Inorganics, Volume 11, Issue 4 (April 2023) – 41 articles

Ru-ZnO-g-C₃N₄ nanocomposite was made using a straightforward ultrasonication method and evaluated for its potential to remove Cd ions from aqueous environments. X-ray diffraction analysis confirms composite production with an average crystalline size of 6.61 nm, while transmission electron microscopy results indicate nanosheet-like nanomaterials with uniform elements distribution. Measurements of N2 adsorption–desorption reveal the creation of a mesoporous structure with a BET surface area of approximately 257 m²/g. Fourier converted infrared reveals vibrational modes for O-H, amino groups, triazine, and Ru-ZnO. In contrast, X-ray photoelectron spectroscopy investigation reveals the presence of the elements Ru, Zn, O, N, and C. Ru-ZnO-g-C₃N₄ nanocomposite has remarkable adsorption efficiency for aqueous Cd ions, achieving 475.5 mg/g in 18 min. This study reveals that the Ru-ZnO-g-C₃N₄ nanocomposite may be used as an effective and reusable adsorbent for removing Cd ions during wastewater treatment and, possibly, for eliminating other toxic metal ions. Full article

The investigation of the interaction of cyclic trinuclear silver(I) pyrazolate [AgPz]₃ (Pz = 3,5-bis(trifluoromethyl)pyrazolate) with pyridine-based chalcones (anthracen-9-yl and phenyl-substituted ones) has been performed by IR-, UV-vis, and NMR spectroscopies in the solution. The carbonyl group participates in coordination with metal ions in all complexes. However, the network of π-π/M-π non-covalent intermolecular interactions mainly influences complex formation. The spectral data suggest retaining the structures for all studied complexes in the solution and solid state. E-Z isomerization in the case of anthracene-containing compounds significantly influences the complexation. E-isomer of chalcones seeks the planar structure in the complexes with [AgPz]₃. In contrast, the Z-isomer of chalcone demonstrates the chelating coordination of O- and N atoms to silver ions. The complexation of anthracene-containing chalcones allows the switching of the emission nature from charge transfer to ligand-centered at 77 K. In contrast, phenyl-substituted chalcone in complex with macrocycle demonstrates that the emission significantly shifted (Δ = ca. 155 nm) to the low-energy region compared to the free base. Full article

Ni(II), Pd(II), and Pt(II) complexes [M(Y-terpy)X] (X = Cl or Br) containing the tridentate N^C^N-cyclometalating 2,3′:5′,2″and 2,2′:4′,2″ stereoisomers of the well-known tridentate N^N^N ligand 2,2′:6′,2″-terpyridine (terpy) were synthesised in moderate to good yields through C–H activation. For the Pt complexes, the phenyl ethynide derivatives [Pt(Y-terpy)(C≡CPh)] were also obtained under Sonogashira conditions. In contrast to this, C^N^N cyclometalated complexes using the 2,2′:6′,3″- and 2,2′:6′4″-terpy isomers were not obtained. Comparison of the N^C^N complexes of the cyclometalated 2,3′:5′,2″- and 2,2′:4′,2″-terpy ligands with complexes [M(dpb)Cl] of the prototypical N^C^N cyclometalating ligand dpb⁻ (Hdpb = 2,6-diphenyl-pyridine) showed higher potentials for the terpy complexes for the ligand-centred reductions in line with the superior π-accepting properties of the terpy ligands compared with dpb. Metal-centred oxidations were facilitated by the dpb ligand carrying a central σ-donating phenyl group instead of a metalated pyridine moiety. The same trends were found for the long-wavelength absorptions and the derived electrochemical and optical band gaps. The lower σ-donating capacities of the cyclometalated terpy derivatives is also confirmed by a reduced trans influence in the structure of [Ni(2,3′:5′,2″-terpy)Br_0.14/OAc_0.86]. Attempts to re-crystallise some poorly soluble Pd(II) and Pt(II) complexes of this series under solvothermal conditions (HOAc) gave two structures with N-protonated cyclometalated pyridine moieties, [Pt(2,3′:5′,2″-terpyH)Cl]^.Cl and [Pd(2,3′:5′,2″-terpyH)Cl₂]. Full article

