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Synthesis of non-toxic cobalt-benzimidazole metal–organic framework decorated reduced graphene oxide composite for asymmetric supercapacitor applications.

Synthesis of LaCoO3@CNF composite as an electrocatalyst enables electrochemical detection of vanillin in food samples.

Synthesis of magnetic strontium hexaferrite particles by a chemical co-precipitation method for asymmetric supercapacitor applications.

Further development of solid oxide fuel cell (SOFC) oxygen electrodes can be achieved through improvements in oxygen electrode design by microstructure miniaturization alongside nanomaterial implementation. In this work, improved electrochemical performance of an La

Nanomaterials have versatile properties owing to their high surface-to-volume ratio and can thus be used in a variety of applications. This work focused on applying a facile hydrothermal strategy to prepare praseodymium vanadate nanoparticles due to the importance of nanoparticles in today's society and the fact that their synthesis might be a challenging endeavor. The structural and morphological characterizations were carried out to confirm the influence of the optimizations on the reaction's outcomes, which revealed praseodymium vanadate (PrVO

In this work, platinum nanoparticles (Pt) decorated on a spinel group, zinc cobalt oxide (ZnCo2O4) 3-D flower was intended to detect caffeine electrochemical sensor. Pt particles were used to enhance the performance of hydrothermally prepared 3-D ZnCo2O4 flower. So Pt nanoparticles were decorated on each thin nanosheet of self-assembled 3-D flower-like ZnCo2O4. The thin transparent nanosheet of the ZnCo2O4 flower will benefit electrochemical sensors by simplifying its ion exchange. Therefore, Pt@ZnCo2O4 shows an excellent electrochemical conductivity, which promotes the caffeine-based sensor's rapid electrochemical oxidation. Using amperometric i-t at an applied potential of 1.45 V, Pt@ZnCo2O4 modified electrode shows widespread of two linear ranges (0.05 to 265.55 μM and 295.55 to 757.55 μM) with a low detection limit (0.0114 and 0.01657 μM) and high sensitivity (3.419 and 1.862 μA μM−1 cm−2). Moreover, good results were obtained for the real-time detection of caffeine in sugar-free cola beverage and energy drink samples. Henceforth, the developed method could be an ideal way to detect caffeine in real samples.

In this study, La0.8Sr0.2MnO3 (LSM) was used as the ceramic electrode in a (Bi1.50Y0.50)0.98Zr0.04O3+δ (BYO)-based solid electrolyte oxygen generator (SEOG) and its performance was compared with that of a previously studied high-fire Ag electrode. Among La0.6Sr0.4Co0.2Fe0.8O3, LaNi0.6Fe0.4O3, Cu1.4Mn1.6O4, and LSM materials, only LSM materials did not trigger any chemical reaction or interdiffusion with BYO at temperatures up to 900 °C. Two cell designs, Cell A, with a Bi1.71Nb0.25Ba0.04O3+δ (BBNO) interlayer and high-fire Ag electrode, and Cell B, with an LSM-BYO composite electrode, were obtained in this study. The cells were sandwiched between two modular SUS 316 planar interconnects using a ZnO–SiO2–Al2O3 glass sealant to form the SEOG device. Although Cells A and B possessed similar ohmic resistance (Ro) values, the polarization resistance (Rp) values of Cell A were 3.6 times larger than those of Cell B. Furthermore, the stability study of the cells operated at 600 °C for 12 h revealed that Ro increased from 0.79 to 3.17 Ω cm2 and Rp from 3.12 to 12.58 Ω cm2 for the Cell A, while Ro increased from 0.76 to 0.77 Ω cm2 and Rp from 0.87 to 1.12 Ω cm2 for the Cell B. Therefore, minor variations in the Ro and Rp of Cell B indicate the excellent stability of the electrode. The degradation of Cell A was caused by the migration of Ag and formation of voids and cracks adjacent to the anode/electrolyte interface under the DC field. Furthermore, the Cell A experienced a decrease in faradaic efficiency for current densities greater than 0.20 A cm−2 owing to the partial decomposition of BYO at the cathode. In contrast, the Cell B generated an oxygen flux of 1.29 cm⋅min−1 at 600 °C. In addition, the faradaic efficiency of Cell B remained consistent for current densities up to 0.35 A cm−2. Therefore, the SEOG using LSM-BYO as the cell electrode exhibited excellent stability and electrochemical performance.

Anacardium occidentale shell (AOS) biowaste was chemically activated using KOH at various temperatures to produce AC. Interestingly, this study also presents a novel strategy for achieving value-added usage of cashewnut shell in the energy storage field.

