Facile Synthesis ZnS/ZnO/Ni(OH)2 Composites Grown on Ni Foam: A Bifunctional Materials for Photocatalysts and Supercapacitors

Novel electrospun bead-like Ag2MoO4 nanofibers coated on Ni foam for visible light-driven heterogeneous photocatalysis and high-performance supercapacitor electrodes

Novel Ag2MoO4 nanocomposite fibers were designed to enhance the photocatalytic response and supercapacitor performance of MoO3 grown via the sol-gel electrospinning technique. The Ag2MoO4 nanocomposite fibers exhibit a high specific surface area of 49.3 m2 g-1 comprising nanobeads that aggregate in the fibrous structure. The photodegradation efficiency of Ag2MoO4 was evaluated as 62% under visible light irradiation which improved to 71% with heterogeneous photocatalysis. The Ag2MoO4@Ni foam exhibited a low Rct of 19.6 Ω, and an enhanced specific capacitance of 1445 F g-1 was obtained at 1 A g-1, with 93% of its initial capacitance remaining after 5000 cycles. In addition, the Ag2MoO4//activated carbon asymmetric supercapacitor possesses an excellent energy density of 76.6 W h kg-1 at 743.2 W kg-1 and a noteworthy cycling durability of 91% after 5000 cycles. Our findings demonstrate that the electrospun Ag2MoO4@Ni foam is an important and inexpensive electrode material for supercapacitor applications and visible light-driven heterogeneous photocatalysis, drawing on the synergic effects of Ag and Mo to exhibit much better performance.

Dose-Dependent Efficacy of Umbelliferone and Gelatin-Coated ZnO/ZnS Core-Shell Nanoparticles: A Novel Arthritis Agent for Severe Knee Arthritis

Rheumatoid arthritis (RA) is a well-known autoimmune disorder that affects 1% of the global population. Zinc (Zn) is crucial for bone homeostasis, when compared with normal human bone, Zn level found to be decreased in RA patients and collagen-induced arthritis (CIA) rats. Notably, Zn-based medicinal products play a prominent role in reducing disease symptoms and acute side effects of patients with bone-related diseases. In this study, we report the clinical efficiency of gelatin- (Gel-) coated ZnO-ZnS core-shell nanoparticles (CSNPs) with umbelliferon (Uf) drug (Uf-Gel-ZnO-ZnS CSNPs) on the normal and CIA-induced Wistar rats. The formed ZnO-ZnS CSNPs are spherical in shape, with an average particle diameter of 150 ± 7 nm. It showed strong cytocompatibility when tested on L929 and foreskin fibroblasts (BJ) cells by MTT assay. While comparing with free Uf, various doses (2.5 and 5 mg) of Uf-Gel-ZnO-ZnS CSNPs showed strong inhibition of CIA by attenuated proinflammatory cytokines such as interleukin-1β, IL-6, PEG2, and IL-17. The Uf-Gel-ZnO-ZnS CSNPs show more effectiveness in reducing joint swelling and also increase the level of antioxidant enzymes. In addition, CSNPs significantly reduced the infiltration of inflammatory cells in the knee joint. Thus, the current study concludes that Uf-Gel-ZnO-ZnS CSNPs feasibly reduce the incidence of arthritis in a dose-dependent manner by attenuation of inflammation.

Metal-bio functionalized bismuthmagnetite [Fe3-x Bi x O4/SiO2@l-ArgEt3 +I-/Zn(ii)]: a novel bionanocomposite for the synthesis of 1,2,4,5-tetrahydro-2,4-dioxobenzo[b][1,4]diazepine malononitriles and malonamides at room temperature and under sonication