Understanding and regulating DNA interactions with solvents and redox-active centers opens up new possibilities for improving electrochemical signals and developing adequate biosensors. This work reports the development of a modified indium tin oxide (ITO) electrode by chemical vapor deposition (CVD) of graphene for the detection of double-stranded DNA. The modified electrode shows a better electrical conductivity than ITO, as confirmed by electrochemical impedance spectroscopy (EIS), where a drastic decrease in the charge–transfer resistance, R_ct, from ~320 to ~60 Ω was observed. Sequences of double-stranded genomic DNA with a different number of base pairs are evaluated through differential pulse voltammetry (DPV), using ferri/ferrocyanide ([Fe(CN)₆]^3−/4−) as a mediator in the solution. Variations in the electrochemical response of the [Fe(CN)₆]^3−/4− probe are observed after introducing redox inactive double-stranded DNA ions. The redox-active [Fe(CN)₆]^3−/4− probe serves as a scaffold to bring DNA into the graphene-modified ITO electrode surface, provoking an increase in the current and a change in the potential when the number of base pairs increases. These results are confirmed by EIS, which shows a variation in the R_ct. The calibration of DPV intensity and R_ct vs. DNA base pairs (bps) number were linear in the 495–607 bps range. The proposed method could replace the nucleic acid gel electrophoresis technique to determine the presence of a DNA fragment and quantify its size. Full article

The correlation of the electrocatalytic activity with electrical conductivity, oxygen-vacancies, and electronegativity have been studied in a series of isostructural oxides, having the so-called Ruddlesden-Popper structure. The structures of these materials comprise transition metals that are octahedrally coordinated to form a network of bilayer stacks. These materials are catalytically active for both half-reactions of water-splitting, namely oxygen-evolution reaction (OER) and hydrogen-evolution reaction (HER). They show a systematic increase in electrocatalytic activity in progression from Sr₃Ti₂O₇ to Sr₃TiMnO₇, Sr₃TiFeO_7−δ, and Sr₃TiCoO_7−δ. The kinetic studies using the Tafel method indicate the same trend across the series, where the best catalyst also has the fastest kinetics for both HER and OER. In addition, the same progression is observed in the concentration of oxygen-vacancies, as well as the electrical conductivity in a wide range of temperatures, 25 °C–800 °C. The material that shows the best electrocatalytic activity, i.e., Sr₃TiCoO_7−δ, also has the highest electrical conductivity and the greatest concentration of oxygen vacancies in the series. The correlations observed in this work indicate that trends in electrocatalytic performance may be related to the systematic increase in electrical conductivity, electronegativity, and oxygen-vacancies, as well as the electron occupancy of e_g orbitals, which can affect the strength of sigma interactions between the catalyst and reaction intermediates. Full article

A complex processing variant for pyrite cinders, i.e., the technogenic waste generated in the production of sulfuric acid, was proposed. This method provided preliminary chemical activation of the initial raw materials that comprised thermal treatment with a sodium bicarbonate solution and resulted in structural and phase changes of separate minerals. Due to chemical activation, it was possible to separate the nonferrous metals into separate products (in addition to the partial extraction of iron) and then concentrate the noble metals in the residue. The noble metals were then able to be extracted through a leaching process with a complex reagent based on sulfur compounds and subsequent cementation with zinc dust. The developed method, unlike pyrometallurgical methods, is less energy-consuming and more easily implemented than the known hydrometallurgical variants, enabling the separation of nonferrous metals and the partial separation of iron into separate middlings at the first stage. Noble metals are concentrated in the residue and extracted from it. Full article

Achieving high−efficiency and stable hydrogen evolution from water splitting is a great challenge. Herein, a facilely prepared two−dimenssional self−supported catalytic electrode with excellent stability is constructed for large−scale hydrogen production from alkaline simulated seawater. The bifunctional catalytic electrode is prepared by a fast and mild one−step of sodium borohydride etching on a nickel foam (NF) substrate without adding other additives ([email protected]_x−3h). The overpotential of the hydrogen/oxygen evolution reaction (HER/OER) in alkaline−simulated seawater at 10 mA cm⁻² is 96 mV and 261 mV. At 200 mA cm⁻², the [email protected]_x−3h electrode shows good stability over 7 days throughout the water splitting process due to the corrosion resistance of the NF substrate, and strong adhesion between the Ni−B active material and the substrate. This work demonstrates a novel strategy for fabricating catalytic electrodes with high−performance, low cost and excellent stability. Full article

