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Lead-free BiFeO3-BaTiO3 ceramics attract widespread attention over the last two decades due to their high Curie temperature (TC) and excellent piezoelectric performance. Here, in the Nd-modified 0.67BiFeO3-0.33BaTiO3 ceramics, an excellent piezoelectric constant (d33) of 325 pC/N was achieved by applying a novel poling method (AC-bias + DC-bias) with a high TC of 455 °C. In addition, an ultrahigh normalized piezoelectric strain (d33∗ = Smax/Emax) of 808 pm/V was obtained at the normal/typical and relaxor-ferroelectrics phase boundary simultaneously with good thermal stability (Δd33∗(T) ≈ 20%) in the temperature range of 25–125 °C. The piezoelectric force microscopy results show the domain miniaturization from micro to nanoscale/polar nano-regions due to local structure heterogeneity caused by Nd doping. The mechanism for the giant piezoelectric strain is attributed to the thermal quenching, nano-domains, and reverse switching of the short-range order to the long-range order under the applied electric field. The strategic design of domain engineering and a proposed model for the high piezoelectricity is successfully supported by the phenomenological relation and Gibbs free energy profile. In this work, a new lead-free single-element modified BiFeO3-BaTiO3 ceramics was developed by applying a synergistic approach of domain engineering and phase boundary for the high-temperature piezoelectric performance.

In the current study, novel (Y2O3) x (CdO) 1-x mixed oxides nanocomposites (NCs) with different Y2O3 loadings (0.0 ≤ x ≤ 0.2) have been synthesized via a facile precipitation approach. The structural analysis by x-ray diffraction reveals that both pure CdO nanoparticles (NPs) and (Y2O3) x (CdO) 1-x NCs possess crystalline and cubic-phase purity. The crystallite size in the mixing nanocomposition (NCs) ranged from 45 to 52 nm based on the concentration of Y2O3 in the NCs. The morphologies of CdO NPs and (Y2O3) x (CdO) 1-x NCs were studied using field emission scanning electron microscopy. This confirmed that the collected NCs had an irregular semi-spherical morphology. It was established, based on the Tauc figure, that the optical band gap of the produced NCs had lowered from 3.35 to 2.96. Testing conducted by Brunauer-Emmett-Teller (BET) reveals that an increase in surface area and pore volume following the addition of Y2O3 is indicative of increased porosity. UV-vis spectroscopy's optical study reveals that Y2O3 loading significantly improves the photocatalytic activities of (Y2O3) x (CdO) 1-x NCs. The photodegradation efficiency of methylene blue (MB) was higher (94.6%) for the (Y2O3) 0.2 (CdO) 0.8 NCs under solar irradiation compared to (45.6%) for pure CdO NPs. The (Y2O3) 0.2 (CdO) 0.8 NCs photocatalyst was stable in six cycles of MB degradation, according to a study on reusability. Optimal Y2O3 loading in the photocatalytic system is responsible for the boost in photocatalytic activity due to the system's high BET-surface area, narrow size distribution, and narrow energy band gap.

Buckypaper membranes were prepared through the dispersion of multi-walled carbon nanotubes (MWCNTs) in the presence of surfactants (Triton X-100) and (PVA) in a separate manner. The dispersed solutions were vacuum filtered and Buckypapers, which are self-supporting membranes were obtained. The results revealed that the incorporation of both Triton X-100 and PVA surfactants increased the permeability and rejection efficiency of the MWCNTs. The rejection performance for the heavy metal ions of both membranes is investigated for the first time. The physico-chemical and morphological characteristics of the membranes were reported. PVA and Triton X-100 BP membranes displayed electrical conductivity (32.749 ± 2 S cm−1 and 58.3072 ± 1 S cm−1), contact angle (58 ± 3° and 34 ± 3°), water permeability (20 ± 2 Lm−2 h−1 bar−1 and 79 ± 4 Lm−2 h−1 bar−1), surface area (67.7 and 88.5 m2/g) and mechanical properties (Young's module was found to be 10.25 ± 0.2 and 6.07 ± 0.7) respectively. Both PVA/MWCNTs BP and Trix-100/MWCNTs BP membranes significantly reject Cu+2, Cd+2, Co+2, Ba+2, Ni+2, and Pb+2 at PH = 6–8 from aqueous medium. Furthermore, the rejection of metal ions was more efficient in PVA-based membranes compared to Trix-based membranes.