The aim of this work was to prepare and examine the catalytic activity of nanometric CeO2 decorated with transition metal oxides – Ni, Co, Cu, Fe and Mn – towards a high-temperature methanation process under SOEC CO2/H2O simulated co-electrolysis conditions. Samples were prepared using the wet impregnation method via the conventional process and with the addition of native cyclodextrin. The influence of β-cyclodextrin (βCD) onto the size, dispersion and integration of the obtained metal nanoparticles was investigated. The differences between the catalysts’ reducibility revealed that samples prepared from βCD-containing solutions, in most cases, resulted in the creation of smaller MexOy NPs on the surface of the substrate material compared to those prepared using traditional nitrate solutions. The samples containing Ni and Co were the only ones that observably catalysed methane synthesis. The high dispersion and integration of NPs prepared via the proposed synthesis route resulted in increased catalytic activity and enhanced stability, which was most pronounced for the Co-impregnated sample. The methane production peak for Ni-βCD/CeO2 at 375℃ was characterised by nearly 99% CO conversion and 80% selectivity towards CH4 production. Co-βCD/CeO2 reached 84% CO conversion and almost 60% methane selectivity at 450℃. The usage of CeO2 coupled with βCD for the preparation of catalysts for high-temperature methane synthesis for use in SOECs gave promising results for further application.

In this study, carbonaceous nanomaterials (Activated Carbon (AC), Graphene Oxide (GO) and Porous Graphene Oxide (PGO)) were synthesized and attached to Fe3O4 magnetic powder for the effective removal of synthetic Methyl Orange (MO). AC and GO were successfully conjugated with Fe3O4 whilst PGO was not due to its surface functional groups. The morphology and chemical structure of the Fe3O4/Carbon nanocomposites were characterized by the N2 adsorption, Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), Scanning electron microscope (SEM), Transmission electron microscope (TEM) and Vibrating sample magnetometer (VSM). Batch adsorption experiments were performed and showed significant removal efficiency of 90% at the first ten minutes for Fe3O4/AC nanocomposite. Analysis of adsorption equilibrium revealed that AC/Fe3O4 is well fitted with Langmuir model, a homogeneous adsorption having an adsorption capacity of 270 mg/g. The GO/Fe3O4 can fit with both Langmuir and Freundlich models indicating multilayer adsorption on the surface of the adsorbent with an adsorption capacity of 81.9 mg/g. In the case of adsorption kinetics, both adsorbents follow the pseudo second order kinetics model showing high F?2 values. Both adsorbents demonstrated advantageous superparamagnetic properties for their easy recovery from aqueous solutions and prospective applications to toxic removal in water and wastewater.

In the present work, MoS2 and WS2 catalysts were prepared by ultrasonic-assisted hydrothermal method to degrade the azo dye (reactive red 120). The prepared MoS2 and WS2 catalysts were confirmed by the different analytical techniques. The ultrasonic-assisted hydrothermal process enables the formation of highly crystalline MoS2 and WS2 nanoparticles. XPS result confirms the presence of divalent sulphide ions in both the samples and tetravalent tungsten and molybdenum. The formation of flower-like particles is confirmed by SEM and TEM. The photocatalytic activity of the MoS2 and WS2 towards reactive red 120 (RR120) was examined. Both the MoS2 and WS2 catalysts show 85% and 84% degradation ability against RR120. MoS2 and WS2 catalysts are highly stable and exhibit more than 77% and 75% after 4th cycle.

NdSrCo2O5+δ (NSCO) is a perovskite with an electrical conductivity of 1551.3 S cm−1 at 500 °C and 921.7 S cm−1 at 800 °C and has a metal-like temperature dependence. This perovskite is used as the cathode material for Ce0.8Gd0.2O2-δ (GDC)-supported microtubular solid oxide fuel cells (MT-SOFCs). The MT-SOFCs fabricated in this study consist of a bilayer anode, comprising a NiO–GDC composite layer and a NiO layer, and a NSCO–GDC composite cathode. Three cell designs with different outer tube diameters, GDC thicknesses, and NSCO/GDC ratios are designed. The MT-SOFC with an outer tube diameter of 1.86 mm, an electrolyte thickness of 180 μm, and a 5NSCO–5GDC composite cathode presents the best performance. The flexural strength of the aforementioned cell is 177 MPa, which is sufficient to confer mechanical integrity to the cell. Moreover, the ohmic and polarization resistance values of the cell are 0.22 and 0.09 Ω cm2 at 700 °C, respectively, and 0.15 and 0.03 Ω cm2 at 800 °C, respectively. These results indicate that the NSCO-GDC composite exhibits high electrochemical activity. The maximum power densities of the cell at 700 and 800 °C are 0.46 and 0.67 W cm−2, respectively, exceeding those of existing electrolyte-supported MT-SOFCs with similar electrolyte thicknesses.