With the flourishing development of the new energy automobile industry, developing novel electrode materials to balance the capacity between cathode and anode is a challenge for hybrid supercapacitors. In comparison to conventional inorganic materials, metal–organic frameworks materials offer higher porosity and greater surface area for use in supercapacitors. Herein, we proposed a facile one–pot solvothermal technique to synthesize an Fe(BPDC) nanosheet array on Ni foam, which we then applied as a binder–free cathode for a supercapacitor. The solvothermal time was adjusted to ensure a desirable morphology of the final product. Benefitting from the impressive nanosheet morphology, to a great extent, Fe(BPDC) has solved the problem of volume expansion of Fe–based electrode materials during cycling, and exhibits brilliant electrochemical performances, i.e., high specific capacitance (17.54 F/cm² at 1 mV/s) and satisfactory cycle performance (129% retention after 10,000 cycles). Furthermore, Fe(BPDC) and activated carbon (AC) have been chosen to assemble a hybrid supercapacitor (namely Fe(BPDC)//AC), delivering an energy density of 45.64 Wh/kg at the power density of 4919.6 W/kg with 87.05% capacitance retention after 10,000 cycles. These brilliant results prove that Fe(BPDC) material has great potential as the cathode of supercapacitors. Full article

Organic-inorganic hybrid perovskites are highly efficient in photovoltaic applications, making the commercialization of perovskite solar cells (PSCs) possible. However, the high density of defects on the surface significantly affects the performance of PSCs. To address this issue, we have demonstrated a facile post-treatment strategy utilizing methylhydrazine iodide (MHyI) to passivate the surface of the perovskite film. MHyI could co-ordinate with the dangling bonds on the surface of perovskite films, effectively passivating defects in the film and suppressing carrier non-radiative recombination. As a result, PSCs with MHyI modification exhibit a champion power conversion efficiency (PCE) of 23.19% and a high open-circuit voltage (V_OC) of 1.14 V (0.43 V voltage deficit). Moreover, unencapsulated solar cells maintain their initial efficiency of 88% after 30 days of exposure to ambient air with 30% humidity, and the devices with encapsulation retained 57% of their initial efficiency after 200 h of maximum power point (MPP) loading under constant light irradiation in ambient air. Overall, our results provide a facile method for improving the performance and stability of PSCs. Full article

Four new Ni^II, Co^II, Zn^II, and Cu^II complexes with the promising anti-tuberculosis drug (E/Z)-N′-((5-Hydroxy-3,4-bis(hydroxymethyl)-6-methylpyridin-2-yl)methylene)-isonicotino-hydrazide (LH) were synthesized and characterized by structural methods: single-crystal X-ray diffraction, vibrational spectroscopy, and mass spectrometry. The Ni^II, Co^II, and Zn^II metal ions form only amorphous phases with various morphologies according to mass spectrometry and IR spectroscopy. The Cu^II forms a crystalline 1D coordination polymer with the relative formula $\left\{\left[\mathrm{Cu}L\mathrm{Cl}\right]·0.5{\mathrm{H}}_2\mathrm{O}\right\}_{\infty }^1$. Even though the LH ligand in the crystalline state includes a mixture of E-/Z-isomers, only the tautomeric iminol E-/Z-form is coordinated by Cu^II in the crystal. The copper(II) complex crystallizes in the monoclinic P2₁/n space group with the corresponding cell parameters a = 16.3539(11) Å, b = 12.2647(6) Å, and c = 17.4916(10) Å; α = 90°, β = 108.431(7)°, and γ = 90°. DFT calculations showed that the Z-isomer of the LH ligand in solution has the lowest formation energy due to intramolecular hydrogen bonds. According to the quantum chemical calculations, the coordination environment of the Cu^II atom during the transfer of the molecule into the solution remains the same as in the crystal, except for the polymeric bond, namely, distorted trigonal bipyramidal. Some of the complexes investigated can be used as effective sensors in biosystems. Full article

Environmental deterioration has put higher requirements on the acid resistance of automotive glass enamel. The present paper aims to prepare acid-resistant glass-ceramics used in automobile glass enamel. Base glasses with the compositions 15R₂O-xBi₂O₃-10B₂O₃-(75-x) SiO₂ (R₂O is a mixture of Li₂O, Na₂O, and K₂O (1:1:1, molar ratio), where x = 10, 15, 20, 25, and 30, respectively) was prepared by the melt-quenching method, and glass-ceramics were prepared by their controlling crystallization heat treatment. Crystallization behavior and crystallization ability of base glasses were investigated using the thermal stability parameter (S), the crystallization kinetics calculation results of base glasses, as well as the phase identification results of the heat-treated samples. The effects of the heat treatment temperature on the micromorphology and acid resistance of the heat-treated glasses were also investigated. Then, the optimized glass ceramic was used to prepare automotive glass enamel. The results indicate that: (I) with the increase of Bi₂O₃/SiO₂ ratio, the characteristic temperature of the base glass decreases, the coefficient of thermal expansion (CTE) and crystallization ability increases significantly, the crystallization temperature range becomes wider; (II) the crystallization activation energy of base glasses are in the range of 169~264 kJ/mol; (III) Bi₂SiO₅ and Bi₂O₂SiO₃ metastable phases are mainly precipitated when the crystallization temperature is between 530 °C and 650 °C, while only Bi₄Si₃O₁₂ phase is precipitated when the crystallization temperature is above 650 °C; (IV) crystallinity of base glass increases significantly with increasing heat treatment temperature, which is beneficial to improve the acid resistance of heat treated products; (V) automotive glass enamel was prepared by mixing 15R₂O-25Bi₂O₃-10B₂O₃-50SiO₂ glass-ceramic powder with copper-chrome black and varnish, and then printed on the automobile glass substrate. All the properties of the sintered enamel can meet the market requirements, and the acid resistance of our product is better than that of market products. Full article

