining optimal conditions and catalyst stability and highlighting additional benefits compared with NaOH catalysts. Therefore, utilizing mussel shell waste for catalyst synthesis can efficiently eliminate waste and produce cost-effective catalysts. Full article

A series of novel zinc-salophen (salophen = N, N′-phenylenebis(salicylimine)) complexes (Zn-1–4) with electron donor–acceptor (D–A) structure were synthesized and characterized using a triphenylamine structure as the electron donor. Zn-salophen complexes with the same substituent sites have been reported to exhibit significant CT properties. The design of the D–A structure and the increase in the number of benzene rings to increase the length of bridging groups have led to a reduction in the energy difference between charge separation singlet and triplet states, resulting in the production of reactive oxygen species (ROS) under light irradiation. The ability has been enhanced (in terms of the production of singlet oxygen (¹O₂), compared with Zn-salophen, Zn-4 is 1.58 times higher). This method has been reported to enhance the intersystem crossing process of compounds, thereby enabling them to reach a triple excited state, but the generation of ROS has not been studied. Although the enhancement is not very significant, it has expanded the medical application prospects of these types of complexes and has provided a new strategy to enhance the production of ROS. Full article

Using density functional theory (DFT), the density of states of NH₄V₃O₈ (NVO) was analyzed pre- and post-oxygen defect (O_d) formation. The findings revealed a reduced bandgap in NVO after O_d introduction, emphasizing the role of O_d in enhancing conductivity of the material, thus improving its electrochemical attributes. Through the water bath method, both NVO and its oxygen-deficient counterpart, (NH₄)₂V₁₀O₂₅·8H₂O (NVO_d), were synthesized as potential cathode materials for aqueous zinc-ion batteries (AZIBs). Experimental outcomes resonated with DFT predictions, highlighting the beneficial role of oxygen defects in boosting electrical conductivity. Notably, the refined material displayed a remarkable capacity of 479.3 mAh g⁻¹ at 0.1 A g⁻¹, underscoring its promise for advanced energy storage solutions. Full article

Ferrocene has a unique structure, i.e., a central iron atom neatly sandwiched between two cyclopentadienyl rings, which has revolutionized the chemists’ views about how metals bind to organic π-systems. This structural arrangement leads to some fascinating chemical and photophysical properties. The last three decades, there were reports about receptor molecules that could be considered to perform simple logic operations via coupling ionic bonding or more complex molecular-recognition processes with photonic (fluorescence) signals. In these systems, chemical binding (‘input’) results in a change in fluorescence intensity (‘output’) from the receptor. It has been proven that molecules respond to changes in their environment, such as the presence of various ions, neutral species, pHs, temperatures, and viscosities. Since their first realization by de Silva, molecular logic gates have been intensively experimentally studied, with purely theoretical studies being less common. Here, we present the research that has been conducted on Molecular Logic Gates (MLGs) containing ferrocene and their applications. We categorized such systems into three families of MLGs: long-chain molecules (oligomers or polymers) that incorporate ferrocene, medium-sized molecules that incorporate ferrocene, and systems where ferrocene or its derivatives are used as external additives. Furthermore, MLGs including metal cations without the ferrocene moiety are briefly presented, while computational methodologies for an accurate theoretical study of MLG, including metal cations, are suggested. Finally, future perspectives of MLGs containing ferrocene and their applications are also presented. Full article