In this work, a new magnetized composite of bismuth (Fe3-x Bi x O4) was prepared and functionalized stepwise with silica, triethylargininium iodide ionic liquid, and Zn(ii) to prepare a multi-layered core-shell bio-nanostructure, [Fe3-x Bi x O4/SiO2@l-ArgEt3 +I-/Zn(ii)]. The modified bismuth magnetic amino acid-containing nanocomposite was characterized using several techniques including Fourier-transform infrared (FT-IR), X-ray fluorescence (XRF), vibrating sample magnetometer (VSM), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDAX), thermogravimetric/differential scanning calorimetric (TGA/DSC) analysis, X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), and inductively coupled plasma-optical emission spectrometry (ICP-OES). The magnetized bionanocomposite exhibited high catalytic activity for the synthesis of 1,2,4,5-tetrahydro-2,4-dioxobenzo[b][1,4]diazepine malononitriles via five-component reactions between 1,2-phenylenediamines, Meldrum's acid, malononitrile, aldehydes, and isocyanides at room temperature in ethanol. The efficacy of this protocol was also examined to obtain malonamide derivatives via pseudo six-component reactions of 1,4-phenylenediamine, Meldrum's acid, malononitrile, aldehydes, and isocyanides. When the above-mentioned MCRs were repeated under the same conditions with the application of sonication, a notable decrease in the reaction time was observed. The recovery and reusability of the metal-bio functionalized bismuthmagnetite were examined successfully in 3 runs. Furthermore, the characteristics of the recovered Fe3-x Bi x O4/SiO2@l-ArgEt3 +I-/Zn(ii) were investigated though FESEM and EDAX analysis.

Monodispersed core/shell nanospheres of ZnS/NiO with enhanced H2 generation and quantum efficiency at versatile photocatalytic conditions

This investigation is first to elucidate the synthesis of mono-dispersed ZnS/NiO-core/shell nanostructures with a uniform thin layer of NiO-shell on the ZnS-nanospheres as a core under controlled thermal treatments. NiO-shell thickness varied to 8.2, 12.4, 18.2, and 24.2 nm, while the ZnS-core diameter remained stable about 96 ± 6 nm. The crystalline phase and core/shell structure of the materials were confirmed using XRD and HRTEM techniques, respectively. Optical properties through UV-vis spectroscopy analysis revealed the manifestation of red-shift in the absorption spectrum of core/shell materials, while the XPS analysis of elements elucidated their stable oxidation states in ZnS/NiO core/shell structure. The optimized ZnS/NiO-core/shell showed 1.42 times higher H₂ generation (162.1 mmol h^-1 g^-1_cat) than the pristine ZnS-core (113.2 mmol h^-1 g^-1_cat), and 64.5 times higher than the pristine NiO-shell (2.5 mmol h^-1 g^-1_cat). The quantum efficiency at wavelengths of 420, 365 nm, and 1.5 G air mass filters was found to be 13.5%, 25.0%, and 45.3%, respectively. Water splitting experiments was also performed without addition of any additives, which showed enhanced H₂ gas evolution of 1.6 mmol h^-1 g^-1_cat under the sunlight illumination. Photoelectrochemical measurements revealed the stable photocurrent density and minimized charge recombination in the system. The performed recyclability and reusability tests for five recycles demonstrated the excellent stability of the developed photocatalysts.

Ethylenediamine-assisted growth of multi-dimensional ZnS nanostructures and study of its charge transfer mechanism on supercapacitor electrode and photocatalytic performance