It has been demonstrated that different organoboron compounds interact with some well-known molecular targets, including serine proteases, transcription factors, receptors, and other important molecules. Several approaches to finding the possible beneficial effects of boronic compounds include various in silico tools. This work aimed to find the most probable targets for five aromatic boronic acid derivatives. In silico servers, SuperPred, PASS-Targets, and Polypharmacology browser 2 (PPB2) suggested that the analyzed compounds have anticancer properties. Based on these results, the antiproliferative effect was evaluated using an in vitro model of triple-negative breast cancer (4T1 cells in culture). It was demonstrated that phenanthren-9-yl boronic acid and 6-hydroxynaphthalen-2-yl boronic acid have cytotoxic properties at sub-micromolar concentrations. In conclusion, using in silico approaches and in vitro analysis, we found two boronic acid derivatives with potential anticancer activity. Full article

A tridentate bis-NHC Pd complex, based on caffeine, was studied for its catalytic activity. This complex displayed a high catalytic activity in the Suzuki–Miyaura and Mizoroki–Heck cross-coupling reactions of aryl halides. The Sonogashira cross-coupling was also investigated but reveals a fast plateauing of the reaction. Aryl iodides as well as aryl bromides react when equipped with either electron-donating or electron-withdrawing substituents. Aryl chlorides, which contained electron-withdrawing groups, were also reactive under the applied conditions. Full article

This study aims to prepare a supported catalyst based on zeolite Y doped with NaOMe (sodium methoxide) for the transesterification of waste cooking oil (WCO). The catalytic screening data showed that NaOMe/zeolite is a prominent catalyst for the transesterification of WCO prepared by a solvent-free, ball-milling process. We initially tested 5–20% of sodium methoxide loading onto zeolite Y and found that 20% is the optimum loading for the reaction. The transesterification reaction required a comparatively lower methanol-to-oil mole ratio of 16:1 with the reaction temperature as 60 °C. The ball-milled NaOMe/zeolite catalyst was characterized by BET surface area analysis, FE-SEM, TEM, FT–IR, and XRD. The BET surface analysis revealed that the surface area for zeolite Y was substantially decreased in the NaOMe/zeolite catalyst. The ball-milling process dropped the crystallinity of zeolite Y, which can be seen from the XRD and FE-SEM images of both zeolite Y and the NaOMe/zeolite catalyst. Finally, the transesterification reaction product was fully characterized by ${}^1$H-NMR and viscosity analysis for biodiesel, glycerol, and the WCO. The chemical shifts for the biodiesel and glycerol are found accordingly. This is also supported by the FT–IR characterization of biodiesel, glycerol, and WCO. It is noteworthy that a very high mass ratio of 250 g oil/g NaOMe is obtained when converting WCO to biodiesel, indicating very high catalytic activity for the aforementioned catalyst. Full article

Keggin heteropolyacids (HPAs) are metal–oxygen clusters with strong Bronsted acidity. The conversion of HPAs to metal salts can result in Lewis acidity, improving their performance in oxidation reactions. In this review, the main routes for the synthesis of Keggin-type heteropolyacids salts, as well their use as catalysts in oxidation processes of a plethora of substrates, such as monoterpenes, olefins, aldehydes, terpene alcohols, and aromatics, are described. Green reactants such as hydrogen peroxide and molecular oxygen are used as oxidants. These reactions are of interest to several industries because they can be used to produce drugs, additives, fragrances, and fine chemicals. The high efficiency of Keggin HPA with green oxidants contributes to a reduction in the environmental impact of these processes, as preconize the principles of green chemistry. Moreover, Keggin HPAs can be converted to bifunctional catalysts by the modification of their structure, total or partial replacement of their protons with Lewis acid metal cations, or the introduction of these cations into the Keggin anion structure, replacing the addenda atoms (i.e., W and Mo). Aspects linked to the synthesis and characterization of these catalysts are discussed herein, with emphasis on infrared spectroscopy and powder XRD patterns. The most recent advances achieved in the development of catalytic oxidation systems based on Keggin HPA salts are also addressed. Full article