This study demonstrates the current advancements in battery management systems (BMSs), emphasizing the need for precise temperature monitoring within battery packs to enhance safety and performance through efficient thermal management. The increased demand for lithium-ion batteries (LIBs) has driven the development of temperature sensors with improved accuracy and stability. In particular, Ni-Co-Mn-based spinel oxides are commonly used due to their stable negative temperature coefficient (NTC) behavior. However, challenges arise in manufacturing due to the high cost and uncertain supply of critical cathode components (e.g., Co, Ni, and Mn) for LIBs. This research focuses on developing spinel-type (Ni_0.6Co_0.4Mn₂)O₄ using recycled Ni-Co-Mn oxides obtained from end-of-life (EOL) LIBs, demonstrating temperature resistance behavior suitable for temperature sensing. The oxides are prepared through hydrometallurgy, oxalate synthesis, and post-heat treatment. Successful integration into spinel-type NTC thermistors suggests broader applications in various industrial fields. A systematic investigation into the synthesis and characterization of recovered Ni-Co-Mn oxides from EOL LIB cathode materials (Li(Ni_0.33Co_0.33Mn_0.33)O₂) is presented for NTC thermistor application. Thermogravimetric analysis-derivative thermogravimetry (TGA-DTG) identifies the optimal post-heat treatment temperature. The X-ray diffraction (XRD) patterns confirm a cubic spinel structure of the Ni-Co-Mn oxides, supported by scanning electron microscope (SEM) images showing a uniform microstructure. Also, energy dispersive X-ray spectroscopy (EDS) mapping confirms homogeneous element distribution. Recovered oxide pellets from the sintering process exhibit a single spinel structure, with X-ray photoelectron spectroscopy (XPS) analysis revealing changes in the valence states for Ni and Mn. Resistivity measurements demonstrate semiconductive behavior, which shows a B value (3376.92 K) suitable for NTC thermistor applications. This study contributes valuable insights to black powder recycling from EOL LIBs and its potential in temperature-sensitive electronic devices. Full article

The use of conductive polymers in aluminium electrolytic capacitors prevents leakage and enlarges the temperature use range when compared with their liquid counterparts. PEDOT:PSS is an outstanding candidate due to its tunable properties, i.e., electronic conductivity (10⁻⁵ to 10³ S/cm), and its high thermal stability. As a result of their synthesis, PEDOT:PSS dispersions are characterized by a low pH value, which can influence pH sensitive materials such as aluminium. However, no work to date has studied the interaction between PEDOT:PSS dispersions and aluminium oxide substrates. In this work, the interface and interaction between PEDOT:PSS and an aluminium electrode were studied for the first time via odd random phase electrochemical impedance spectroscopy and analysed post mortem by SEM and AFM characterization. PEDOT:PSS dispersions at different pH values (1.9, 4.9, 5.8) were applied in a layered manner onto a non-etched aluminium substrate with a grown oxide layer on top, which provided a model system for the analysis of the interface. The analysis showed that the acidic PEDOT:PSS dispersions attacked the aluminium substrate, forming pores on the surface, but had a positive impact on the capacitance of the aluminium oxide/PEDOT:PSS systems. On the other hand, neutral dispersions did not affect the aluminium electrode, but showed poor layer formation properties, and the electrochemical analysis displayed a dispersion of results ranging from capacitive to resistive behaviour. Full article

Material selection for thermoelectric modules and generators presents a considerable challenge. In commercially available thermoelectric generators, alloys with a high percentage of doping element are used to achieve different semiconductor polarity. This introduces mechanical stresses to the system due to the varying thermal expansion rates. Previous studies have demonstrated that the semiconductor polarity of SnSe alloys can be altered through Sb or Bi doping. This paper outlines a modified, scalable and cost-effective direct synthesis process for SnSe alloys, employing Sb, Bi, Ag, Ni, In and Mg as dopants. Polarity switching in the synthesized materials was observed with Bi doping, occurring in similar regions as observed with monocrystalline Sb. Additionally, In doping led to a significant increase in the Seebeck coefficient. Doping elements exhibited minimal influence on the crystal lattice of the material, with only minor shifts in lattice parameters noted. Crystallography analysis revealed a significant preferred orientation, consistent with the material’s documented propensity to form and align in layers, a characteristic observable even to the naked eye and confirmed through optical and electron microscopy. Furthermore, we have developed and thoroughly calibrated an in-house apparatus for determining the Seebeck coefficient of thermoelectric materials, based on the already published methodology, which describes a method for determining the electrical conductivity of disk- and rod-shaped samples. Full article

