RESUMEN
A series of cobalt-inserted copper zinc ferrites, Cu0.6CoxZn0.4-xFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4) having cubic spinel structure were prepared by the coprecipitation method. Various characterization techniques, including XRD, FTIR, UV-vis and I-V were used to investigate structural optical and electrical properties, respectively. The lattice constant was observed to be decreased as smaller ionic radii Co2+ (0.74 Å) replaced the higher ionic radii Zn2+ (0.82 Å). The presence of tetrahedral and octahedral bands was confirmed by FTIR spectra. Optical bandgap energy was determined in the range of 4.44-2.05 eV for x = 0.0 to 0.4 nanoferrites, respectively. DC electrical resistivity was measured and showed an increasing trend (5.42 × 108 to 6.48 × 108 Ω·cm) with the addition of cobalt contents as cobalt is more conductive than zinc. The range of DC electrical resistivity (108 ohm-cm) makes these nanomaterials potential candidates for telecommunication devices.
Asunto(s)
Compuestos Férricos/química , Cobre/química , Conductividad Eléctrica , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X , Óxido de Zinc/químicaRESUMEN
Zinc is an essential trace metal and its concentration above 4ppm reduces the aesthetic value of water. This study explores the possibility of using functionalized nanohybrids as Zn(II) ion scavengers from aqueous solution. Functionalized nanohybrids were synthesized by the attachment of thiosemicarbazide to silica. The material was characterized by TGA, SEM, FTIR, EDX, and BET analysis, which revealed ligand bonding to silica. The functionalized silica was employed as Zn(II) ion extractant in batch experiments and removed about 94.5% of the Zn(II) ions at pH 7, near zero point charge (6.5) in 30 min. Kinetics investigations revealed that zinc adsorption follows an intra particle diffusion mechanism and first-order kinetics (K = 0.1020 min-1). The data were fitted to Freundlich, Dubinin-Radushkevich, and Langmuir models and useful ion exchange parameters were determined. The impact of co-existing ions on Zn(II) ion sequestration was also studied and it was found that the adsorbent can be used for selective removal of zinc with various ions in the matrix. Quantum mechanical investigations revealed that the Zn(II) ion adsorption on ZnBS1 is more favorable, having higher binding energy (BE) (-178.1 kcal/mol) and ∆H (-169.8), and making tridentate complex with the N and S sites of the chelating ligand. The negative ∆G and BE values suggest highly spontaneous Zn(II) adsorption on the modified silica even at low temperatures.
Asunto(s)
Iones/química , Nanopartículas/química , Dióxido de Silicio/química , Zinc/química , Adsorción , Algoritmos , Técnicas de Química Sintética , Teoría Funcional de la Densidad , Modelos Moleculares , Modelos Teóricos , Relación Estructura-Actividad , TermogravimetríaRESUMEN
In dentistry, bone regeneration in areas following tooth loss, the removal of a tumor or cyst, and craniofacial surgery can be accomplished by using bone grafts. Many biocompatible materials have been employed for bone regeneration in dentistry; however, all these bone graft materials come with various drawbacks. Therefore, there is a growing demand for natural, cost-effective, and biocompatible plant-based bone grafts. This review explores the emerging field of phytogenic elements in bone restoration and their specific applications in dentistry. The review focuses on key phytogenic compounds, such as algae-based and plant-based bone substitutes, delineating their roles in bone regeneration in dental bone defects. It also highlights the existing challenges associated with phytogenic grafts, such as limited bioavailability and high-dose toxicity. This calls for increased research into compatible, affordable carriers and a broader spectrum of studies to determine the most effective phytogenic solutions in dental regenerative medicine.
RESUMEN
This paper reports on the synthesis of ZnO nanowires (NWs), as well asthe compound nanostructures of nanoparticles (NPs) and nanowires (NWs+NPs) with different coating layers of NPs on the top of NWs and their integration in dye-sensitized solar cells (DSSCs). In compound nanostructures, NWs offer direct electrical pathways for fast electron transfer, and the NPs of ZnOdispread and fill the interstices between the NWs of ZnO, offering a huge surface area for enough dye anchoring and promoting light harvesting. A significant photocurrent density of 2.64 mA/cm2 and energy conversion efficiency of 1.43% was obtained with NWs-based DSSCs. The total solar-to-electric energy conversion efficiency of the NWs+a single layer of NPs was found to be 2.28%, with a short-circuit photocurrent density (JSC) of 3.02 mA/cm2, open-circuit voltage (VOC) of 0.74 V, and a fill factor (FF) of 0.76, which is 60% higher than that of NWs cells and over 165% higher than NWs+a triple layer of NPs-based DSSCs. The improved performance was obtained due to the increased specific surface area for higher dye anchoring and light harvesting of compound nanostructures with NWs+a single layer of NPs.