The oxygen evolution reaction (OER) is a crucial half-reaction in water splitting. However, this reaction is kinetically sluggish owing to the four-electron (4 e⁻) transfer process. Therefore, the development of low-cost, stable, highly efficient, and earth-abundant electrocatalysts for the OER is highly desirable. Metal oxides derived from metal–organic frameworks (MOFs) are among the most efficient electrocatalysts for the OER. Herein, Ce–MOF-derived CeO₂/graphene oxide (GO) composites were successfully prepared using a facile method. The composites with 0, 25, 50, and 100 mg GO were named CeO₂, CeO₂–GO-1, CeO₂–GO-2, and CeO₂–GO-3, respectively. The physicochemical characteristics of the electrocatalysts were assessed using several analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET) analysis. The TEM results revealed that the CeO₂ had a sheet-like morphology and that a GO layer was noticeable in the synthesized CeO₂–GO-3 composite. The characterization results confirmed the formation of impurity-free CeO₂–GO composites. The OER activity and stability were measured using cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). The CeO₂–GO-3 electrocatalyst has a smaller Tafel slope (176 mV·dec⁻¹) and lower overpotential (240 mV) than the other electrocatalysts. In addition, it exhibited high cyclic stability for up to 10 h. Therefore, the inexpensive CeO₂–GO-3 electrocatalyst is a promising OER candidate. Full article

Yttrium-doped barium zirconate is one of the fastest solid-state proton conductors. While previous studies suggest that proton–tuples move as pairs in yttrium-doped barium zirconate, a systematic catalog of possible close proton–tuple moves is missing. Such a catalog is essential to simulating dual proton conduction effects. Density functional theory with the Perdew–Burke–Ernzerhof functional is utilized to obtain the total electronic energy for each proton–tuple. The conjugate gradient and nudged elastic band methods are used to find the minima and transition states for proton–tuple motion. In the lowest-energy configuration, protons are in close proximity to each other and the dopant, significantly affecting the backbone structure. The map of moves away from the global minimum proton–tuple shows that the most critical move for long-range proton conduction is a rotation with a barrier range of 0.31–0.41 eV when the two protons are in close proximity. Full article

Sb₂(S, Se)₃ solar cells have shown great promise due to the advantages of low cost, non-toxic and high stability. However, traditional devices commonly use noble metal as the back electrode, which not only increases device cost but also limits device stability. Herein, carbon materials are used to replace the noble metals in Sb₂(S, Se)₃ solar cells. In addition, to grow high-quality Sb₂(S, Se)₃ films, a two-step hydrothermal method was developed. The carbon-based Sb₂(S, Se)₃ solar cells based on the above film achieved a power conversion efficiency (PCE) of 2.76%. After inserting a stable P3HT layer at the Sb₂(S, Se)₃ film/carbon interface, hole extraction was enhanced and the PCE was promoted to 4.15%. This work brings out a promising route to produce emerging solar cells with cost-effective and stable materials. Full article

This review presents an analysis of different algorithms for predicting the sensory ability of organic compounds towards metal ions based on their chemical formula. A database of chemosensors containing information on various classes of suitable compounds, including dipyrromethenes, BODIPY, Schiff bases, hydrazones, fluorescein, rhodamine, phenanthroline, coumarin, naphthalimide derivatives, and others (a total of 965 molecules) has been compiled. Additionally, a freely available software has been developed for predicting the sensing ability of chemical compounds, which can be accessed through a Telegram bot. This tool aims to assist researchers in their search for new chemosensors. Full article