Given the rising consumption of plastic products, it is becoming imperative to prioritize the recycling of plastic items as a solution to reducing plastic waste and environmental pollution. In this context, this research focuses on assessing the impact of incorporating rice husk and wood flour into recycled high-density polyethylene (rec-HDPE) to analyze its mechanical properties, flammability, and thermal stability. The combined rec-HDPE content of wood flour and rice husk varied between 0% and 20%. The rec-HDPE content of maleic anhydride grafted polyethylene (MAPE) was fixed at 3%. Mechanical characteristics such as flexural, tensile, and impact strengths were assessed. Cone calorimetry (CC) tests, limited oxygen index (LOI) tests, and horizontal and vertical burning tests were performed to determine the flammability or fire retardancy of these composites. On the other hand, to characterize the thermal characteristics of these composites, thermogravimetric analysis (TGA) was used. To further characterize the fluctuation in these characteristics, scanning electron microscopy (SEM) and infrared spectroscopy (FTIR) studies were carried out. The mechanical characteristics were found to be increased in response to adding rice husk or wood flour. An 8% increase in tensile strength and a 20% increase in elastic modulus enhancement were recorded for a 20% rice husk-added composite. SEM revealed the reason for the variation in tensile properties, based on the extent of agglomeration and the extent of uniform distribution of fillers in rec-HDPE. Following these lines, the 20% rice husk-added composite also showed a maximum increase of around 6% in its flexural strength and a maximum increase of 50% in its flexural modulus. A decrease in impact strength was recorded for rice husk and wood flour-reinforced composites, compared with unreinforced rec-HDPE. Hybrid composites displayed a lack of mechanical strength due to changes in their nature. FTIR tests were performed for a much more elaborate analysis to confirm these results. Twenty percent of rice husk-added rec-HDPE displayed the best thermal properties that were tested, based on TGA and derivative thermogravimetric (DTG) analysis. This 20% composite also displayed the best fire-retardancy characteristics according to UL 94 tests, cone calorimetry tests, and limited oxygen index tests, due to the barrier created by the silica protective layer. These tests demonstrated that the incorporation of both fillers—rice husk and wood flour—effectively enhanced the thermal, mechanical, and fire-retardant attributes of recycled HDPE.

Abstract This work aims to test the effectiveness of newly developed DFT-1/2 functional in calculating the electronic and optical properties of inorganic lead halide perovskites CsPbBr3. Herein, from DFT-1/2 we have obtained the direct band gap of 2.36 eV and 3.82 eV for orthorhombic bulk and 001-surface, respectively. The calculated energy band gap is in qualitative agreement with the experimental findings. The bandgap of ultra-thin film of CsPbBr3 is found to be 3.82 eV, which is more than the expected range 1.23-3.10 eV. However, we have found that the bandgap can be reduced by increasing the surface thickness. Thus, the system under investigation looks promising for optoelectronic and photocatalysis applications, due to the bandgap matching and high optical absorption in UV–Vis (Ultra violet and visible spectrum) range of electro-magnetic(em) radiation.

Phase change material (PCM)-based thermal energy storage units (TESU) have very low thermal conductivity that compromise their charging and discharging rate. The present study focuses on an enhancement in charging rate as well as an increase in the uniformity of the melting rate. A rectangular cavity consisting of two horizontal partial fins is studied. The horizontal partial fins are placed symmetrically in a PCM-based TESU. In the current work, the melting rate of PCM was enhanced using asymmetric arrangement while keeping all other parameters the same, thus showing the positive effect of asymmetric configuration in such storage systems. The position and the pitch of each fin is optimized to improve heat transfer characteristics of the TESU. The numerical investigation of the problem is performed. TESU with asymmetrically placed fins show better performance in terms of higher charging rate as well as uniformity of the charging rate. The asymmetric placement of the fins suggested by present study increased the charging rate by 74.3% on average as compared to the symmetrically placed fins in the storage system. The charging rate uniformity is improved by 43.7%. The asymmetric fin’s placement conserved the convection strength for a longer melting duration and so increased the Nusselt number by 80.2% as compared to the symmetrically placed fins. Thus, it can be concluded that the performance of asymmetric fins is better in the charging of PCMs than the symmetrically placed fins in a PCM-based TESU.