Antibiotics are the most important drugs for people and animals to fight bacterial illnesses. Overuse of antibiotics has had unintended consequences, such as antibiotic resistance and ecosystem eradication owing to toxic chemical discharge, which have a negative influence on the biome. Herein, we report the synthesis of a hollow ellipsoid-shaped yttrium vanadate/graphitic carbon nitride (YVO4@CN) nanocomposite by a hydrothermal approach followed by a sonochemical method for the effective detection of dimetridazole (DMZ). The synergic and coupling effect between both the phases offer non-linear cumulative ramifications which can positively enhance the individual properties of the materials under consideration. This positive hybrid effect increases the conductivity, shortens the ion-diffusion pathway, enhances the electron/ion transportation, and provides more active sites and electron-conducting channels. The accurate optimization of the experimental conditions proposes good electrocatalytic activity for the YVO4@CN catalyst, exhibiting a good response toward DMZ detection. It reveals an extensive linear concentration range (0.001-153.3 and 176.64-351.6 μM), a low detection limit (0.8 nM), higher sensitivity (4.98 μA μM-1 cm-2), appreciable selectivity, increased operational stability (2200 s), and good cycle stability (60 cycles). The electrochemical performance of YVO4@CN indicates its practical application in real-time sample analysis of several families of nitroimidazole drugs.

The dielectric and structural properties of the as-quenched melts of three CaO–B2O3–SiO2 compositions (denoted CBS-1, CBS-2, and CBS-3) were investigated to determine their suitability for use in millimeter-wave applications. The CBS-1 glass-ceramic exhibited the lowest coefficient of thermal expansion (CTE = 3.2 ppm/°C), lowest dielectric constant (er = 4.04) at 60 GHz, and highest dielectric loss (tan δ = 0.0029) at 60 GHz, which were attributed to the presence of quartz (SiO2) as the major phase. In contrast, as the major phase constituent of the CBS-2 and CBS-3 glass-ceramics was β-CaSiO3, they presented relatively high CTEs (6.6 and 5.9 ppm/°C, respectively), relatively high dielectric constants at 60 GHz (6.29 and 7.61, respectively), and relatively low dielectric losses at 60 GHz (0.0020 and 0.0012, respectively). The CBS-1 glass-ceramic exhibited the highest dielectric loss because of the presence of SiO2 as the major phase constituent as well as lattice scattering induced by the high glassy phase content. The thermal conductivities (κ) of the CBS-1, CBS-2, and CBS-3 glass-ceramics were determined to be 2.43, 1.06, and 0.82 W/mK, respectively. Structural analysis using Raman and Fourier transform infrared spectroscopy revealed an absence of nonbridging oxygen in the CBS-1 glass-ceramic, while the high CaO content (>40 mol%) of the CBS-2 and CBS-3 glass-ceramics triggered the formation of nonbridging oxygen in the tetrahedral silicate units. The increase in CaO content of the glass-ceramics increased the number of nonbridging oxygen atoms, thereby resulting in the relaxation of the structure. Consequently, the CBS-2 and CBS-3 glass-ceramics exhibited low thermal conductivity. All the prepared glass-ceramics presented high electrical resistivities of greater than 5 × 1011 Ω cm. The CBS-1 glass-ceramic displayed the highest breakdown strength of 15.20 kV/mm. Overall, the excellent microwave dielectric properties and thermal properties of the CBS glass-ceramics will facilitate the utilization of these materials in millimeter-wave applications.

In this study, BaTi1-mZrmO3-4.5 mol.% Gd2O3-2.0 mol.% SiO2 ceramics with different Zr/Ti ratios and MgO contents were prepared via solid-state reaction. The MgO addition decreased the densification temperatures of the ceramics and increased the second phase Ba2GdZrO5.5 content. The temperature coefficient of capacitance curves of the ceramics had an almost linear variation with temperature, with negative temperature coefficients. With the increase of the Zr4+/Ti4+ ratio and MgO content, the temperature coefficient of capacitance rotated counter clockwise due to the lower Tm temperature, and a smaller tan δ and a higher electrical resistance were obtained at room temperature. The Zr4+ ion replacement and MgO addition reduced the $${\text{Ti}}^\prime_{{\text{Ti}}}$$ concentrations, and therefore, lessened the hopping conduction between Ti4+ and Ti3+ ions, while excess MgO produced $${V_O^{ \bullet \bullet }}$$ and had an opposing effect. Additionally, larger amounts of MgO led to smaller grain sizes, and thus, more insulating grain boundaries. The change in the dielectric constant with the bias field, a typical nonlinear dielectric behavior, decreased with increasing MgO content and Zr4+/Ti4+ ratio. For BaTi0.70Zr0.30O3 ceramics with additives of 6 mol.% MgO, 4.5 mol.% Gd2O3, and 2 mol.% SiO2, the dielectric constant changed by a minimum value of 0.37% under a bias of 2.5 kV/mm.