The rapid development of technological processes in various industrial fields has led to surface water pollution with different organic pollutants, such as dyes, pesticides, and antibiotics. In this context, it is necessary to find modern, environmentally friendly solutions to avoid the hazardous effects on the aquatic environment. The aim of this paper is to improve the photocatalytic performance of zinc oxide (ZnO) nanoparticles by using the plasmonic resonance induced by covering them with gold (Au) nanoparticles. Therefore, we evaluate the charge carriers’ behavior in terms of optical properties and reactive oxygen species (ROS) generation. The ZnO-Au nanocomposites were synthesized through a simple chemical protocol in multiple steps. ZnO nanoparticles (NPs) approximately 20 nm in diameter were prepared by chemical precipitation. ZnO-Au nanocomposites were obtained by decorating the ZnO NPs with Au at different molar ratios through a reduction process. X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) confirmed the simultaneous presence of hexagonal ZnO and cubic Au phases. The optical investigations evidenced the existence of a band-gap absorption peak of ZnO at 372 nm, as well as a surface plasmonic band of Au nanoparticles at 573 nm. The photocatalytic tests indicated increased photocatalytic degradation of the Rhodamine B (RhB) and oxytetracycline (OTC) pollutants under visible light irradiation in the presence of ZnO-Au nanocomposites (60–85%) compared to ZnO NPs (43%). This behavior can be assigned to the plasmonic resonance and the synergetic effects of the individual constituents in the composite nanostructures. The spin-trapping experiments showed the production of ROS while the nanostructures were in contact with the pollutants. This study introduces new strategies to adjust the efficiency of photocatalytic devices by the combination of two types of nanostructures with synergistic functionalities into one single entity. ZnO-Au nanocomposites can be used as stable photocatalysts with excellent reusability and possible industrial applications. Full article

The current research is about the synthesis of pure nickel sulfide, a series of Te (0, 0.5, 1, 1.5, 2, and 3 wt.%)-doped NiS ([email protected]) nanoparticles (NPs), and a series of S-g-C₃N₄ (10, 30, 50, 70, and 80 wt.%)/[email protected] nanocomposites (NCs), fabricated through a hydrothermal route. XRD and FTIR spectroscopic techniques demonstrated the successful synthesis of NPs and NCs. SEM-EDX images confirmed the flakelike structure and elemental constituents of the fabricated materials. Tauc plots were drawn, to calculate the band gaps of the synthesized samples. Te doping resulted in a significant reduction in the band gap of the NiS NPs. The photocatalytic efficiency of the NPs and NCs was investigated against MB, under sunlight. The results obtained for the photocatalytic activity, showed that 1%[email protected] nanoparticles have an excellent dye degradation capacity in sunlight. This was made even better by making a series of SGCN/1% [email protected] nanocomposites with different amounts of S-g-C₃N₄. When compared to NiS, [email protected], SGCN, and 70%SGCN/1%[email protected], the 70%SGCN/1%[email protected] NCs have excellent antifungal ability. The higher impact of SGCN/[email protected], may be due to its enhanced ability to disperse and interact with the membranes and intracellular proteins of fungi. The 70%SGCN/1%[email protected] NCs showed excellent antibacterial and photocatalytic efficiency. Thus, the 70%SGCN/1%[email protected] NCs might prove fruitful in antibacterial and photocatalytic applications. Full article

High photoelectrochemical water oxidation efficiency can be achieved through an efficient photogenerated holes transfer pathway. Constructing a photoanode semiconductor heterojunction with close interface contact is an effective tactic to improve the efficiency of photogenerated carrier separation. Here, we reported a novel photoanode p-n junction of Ti:Fe₂O₃/Cu₂O (n-Ti:Fe₂O₃ and p-Cu₂O), Cu₂O being obtained by in situ reduction in CuAl-LDH (layered double hydroxides). The Ti:Fe₂O₃/Cu₂O photoanode exhibits a high photocurrent density reaching 1.35 mA/cm² at 1.23 V vs. RHE is about 1.67 and 50 times higher than the Ti:Fe₂O₃ and α-Fe₂O₃ photoanode, respectively. The enhanced PEC activity for the n-Ti:Fe₂O₃/p-Cu₂O photoelectrode is due to the remarkable surface charge separation efficiency (η_surface 85%) and bulk charge separation efficiency (η_bulk 72%) formed by the p-n junction and the tight interface contact formed by in situ reduction. Moreover, as a cocatalyst, CuAl-LDH can protect the Ti:Fe₂O₃/Cu₂O photoanode and improve its stability to a certain extent. This study provides insight into the manufacturing potential of in situ reduction layered double hydroxides semiconductor for designing highly active photoanodes in the field of photoelectrochemical water oxidation. Full article