This study describes the synthesis of delafossite, CuFeO2, as a primary photocatalytic material for hydrogen generation. A photoelectrode, CuFeO2/CuO/Cu, was prepared by combusting a Cu foil dipped in FeCl3 in ambient air. This photoelectrode showed excellent optical behavior for the hydrogen generation reaction from sewage water, producing 90 µmol/h of H2. The chemical structure was confirmed through XRD and XPS analyses, and the crystalline rhombohedral shape of CuFeO2 was confirmed using SEM and TEM analyses. With a bandgap of 1.35 ev, the prepared material displayed excellent optical properties. Electrochemical measurements for H2 gas generation were carried out using the CuFeO2/CuO/Cu photoelectrode, comparing the effect of light and dark and monochromatic wavelength light. The electrode exhibited significant enhancement in light compared to dark, with current density (Jph) values of −0.83 and −0.1 mA·cm−2, respectively. The monochromatic light also had a noticeable effect, with the Jph value increasing from −0.45 to −0.79 mA·cm−2 as the wavelength increased from 640 to 390 nm. This system is cheap and durable, making it a promising solution for hydrogen gas fuel generation in the industry.

This study describes the preparation and characterization of glass/poly-3-methyl aniline (P3MA)/PbS quantum dot (QD) optoelectronic photodetector to detect and sense the light in broad spectral regions of UV, Vis, and NIR. This work is carried out to solve the drawbacks of other studs that prepare detectors in just one or two optical regions. Previous studies have used high-priced techniques. The deposition of P3MA on the glass surface was carried out by in situ oxidation process. Then, this polymer film was used to assist the deposition of PbS-QD particles through the ionic adsorption deposition method. The latter was performed using four different concentrations of Pb(NO3)2 solution (0.01, 0.03, 0.05, and 0.07 M) to form four P3MA/PbS composites: I, II, III, and IV, respectively. The chemical structure, morphologies, and electrical and optical properties of these composites were determined using different analytical tools. The SEM confirmed the formation of spherical QD particles of PbS on the P3MA surface. The TEM analysis showed that the composite has an average size of 5 nm, with the interatomic distances of 0.4 nm. Furthermore, the optical band gap values were 1.53, 1.52, 1.50, and 1.51 eV, respectively. The optoelectronic device could detect and sense light from 390 to 636 nm under various optical wavelengths. The produced current density (Jph) values decreased from 0.029 mA.cm-2 at 390 nm to 0.022 mA.cm-2 at 500 nm and then increased until 0.024 mA.cm-2 at 636 nm. The light sensing was determined through the photoresponsivity (R) and detectivity (D) parameters, in which the photodetector has R and D values of 0.29 mA.cm-2 and 6.5×107 Jones, respectively. Finally, a simple mechanism was proposed to explain the light sensing through the prepared optoelectronic device. Soon, our team works on the industrial applications of this optoelectronic device in the industry field related to the great optoelectronic device technical properties and its low cost and easy preparation.

The dielectric characteristics of six culinary oils were measured over the frequency range of 0.01 Hz–100 kHz. The results showed that the dielectric constants of oils had the same frequency relationship (i.e., they decreased with increasing frequency). The dielectric constants at lower frequencies for olive oil A, olive oil B, sesame oil, Nigella sativa, sunflower oil, and corn oil are approximately 2.75, 2.5, 2.0, 1.75, 1.5, and 0.9. An FT-IR analysis showed that the spectral differences were very small, because most vegetable oils contain the same type of fatty acids. The model built using COMSOL Multiphysics for the potential and electric field distributions for different oils and used to calculate the dielectric constant was simulated under various conditions in the AC/DC module. The model results were compared with the experimental results, which showed satisfactory convergence between them. The experimental and model results obtained in this study could be useful for evaluating the edible oil quality.

The permeability and electrical resistivity of barium hexaferrite magnetic materials can be used in various products such as magnetic recording media, computers, electronic devices, materials for permanent magnets, and communication devices. This work focuses on the synthesis of rare earth lanthanum (La3+)-doped manganese in barium hexaferrite (Ba1−xLaxMnyFe12−yO19) (x = 0.02–0.10 and y = 0.02–0.10) prepared by using the coprecipitation method. The intensity peak is increased with increasing the concentration of lanthanum, which shows the enhancement in the degree of crystallinity and increase in the size of crystallite. The band gap energy decreased gradually with the increase of concentration of lanthanum. The micrographs observed that the material is basically made up of some rings or rods such as particles in pure La-Ma in barium hexaferrite. The agglomeration was observed because of heat behavior at 600°C or may be concentration effect. The structural studies are done using X-ray diffraction, UV, FT-IR, and SEM techniques.