Rare-earth metal orthovanadates have great technological relevance in the family of rare-earth compounds owing to their excellent physical and chemical properties. A significant number of studies have been carried out on this class of compounds to exploit their electrochemical properties in virtue of variable oxidation states. But holmium vanadate (HoV) and its morphology selective synthesis have not been considered, which can have potential applications similar to the rest of the family. In this work, we propose the synthesis of superior architectures of HoV with a functionalized boron nitride (f-BN) nanocomposite. The synergistic effect between HoV and f-BN can have a positive effect on the physical characteristics of the nanocomposite, which can be explored for its electrochemical capacity. Here, HoV incorporated with f-BN is explored for the electrochemical detection of Hg2+ ions, which is known for its toxicity-induced environmental health hazards. The structural and compositional revelation reveals higher conductivity and faster electron transfer in the composite, which facilitates a wide working range (0.02-53.8 and 64.73-295.4 μM), low limit of detection (5 nM), higher sensitivity (66.6 μA μM-1 cm-2), good selectivity over 10-fold higher concentration of other interfering compounds compared to Hg2+ ion concentration, and good cycles stability (30 segments) toward Hg2+ ion detection. This also envisages the morphology selective synthesis and utilization of other rare-earth metals, whose electrochemical capacities are unexplored.

Pectin polymers are considered for lithium-ion battery electrodes. To understand the performance of pectin as an applied buffer layer, the electrical, magnetic, and optical properties of pectin films are investigated. This work describes a methodology for creating pectin films, including both pristine pectin and Fe-doped pectin, which are optically translucent, and explores their potential for lithium-ion battery application. The transmission response is found extended in optimally Fe-doped pectin, and prominent modes for cation bonding are identified. Fe doping enhances the conductivity observed in electrochemical impedance spectroscopy, and from the magnetic response of pectin evidence for Fe3+ is identified. The Li-ion half-cell prepared with pectin as binder for anode materials such as graphite shows stable charge capacity over long cycle life, and with slightly higher specific capacity compare with the cell prepared using polyvinylidene fluoride (PVDF) as binder. A novel enhanced charging specific capacity at a high C-rate is observed in cells with pectin binder, suggesting that within a certain rate (∼5 C), pectin has higher capacity at faster charge rates. The pectin system is found as a viable base material for organic–inorganic synthesis studies.

In this work, the hydrothermal method was used to synthesize f-BN@Bi

Trace level detection of drugs and hazardous analytes is more critical in electrochemical sensor. In this work, a simple sonochemical-assisted synthesis of Bismuth-EDTA complex/GO flakes was achieved and was developed to analyze mesalazine (MSA) sensing. The 3D hollow bricks were obtained for the Bi-EDTA complex without PVP. Surprisingly, PVP influenced the formation of broken glass-like structured for PVP with Bi-EDTA complex. Bi-EDTA complex modified GCE was developed to determine the role of PVP and its activity in electrochemical sensors. The results obtained by modifying the electrode Bi-EDTA complex with PVP showed good electrochemical performance compared to bare and other controls like GO and Bi-EDTA complex without PVP. The synergetic effect and high electroactive sites of Bi-EDTA complex/GO modified sensor implied low LOD (0.55 nM) and wide linear range from 0.005–585 µM. Furthermore, Bi-EDTA complex/GO showed an excellent selectivity in sensing MSA. Moreover, the Bi-EDTA complex exhibits advantages such as good stability, reproducibility, and repeatability. The modified Bi-EDTA complex/GCE sensor has been practically done to determine trace levels of MSA in human urine samples containing mesalamine tablets with satisfactory results.

In the field of agriculture fungicides are vital, providing the most important ecosystem service for food production. The widespread use of these chemicals can significantly lead to various ecotoxicological threats with adverse effects, such as environmental changes, microbial resistance, and phytotoxicity. Electrochemical sensors offer enormous potential for the identification and monitoring of hazardous substances in accordance with their constructive characteristics, namely, precision, accuracy, sensitivity, and selectivity, over traditional analytical techniques. Here, we thus report the synthesis of the lanthanum vanadate/hexagonal boron nitride (LaV/h-BN) composite for the electrochemical determination of carbendazim (CZ), which is a widely used fungicide for disease management with critical risks associated with its overexposure. The combination of LaV and h-BN accelerates the formation of active sites, facilitating faster charge transfer and higher electronic conductivity. The synergistic effects greatly improve the preference of the modified electrode with increased sensitivity, a lower limit of detection, and wide linear responses toward CZ detection. The existence of variable oxidation states in the orthovanadate together with the unique properties of h-BN mark LaV/h-BN as an advanced material for specific applications in the family of rare-earth metal orthovanadate. Also, the deep eutectic solvent-assisted synthesis of the material creates an environmentally efficient system with reduced energy requisites to allow for applications in effective environmental monitoring.