Francisjunker5374

Calcium Copper Titanium Oxide (CaCu3Ti4O12/CCTO) has grasped massive attention for its colossal dielectric constant in high operating frequencies and wide temperature range. However, the synthesis and processing of CCTO directly influence the material's properties, imparting the overall performance. Researchers have extensively probed into these downsides, but the need for a new and novel approach has been in high demand. Modern synthesis routes and advanced non-conventional sintering techniques have been employed to curb the drawbacks for better properties and performance. This review provides a short overview of the modern synthesis and sintering methods that utilize direct pulse current and electromagnetic waves to improve the material's electrical, optical, and dielectric properties in the best ways possible. In addition, the current application of CCTO as a photocatalyst under visible light and CuO's role in the efficient degradation of pollutants in replacement for other metal oxides has been reviewed. This research also provides a brief overview of using CCTO as a photoelectrode in zinc-air batteries (ZAB) to improve the Oxidation-reduction and evolution (ORR/OER) reactions.In the present study, we report on the successful synthesis of hollow iron oxide nanospheres. The hollow Fe3O4 nanospheres were synthesized following a four-step procedure electrospraying spherical PVP particles, coating these particles with alumina (Al2O3) and hematite (Fe2O3) through atomic layer deposition and, finally, a thermal reduction process to degrade the polymer (PVP) and convert hematite (Fe2O3) into magnetite (Fe3O4). A structural analysis using X-ray diffraction (XRD) confirmed the effectiveness of the thermal reduction process. A morphological analysis confirmed that the four-step procedure allowed for the obtainment of hollow iron oxide nanospheres, even though the reduction process caused a contraction in the diameter of the particles of almost 300 nm, but did not affect the thickness of the walls of the hollow spheres that remained at approximately 15 nm. Magnetic properties of the hollow iron oxide nanospheres enable their use in applications where the agglomeration of magnetic nanostructures in liquid media is commonly not allowed, such as in drug encapsulation and delivery.Carbon material-based aerogels (CMBAs) have three-dimensional porous structure, high specific surface area, low density, high thermal stability, good electric conductivity, and abundant surface-active sites, and, therefore, have shown great application potential in energy storage, environmental remediation, electrochemical catalysis, biomedicine, analytical science, electronic devices, and others. In this work, we present recent progress on the fabrication, structural design, functional tailoring, and gas adsorption applications of CMBAs, which are prepared by precursor materials, such as polymer-derived carbon, carbon nanotubes, carbon nanofibers, graphene, graphene-like carbides, fullerenes, and carbon dots. To achieve this aim, first we introduce the fabrication methods of various aerogels, and, then, discuss the strategies for regulating the structures of CMBAs by adjusting the porosity and periodicity. In addition, the hybridization of CMBAs with other nanomaterials for enhanced properties and functions is demonstrated and discussed through presenting the synthesis processes of various CMBAs. After that, the adsorption performances and mechanisms of functional CMBAs towards CO2, CO, H2S, H2, and organic gases are analyzed in detail. Finally, we provide our own viewpoints on the possible development directions and prospects of this promising research topic. We believe this work is valuable for readers to understand the synthesis methods and functional tailoring of CMBAs, and, meanwhile, to promote the applications of CMBAs in environmental analysis and safety monitoring of harmful gases.Electro-optical tuning metasurfaces are particularly attractive since they open up routes for dynamic reconfiguration. The electro-optic (EO) modulation strength essentially depends on the sensitivity to the EO-induced refractive index changes. In this paper, lithium niobate (LiNbO3) metasurfaces integrated with liquid crystals (LCs) are theoretically investigated. Cylinder arrays are proposed to support quasi-bound states in the continuum (quasi-BICs). The quasi-BIC resonances can significantly enhance the lifetime of photons and the local field, contributing to the EO-refractive index changes. By integrating metasurfaces with LCs, the combined influence of the LC reorientation and the Pockels electro-optic effect of LiNbO3 is leveraged to tune the transmitted wavelength and phase spectrum around the quasi-BIC wavelength, resulting in an outstanding tuning sensitivity up to Δλ/ΔV ≈ 0.6 nm/V and relieving the need of high voltage. Furthermore, the proposed structure can alleviate the negative influence of sidewall tilt on device performance. The results presented in this work can foster wide application and prospects for the implementation of tunable displays, light detection and ranging (LiDAR), and spatial light modulators (SLMs).The density, microstructure, and ionic conductivity of solid electrolyte Li1.3Al0.3Ti1.7(PO4)3 (LATP) ceramics prepared by cold sintering using liquid and solid sintering additives are studied. The effects of both liquid (water and water solutions of acetic acid and lithium hydroxide) and solid (lithium acetate) additives on densification are investigated. The properties of cold-sintered LATP are compared to those of conventionally sintered LATP. The materials cold-sintered at temperatures 140-280 °C and pressures 510-600 MPa show relative density in the range of 90-98% of LATP's theoretical value, comparable or higher than the density of conventionally sintered ceramics. With the relative density of 94%, a total ionic conductivity of 1.26 × 10-5 S/cm (room temperature) is achieved by cold sintering at the temperature of 200 °C and uniaxial pressure of 510 MPa using water as additive. The lower ionic