This work reports on H2 fuel generation from sewage water using Cu/CuO nanoporous (NP) electrodes. This is a novel concept for converting contaminated water into H2 fuel. The preparation of Cu/CuO NP was achieved using a simple thermal combustion process of Cu metallic foil at 550 °C for 1 h. The Cu/CuO surface consists of island-like structures, with an inter-distance of 100 nm. Each island has a highly porous surface with a pore diameter of about 250 nm. X-ray diffraction (XRD) confirmed the formation of monoclinic Cu/CuO NP material with a crystallite size of 89 nm. The prepared Cu/CuO photoelectrode was applied for H2 generation from sewage water achieving an incident to photon conversion efficiency (IPCE) of 14.6%. Further, the effects of light intensity and wavelength on the photoelectrode performance were assessed. The current density (Jph) value increased from 2.17 to 4.7 mA·cm−2 upon raising the light power density from 50 to 100 mW·cm−2. Moreover, the enthalpy (ΔH*) and entropy (ΔS*) values of Cu/CuO electrode were determined as 9.519 KJ mol−1 and 180.4 JK−1·mol−1, respectively. The results obtained in the present study are very promising for solving the problem of energy in far regions by converting sewage water to H2 fuel.

This study provides H2 gas as a renewable energy source from sewage water splitting reaction using a PMT/Au photocathode. So, this study has a dual benefit for hydrogen generation; at the same time, it removes the contaminations of sewage water. The preparation of the PMT is carried out through the polymerization process from an acid medium. Then, the Au sputter was carried out using the sputter device under different times (1 and 2 min) for PMT/Au-1 min and PMT/Au-2min, respectively. The complete analyses confirm the chemical structure, such as XRD, FTIR, HNMR, SEM, and Vis-UV optical analyses. The prepared electrode PMT/Au is used for the hydrogen generation reaction using Na2S2O3 or sewage water as an electrolyte. The PMT crystalline size is 15 nm. The incident photon to current efficiency (IPCE) efficiency increases from 2.3 to 3.6% (at 390 nm), and the number of H2 moles increases from 8.4 to 33.1 mmol h−1 cm−2 for using Na2S2O3 and sewage water as electrolyte, respectively. Moreover, all the thermodynamic parameters, such as activation energy (Ea), enthalpy (ΔH*), and entropy (ΔS*), were calculated; additionally, a simple mechanism is mentioned for the water-splitting reaction.

The aim of this study is to investigate the structure–property relationship of the zirconium tungstate-reinforced casted A356 aluminum alloy. The reinforcement ceramic used was zirconium tungstate of the negative thermal coefficient type, which assists in the weldment of crack growth and enhances the fatigue life. The specimens used in this study were casted by stir casting method and prepared according to Compact Tension standard E-399, and microstructural, fatigue behavior, and mechanical properties were investigated systematically. Microstructural analysis showed reduction in porosity by the addition of ZrW2O8 particles. Fatigue results depict the increase in the fatigue life of aluminum reinforced ceramic as compared to the casted base aluminum alloy. Brinell hardness of ZrW2O8 reinforced alloy samples increased 7% as compared to the base aluminum alloy hardness value. Tensile strength also significantly improved from 176 MPa for the base A356 alloy to 198 MPa for the ZrW2O8 reinforced composite. Furthermore, addition of ZrW2O8 ceramic powder increased the fatigue life more than 50% of the base alloy. These results suggest that the ZrW2O8 reinforced A356 composites may be potential candidates for aerospace industry, military, transportation and in structural sites.

In the present work, we synthesized CoxZn1-xFe2O4 spinel ferrite nanoparticles (x= 0, 0.1, 0.2, 0.3 and 0.4) via the precipitation and hydrothermal-joint method. Structural parameters were cross-verified using X-ray powder diffraction (XRPD) and electron microscopy-based techniques. The magnetic parameters were determined by means of vibrating sample magnetometry. The as-synthesized CoxZn1-xFe2O4 nanoparticles exhibit high phase purity with a single-phase cubic spinel-type structure of Zn-ferrite. The microstructural parameters of the samples were estimated by XRD line profile analysis using the Williamson−Hall approach. The calculated grain sizes from XRPD analysis for the synthesized samples ranged from 8.3 to 11.4 nm. The electron microscopy analysis revealed that the constituents of all powder samples are spherical nanoparticles with proportions highly dependent on the Co doping ratio. The CoxZn1-xFe2O4 spinel ferrite system exhibits paramagnetic, superparamagnetic and weak ferromagnetic behavior at room temperature depending on the Co2+ doping ratio, while ferromagnetic ordering with a clear hysteresis loop is observed at low temperatures (5K). We concluded that replacing Zn2+ ions with Co2+ ions changes both the structural and magnetic properties of ZnFe2O4 nanoparticles.