Green zinc-metal-pillared bentonite mediated curcumin extract ([email protected]/BE) was synthesized and characterized as a low-cost and multifunctional (curcumin-based phytochemicals, zinc-capped curcumin, zinc/curcumin complexes, and zinc-pillared bentonite) antioxidant and antidiabetic agent with enhanced activity. The activities of the [email protected]/BE structure were assessed in comparison with curcumin and ZnO as individual components and in the presence of miglitol and acarbose commercial drugs as controls. The structure validated remarkable antioxidant activities against the common oxidizing radicals (nitric oxide (94.7 ± 1.83%), DPPH (96.4 ± 1.63%), ABTS (92.8 ± 1.33%), and superoxide (62.3 ± 1.63 %)) and inhibition activities against the main oxidizing enzymes (porcine α-amylase (89.3 ± 1.13%), murine α-amylase (70.8 ± 1.54%), pancreatic α-Glucosidase (99.3 ± 1.23%), intestinal α-Glucosidase (97.7 ± 1.24%), and amyloglucosidase (98.4 ± 1.64%)). The reported activities are higher than the activities of individual components and the studied ascorbic acid as well as the commercial drugs. This enhancement effect was assigned to the impact of the zinc pillaring process within the curcumin/bentonite host, which induced the stability, dispersions, and interactive interface of the essential active compounds in addition to the solubility and release rate of the intercalated curcumin extract. This paper recommends the application of the [email protected]/BE structure as an enhanced, low-cost, biocompatible, safe, and simply produced antioxidant and antidiabetic agent. Full article

Perovskite solar cells (PSCs) with p-i-n architecture attracted particular attention from the research community due to their simple and scalable fabrication at low temperatures. However, the operational stability of p-i-n PSCs has to be improved, which requires the development of advanced charge transport interlayers. Fullerene derivatives such as phenyl-C₆₁-butyric acid methyl ester (PC₆₁BM) are commonly used as electron transport layer (ETL) materials in PSCs, though they strongly compromise the device stability. Indeed, it has been shown that PC₆₁BM films actively absorb volatile products resulting from photodegradation of lead halide perovskites and transport them towards top metal electrode. Thus, there is an urgent need for development of new fullerene-based electron transport materials with improved properties, in particular the ability to heal defects on the perovskite films surface and block the diffusion of volatile perovskite photodegradation products. To address this challenge, a systematic variation of organic addends structure should be performed in order to tailor the properties of fullerene derivatives. Herein, we rationally designed a series of fullerene derivatives with different side chains and explored their performance as ETL materials in perovskite solar cells. It has been shown that among all studied compounds, a methanofullerene with thiophene pendant group enables both high efficiency and improved device operational stability. The obtained results suggest that further engineering of fullerene-based materials could pave a way for the development of advanced ETL materials enabling long lifetimes of p-i-n perovskite solar cells. Full article

Coordination complexes (1–4) of 2-amino-4-methylbenzothiazole and 2-amino-3-methylpyridine with Cu(CH₃COO)₂ and AgNO₃ were prepared and characterized by UV/Vis and FT-IR spectroscopy. The molecular structure for single crystals of silver complexes (2 and 4) were determined by X-ray diffraction. The coordination complex (2) is monoclinic with space group P21/c, wherein two ligands are coordinated to a metal ion, affording distorted trigonal geometry around the central Ag metal ion. The efficient nucleophilic center, i.e., the endocyclic nitrogen of the organic ligand, binds to the silver metal. Ligands are coordinated to adopt cis arrangement, predominantly due to steric reasons. The O(2) and O(3) atoms of the $N{O}_3^{-}$ group further play an important role in such type of ligand arrangement by hydrogen bonding with the NH₂ group of ligands. Complex (4) is orthorhombic, P212121, comprising two molecules of 2-amino-3-methylpyridine as ligand coordinated with the metal ion, affording a polymeric structure. The coordination behavior of the ligand is identical to that in complex 2, wherein ring nitrogen is coordinated to the metal center and bridged to another metal ion through an NH₂ group. The resulting product is polymeric in nature with the Ag metal in the backbone and ligand as the bridge. Compounds (2–4) were found to be luminescent, while 1 did not show such activity. All compounds were screened for their preliminary biological activities such as antibacterial, antioxidant and enzyme inhibition. Compounds exhibited moderate activity in these tests. Full article