conductivities of the cold-sintered ceramics compared to those prepared by conventional sintering are attributed to the formation of amorphous secondary phases in the intergranular regions depending on the type of additives used and on the processing conditions selected.Influence on photocurrent sensitivity of hydrothermally synthesized electrochemically active graphene quantum dots on conjugated polymer utilized for a novel single-layer device has been performed. Fabrications of high-performance ultraviolet photodetector by depositing the polypyrrole-graphene quantum dots (PPy-GQDs) active layer of the ITO electrode were exposed to an Ultraviolet (UV) source with 265 and 355 nm wavelengths for about 200 s, and we examined the time-dependent photoresponse. The excellent performance of GQDs was exploited as a light absorber, acting as an electron donor to improve the carrier concentration. PGC4 exhibits high photoresponsivity up to the 2.33 µA/W at 6 V bias and the photocurrent changes from 2.9 to 18 µA. The electrochemical measurement was studied using an electrochemical workstation. The cyclic voltammetry (CV) results show that the hysteresis loop is optically tunable with a UV light source with 265 and 355 nm at 0.1 to 0.5 V/s. The photocurrent response in PPy-GQDs devices may be applicable to optoelectronics devices.Composite nanostructures containing iron in different forms exhibit a high adsorption capacity with respect to arsenic. The aim of our study was to investigate the adsorption activity of an adsorbent composite prepared by the oxidation of bimetallic Al/Fe nanoparticles under different conditions. Depending on the oxidation conditions, nanostructures with different morphologies in the form of nanosheets, nanoplates and nanorods with different compositions and textural characteristics could be obtained. The nanostructures obtained had a positive zeta potential and were characterized by a high specific surface area 330 m2/g for the AlOOH/FeAl2 nanosheets; 75 m2/g for the AlOOH/Fe2O3/FeAl2 nanoplates; and 43 m2/g for the Al(OH)3/FeAl2 nanorods. The distribution of an FeAl2 intermetallide over the surface of the AlOOH nanostructures led to an increase in arsenic adsorption of 25% for the AlOOH/FeAl2 nanosheets and of 34% for the AlOOH/Fe2O3/FeAl2 nanoplates and Al(OH)3/FeAl2 nanorods. The adsorption isotherms matched most preciously to the Freundlich model. This fact indicated the energy heterogeneity of the adsorbent surface and multilayer adsorption. The nanostructures studied can be used to purify water contaminated with arsenic.Colloidal nano-silica (CNS) was used to improve the mechanical and impermeability characteristics of mortar in this study. The samples were prepared with 0%, 1%, 2% and 3% (solid content) CNS addition. The mechanical strength and permeability of each mixture was studied, and the mechanism behind was revealed by hydration heat evolution, XRD, DSC-DTG, 29Si MAS-NMR and SEM-EDS analysis. The compressive strength and impermeability characteristics of mortars incorporating CNS were significantly improved. progestogen Receptor antagonist The experimental results demonstrated that the incorporation of CNS promoted the early hydration process of cement, thus increasing the polymerization degree of hydrated calcium silicate, decreasing the porosity, and improving the microstructure of mortar. Furthermore, 3% CNS decreased the Ca/Si ratio of the interfacial transition zone (ITZ) from 3.18 to 2.22, thus the enrichment of CH was reduced and the density and strength were improved. This was mainly because of the high pozzolanic activity of CNS, which consumed plenty of calcium hydroxide and converted to C-S-H. Besides, nanoscale CNS and C-S-H particles filled the voids between hydrates, thus refining the pore size, increasing the complexity of pores, and improving the microstructure of ITZ which contributed to the improvement of the impermeability.Colloidal semiconductor quantum dots (QD), as well as other nanoparticles, are useful in cell studies as fluorescent labels. They may also be used as more active components in various cellular assays, serving as sensors or effectors. However, not all QDs are biocompatible. One of the main problems is their outer coat, which needs to be stable and to sustain hydrophilicity. Here we show that purpose-designed CdSe QDs, covered with a Puf protein, can be efficiently accumulated by HeLa cells. The uptake was measurable after a few hours of incubation with nanoparticles and most of the fluorescence was localised in the internal membrane system of the cell, including the endoplasmic reticulum and the Golgi apparatus. The fluorescence properties of QDs were mostly preserved, although the maximum emission wavelength was slightly shifted, and the fluorescence lifetime was shortened, indicating partial sensitivity of the QDs to the cell microenvironment. QD accumulation resulted in a decrease in cell viability, which was attributed to disturbance of endoplasmic reticulum performance.Photovoltaic technology is currently at the heart of the energy transition in our pursuit to lean off fossil-fuel-based energy sources. Understanding the workings and trends of the technology is crucial, given the reality. With most conventional PV cells constrained by the Shockley-Queisser limit, new alternatives have been developed to surpass it. One of such variations are heterojunction cells, which, by combining different semiconductor materials, break free from the previous constraint, leveraging the advantages of both compounds. A subset of these cells are multi-junction cells, in their various configurations. These build upon the heterojunction concept, combining several junctions in a cell-a strategy that has placed them as the champions in terms of conversion efficiency. With the aim of modelling a multi-junction cell, several optic and optoelectronic models were developed using a Finite Element Tool. Following this, a study was conducted on the exciting and promising technology that are nanoantenna arrays, with the final goal of integrating both technologies.