Bipartite entanglement is comprehensively investigated in the mononuclear molecular complex (Et₃NH)[Ni(hfac)₂L], where HL denotes 2-(2-hydroxy-3-methoxy-5-nitrophenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-3-oxide-1-oxyl and hfacH stands for hexafluoroacetylacetone. From the magnetic point of view, the molecular compound (Et₃NH)[Ni(hfac)₂L] consists of an exchange-coupled spin-1 Ni²⁺ magnetic ion and a spin-$\frac{1}{2}$ nitronyl-nitroxide radical substituted nitrophenol. The nickel-radical molecular complex affords an experimental realization of a mixed spin-($\frac{1}{2}$, 1) Heisenberg dimer with a strong antiferromagnetic exchange coupling, J/$k_B$ = 505 K, and two distinct g-factors, g_Rad = 2.005 and g_Ni = 2.275. By adopting this set of magnetic parameters, we demonstrate that the Zeeman splitting of a quantum ferrimagnetic ground-state doublet due to a weak magnetic field may substantially reinforce the strength of bipartite entanglement at low temperatures. The molecular compound (Et₃NH)[Ni(hfac)₂L] maintains sufficiently strong thermal entanglement, even at room temperature, vanishing only above 546 K. Specifically, the thermal entanglement in the nickel-radical molecular complex retains approximately 40% of the maximum value, corresponding to perfectly entangled Bell states at room temperature, which implies that this magnetic compound provides a suitable platform of a molecular qubit with potential implications for room-temperature quantum computation and quantum information processing. Full article

Iron is an essential nutrient and necessary for biological functions from DNA replication and repair to transcriptional regulation, mitochondrial respiration, electron transfer, oxygen transport, photosynthesis, enzymatic catalysis, and nitrogen fixation. However, due to iron’s propensity to generate toxic radicals which can cause damage to DNA, proteins, and lipids, multiple processes regulate the uptake and distribution of iron in living systems. Understanding how intracellular iron metabolism is optimized and how iron is utilized to regulate other intracellular processes is important to our overall understanding of a multitude of biological processes. One of the tools that the cell utilizes to regulate a multitude of functions is the ligation of the iron–sulfur (Fe-S) cluster cofactor. Fe-S clusters comprised of iron and inorganic sulfur are ancient components of living matter on earth that are integral for physiological function in all domains of life. FeS clusters that function as biological sensors have been implicated in a diverse group of life from mammals to bacteria, fungi, plants, and archaea. Here, we will explore the ways in which cells and organisms utilize Fe-S clusters to sense changes in their intracellular environment and restore equilibrium. Full article

Novel zinc-blende (zb) group-IV binary XC and ternary X_xY_1−xC alloys (X, Y ≡ Si, Ge, and Sn) have recently gained scientific and technological interest as promising alternatives to silicon for high-temperature, high-power optoelectronics, gas sensing and photovoltaic applications. Despite numerous efforts made to simulate the structural, electronic, and dynamical properties of binary materials, no vibrational and/or thermodynamic studies exist for the ternary alloys. By adopting a realistic rigid-ion-model (RIM), we have reported methodical calculations to comprehend the lattice dynamics and thermodynamic traits of both binary and ternary compounds. With appropriate interatomic force constants (IFCs) of XC at ambient pressure, the study of phonon dispersions ${\omega }_j\left(\overrightarrow{\mathit{q}}\right)$ offered positive values of acoustic modes in the entire Brillouin zone (BZ)—implying their structural stability. For X_xY_1−xC, we have used Green’s function (GF) theory in the virtual crystal approximation to calculate composition x, dependent ${\omega }_j\left(\overrightarrow{\mathit{q}}\right)$ and one phonon density of states $g\left(\omega \right)$. With no additional IFCs, the RIM GF approach has provided complete ${\omega }_j\left(\overrightarrow{\mathit{q}}\right)$ in the crystallographic directions for both optical and acoustical phonon branches. In quasi-harmonic approximation, the theory predicted thermodynamic characteristics (e.g., Debye temperature Θ_D(T) and specific heat C_v(T)) for X_xY_1−xC alloys. Unlike SiC, the GeC, SnC and Ge_xSn_1−xC materials have exhibited weak IFCs with low [high] values of Θ_D(T) [C_v(T)]. We feel that the latter materials may not be suitable as fuel-cladding layers in nuclear reactors and high-temperature applications. However, the XC and X_xY_1−xC can still be used to design multi-quantum well or superlattice-based micro-/nano devices for different strategic and civilian application needs. Full article