In recent years, much interest has been raised by materials with multi-purpose characteristics as the performance of electrochemical energy devices such as supercapacitors and photocatalytic activities depend strongly on the properties of materials. This study delineates various parameters like morphology, energy band gap, charge transfer resistance, different defect states, diffusion coefficient and functional groups adsorbed on the surface of material to assess the performance of supercapacitor electrodes and photocatalytic degradation efficiency of synthesised multi-dimensional ZnS nanostructures. Ethylenediamine (EN)-mediated multi-dimensional ZnS nanostructures were grown by the solvothermal route. One-dimensional (1D), 2D and 3D morphologies were obtained by varying the ratio of de-ionised water and EN, taken as 1:3, 1:2 and 1:1, respectively. The EN molecules effectively capped most of the surfaces of the ZnS nanoparticles formed, preventing agglomeration of nanoparticles due to the decrement in surface energy. The oriented attachment of these clusters resulted in the formation of 1D, 2D and 3D morphologies. The plausible chemistry in the formation of 1D, 2D and 3D nanostructures has been elaborated. Charge transfer properties of prepared electrodes have been examined using the electrochemical impedance spectroscopy (EIS) technique because better charge transfer causes diminishing electron/hole recombination and hence better photodegradation efficiency. Among the synthesised materials, the 2D nanostructure degraded the eosin Y dye to maximum 90.71% efficiency with rate constant 34 × 10^-3 min^-1. 2D nanostructures possess better charge transfer and hence better photodegradation efficiency. Various studies using methods of UV-vis, Fourier-transform infrared, Brunauer-Emmett-Teller, x-ray photoelectron spectroscopy and photoluminescence spectra are in good agreement with the obtained photodegradation results. After analysing cyclic voltammetry curves and EIS, a higher diffusion coefficient is obtained for 1D nanostructure material, hence a higher specific capacitance and higher energy density of 159.12 F g^-1 and 22.75 KWh kg^-1 are found in this case. Only 9% loss of specific capacitance is found after 1000 cycles, showing a relatively high cycling stability in 3D nanostructures. The excellent supercapacitive property can be attributed to the porous structure and high specific surface area. Thus, the synthesised multi-dimensional ZnS nanostructures are proved to be a potential candidate for both photocatalytic and supercapacitor electrode performance.

Synthesis of Ni2+ ion doped ZnO–MWCNTs nanocomposites using an in situ sol–gel method: an ultra sensitive non-enzymatic uric acid sensing electrode material

Nickel (Ni²⁺) ion doped zinc oxide-multi-wall carbon nanotubes (NZC) with different composition ratios of MWCNTs (from 0.01 to 0.1 wt%) are synthesized through an in situ sol–gel method. The synthesized NZC nanocomposites (NCs) are used as electrode materials with glassy carbon electrodes (GCEs) for electrochemical detection of uric acid (UA). The cyclic voltammogram of the representative NZC 0.1 modified GCE (NZC 0.1/GCE) revealed the highest electrochemical sensing activity towards the oxidation of UA at 0.37 V in 0.2 M phosphate buffer solution (PBS) having pH 7.4 ± 0.02. The limit of detection (LOD) and limit of quantification (LOQ) for the NZC 0.1/GCE are determined to be 5.72 nM and 19.00 nM (S/N = 3) respectively, which is the lowest compared to the literature values reported for enzymatic and non-enzymatic detection techniques. The synergistic effect of NZC 0.1 NCs is proposed as one of the factors for the enhanced electrochemical oxidation of UA complemented by the phase, lattice parameters, functional groups, morphology, elemental compositions, types of bonding and specific surface area with pore size ascertained using various techniques. The synthesized NZC 0.1 NCs are further proposed as selective electrode materials for the electrochemical detection of UA as authenticated further by performing interference tests with other metabolites such as ascorbic acid (AA), dopamine (DA) and d-glucose. The optimized electrochemical studies are further adopted for sensing of UA from human excretion samples using NZC 0.1 NCs.

Nickel (Ni²⁺) ion doped zinc oxide-multi-wall carbon nanotubes (NZC) with different composition ratios of MWCNTs (from 0.01 to 0.1 wt%) are synthesized through an in situ sol–gel method.

Facile synthesis of NF/ZnOx and NF/CoOx nanostructures for high performance supercapacitor electrode materials

NF/ZnOx nanocone and NF/CoOx nanoparticle electrode materials were fabricated on a nickel foam surface using a simple chemical bath deposition approach and assessed as an electrode material for high-performance supercapacitors.