This paper reports on the influence of sintering additives CuO and MgO on the recently developed lead-free electrocaloric (EC) material Ba_0.82Sr_0.18Sn_0.065Ti_0.935O₃ (BSSnT-18-6.5). Details on the sintering behavior and the resulting microstructure of bulk ceramic samples prepared through solid-state synthesis and their dielectric, ferroelectric, and electrocaloric properties are presented. On the one hand, the addition of CuO (x_CuO = 2%) significantly reduced the sintering temperature from 1400 °C to 1150 °C. On the other hand, the addition of MgO (x_MgO = 1%) dramatically reduced the average grain size from 40 µm to 0.4 µm, leading to an increase in dielectric breakdown strength from 4.4 V µm⁻¹ to 7.7 V µm⁻¹. Thus, BSSnT-18-6.5 with the addition of MgO to bulk ceramic samples could achieve maximum EC temperature changes (|ΔT_EC|) of 0.27 K around 30 °C with almost no aberration within a broad temperature range from 5 °C to 50 °C under an applied electric field change of 5 V µm⁻¹. The results show the potential of this material for the fabrication of multilayer ceramic (MLC) components for future electrocaloric applications. Full article

The effect of support on the performance of Pd₁Ag₁₀/Al₂O₃ and Pd₁Ag₁₀/CeO₂–ZrO₂ catalysts in the selective hydrogenation of diphenylacetylene (DPA) was studied. Characterization of the catalyst by DRIFTS-CO and HRTEM revealed the formation of a PdAg single-atom alloy (SAA) structure on the surface of PdAg nanoparticles, with Pd₁ sites isolated by Ag atoms. It was found that the use of CeO₂–ZrO₂ as a carrier makes it possible to increase the activity of the Pd₁Ag₁₀ catalyst by a factor of three without loss of selectivity compared to the reference Pd₁Ag₁₀/Al₂O₃. According to the HRTEM data, this catalytic behavior can be explained by an increase in the dispersion of Pd₁Ag₁₀/CeO₂–ZrO₂ compared to its Pd₁Ag₁₀/Al₂O₃ counterpart. As evidenced by DRIFTS-CO data, the high selectivity of the Pd₁Ag₁₀/CeO₂–ZrO₂ sample presumably stems from the stability of the structure of isolated Pd₁ sites on the surface of SAA Pd₁Ag₁₀/CeO₂–ZrO₂. Full article

Thiocarbohydrazone-based catalysts feature ligands that are potentially electrochemically active. From the synthesis point of view, these ligands can be easily tailored, opening multiple strategies for optimization, such as using different substituent groups or metal substitution. In this work, we show the possibility of a new strategy, involving the nuclearity of the system, meaning the number of metal centers. We report the synthesis and characterization of a trinuclear nickel-thiocarbohydrazone complex displaying an improved turnover rate compared with its mononuclear counterpart. We use DFT calculations to show that the mechanism involved is metal-centered, unlike the metal-assisted ligand-centered mechanism found in the mononuclear complex. Finally, we show that two possible mechanisms can be assigned to this catalyst, both involving an initial double reduction of the system. Full article

The application of organic electrode materials can make the whole cycle of the lithium battery operation effective for green sustainability. However, poor electronic conductivity and strong solubility in nonprotonic electrolytes limit the application of organic anodes. Here, a novel organic anode material, TP-Ni, was fabricated through the simple chelation of tea polyphenols with nickel ions. Benefiting from coordination bonds that alter the intrinsic microstructure of TPs and contribute to pseudocapacitive charging, the TP-Ni anode exhibits remarkable electrochemical properties, including a high specific capacity (1163 mAh g⁻¹ at 0.1 A g⁻¹), superb rate capability, and extraordinary cycling stability (5.0 A g⁻¹ over 4000 cycles with a capacity retention of 87.8%). This work can provide guidance for the design and synthesis of new high-performance organic electrode materials in the future and help accelerate the process of organic electrode material applications. Full article

Photoelectrochemical (PEC) water splitting is an eco-friendly method for producing clean and sustainable hydrogen fuels. Compared with the fabrication of solar hydrogen using n-type metal oxide semiconductor photoanodes, that of solar hydrogen using p-type metal oxide semiconductor photocathodes has not been researched as thoroughly. Therefore, this study investigated the effect of drop casting time on the PEC performance of a prepared CuBi₂O₄ photocathode. XPS, HRTEM, UV-DRS, Raman spectroscopy, XRD, and SEM analyses were used to characterize the prepared CuBi₂O₄ photocathode. Owing to the high charge separation and transfer, the photocurrent density of the CuBi₂O₄ photocathode was ~0.6 mA cm⁻² at 0.3 V vs. RHE. The nanoporous CuBi₂O₄ photocathode exhibited a high photocurrent density of up to 1.2 mA cm⁻² at 0.3 V vs. RHE with H₂O₂ as a sacrificial agent. Mott–Schottky and impedance measurements were also performed on the CuBi₂O₄ photocathode to estimate its acceptor density and charge-transfer resistance. Full article