The endohedral lithium fulleride, Li⁺@C₆₀^•−, is a potential precursor for new families of molecular superconducting and electronic materials beyond those accessible to date from C₆₀ itself. Solid Li@C₆₀ comprises (Li@C₆₀)₂ dimers, isostructural and isoelectronic with the (C₅₉N)₂ units found in solid azafullerene. Here, we investigate the structural and vibrational properties of Li@C₆₀ samples synthesized by electrolytic reduction routes. The resulting materials are of high quality, with crystallinity far superior to that of their antecedents isolated by chemical reduction. They permit facile, unambiguous identification of both the reduced state of the fulleride units and the interball C-C bonds responsible for dimerization. However, severe orientational disorder conceals any crystal symmetry lowering due to the presence of dimers. Diffraction reveals the adoption of a hexagonal crystal structure (space group P6₃/mmc) at both low temperatures and high pressures, typically associated with close-packing of spherical monomer units. Such a situation is reminiscent of the structural behavior of the high-pressure Phase I of solid dihydrogen, H₂. Full article

Thermoelectric materials are capable of generating electrical energy in response to a temperature gradient. Non-renewable energy resources are depleting, so the development of renewable energy sources that are environmentally sustainable is essential. One potential application of these materials as an alternative energy source is in wearable electronics. Thermoelectric materials are used in common electrical devices, as well as by the military, in healthcare, and in space. As a ductile N-type semiconducting material, silver sulfide is one of the most promising materials in terms of thermoelectric potential. The properties of Ag₂S can be improved by choosing the appropriate dopants. This study investigates the methods by which the thermoelectric, mechanical, and hardness properties of Ag₂S are improved via Ge doping. The addition of Ge increases the Seebeck coefficient to a maximum of −87 μV·K⁻¹ from −1051 μV·K⁻¹ to P-type, bringing it closer to transitioning. In order to work, a thermoelectric generator requires both N- and P-type materials. By applying homojunctions made from similar materials, internal stresses caused by the varying thermal expansion rates of different materials are reduced. In order to demonstrate Ge integration, scanning electron microscopy and X-ray diffraction were applied to the sample microstructure. In addition, supplementation was used to increase the ductility and malleability of materials to make them suitable for power generation in wearable electronics. These materials showed significant power factor values according to room-temperature measurements. This proves that materials capable of generating usable voltage lie in the recommended ambient temperature range for the user’s body, thus rendering them potential candidates for wearable electronics. Full article

Quantum yield illustrates the efficiency that a fluorophore converts the excitation light into fluorescence emission. The quantum yield of carbon quantum dots (CQDs) can be altered via precursors, fabrication conditions, chemical doping, and surface modifications. In this study, CQDs were first fabricated from whole-meal bread using a chemical-free hydrothermal route, and a low quantum yield (0.81%) was obtained. The combination of whole-meal bread, soybean flour, and lemon juice generated CQDs with almost four folds of enhancement in quantum yield. Detailed characterization suggested that these CQDs were subjected to more complete hydrothermal reactions and had zwitterionic surfaces. The CQDs could selectively detect Cr (VI) ions with a limit of detection (LOD) of 8 ppm. This study shows that the enhancement of the quantum yield of CQDs does not need chemicals, and it is achievable with food precursors. Full article