Lead Zinc Oxide Research Articles

Simulation and Investigation of Si-Based Piezoelectric Micromachined Ultrasonic Transducer (PMUT) Performances

Micro-electromechanical system (MEMS) based piezoelectric ultrasonic transducers for acoustic imaging of the surroundings are known as piezoelectric micromachined ultrasonic transducers (PMUTs). This research proposes a structural design of the PMUT with four fixed-guided beams. The beam is subjected to lateral loads, with vectors that are perpendicular to the longitudinal axis. This project simulated Piezoelectric Micromachined Ultrasonic Transducer (PMUT) with three different material properties i.e. Aluminium Nitride (AlN), Lead zirconate titanate (PZT) and Zinc Oxide (ZnO). Based on the study, it was found that reducing the beam dimensions and increasing the plate size will result in the first mode frequency reduction from 1.33x107 Hz to 3.74x106 Hz. Other than that, it was found that AlN PMUT experienced the maximum deflection of 6.3413 to 6.3478 μm when the loads applied in the range of 50 to 200 μN/m2. When the piezoelectric material changed to PZT, we obtained the maximum deflections of 0.3771 to 0.3786 μm when the same loads range applied to the PMUT. As for the ZnO PMUT, the maximum deflections obtained were in between 0.1702 μm to 0.1772 μm with the loads are maintained as in the loads applied to the AlN and PZT. This study proved the significant impact of altering the structural dimensions and material properties of PMUTs on their operational characteristics, specifically the first mode frequency and deflection behavior.

Citrus limon peel-based biosynthesis: Lead oxide, zinc oxide, cadmium oxide, and copper oxide nano quantum dots for subtraction of anionic Actas Pink dye (AAPD)

ABSTRACT Adsorption is a highly effective method for wastewater quality adjustment, offering advantages such as low cost and availability of adsorbents. This study investigates the efficient removal of Anionic Actas Pink dye (AAPD), a major contributor to environmental pollution. Green adsorbents including lead oxide (PbO), zinc oxide (ZnO), cadmium oxide (CdO), and copper oxide (CuO) were synthesized via eco-friendly routes for AAPD removal. Maximum adsorption capacities (qe) were observed at pH 7 (PbO, ZnO, CdO) and pH 2 (CuO and native) with values of 83.83 mg/g at 100 ppm, 75.65 mg/g at 100 ppm, 70.50 mg/g 75 ppm, 61.21 mg/g at 150 ppm, and 52.69 mg/g at 150 ppm, respectively, using an adsorbent dose of 0.05 g/50 mL at temperature of 37°C, and 90 min contact time. Adsorption followed Langmuir isotherm for all adsorbents except native, with PbO also fitting Freundlich and Dubinin–Radushkevich isotherms. Kinetics adsorption data supported pseudo-second-order, while thermodynamic analysis indicated spontaneous and exothermic nature. Effects of electrolytes, surfactants, and desorption were also evaluated. Characterization through FTIR, SEM, and XRD confirmed the morphology and functional groups of these nano-quantum dots. Citrus limon peel-based biosynthesis offers sustainable, eco-friendly, and cost-effective alternatives, highlighting their potential for dye adsorption.

Chemical oxidation co-coagulation-flocculation for the flotation wastewater treatment of lead-zinc oxide ore from Lanping mine

The flotation wastewater produced by "lead preferred flotation-zinc flotation" all-open process with aids of mixed depressants and cationic-anionic collectors has a high turbidity and multitude of reagent contaminants, and fails to meet the discharge standards. This study objective is to remove fine solid particles and flotation reagents in this wastewater by chemical oxidation co-coagulation-flocculation process. Results of chemical oxidation tests indicate peroxymonosulfate (PMS) exhibits superior performance on decreasing COD, and the COD remarkably decreases to 71.8 mg·L<sup>-1</sup> with 100 mg·L<sup>-1</sup> PMS addition after 120 min. Moreover, the combined oxidation of radicals (SO<sub>4</sub><sup>•-</sup> and •OH) are responsible for degradation of flotation reagents (Na<sub>2</sub>S, DCCH, xanthates and amine) in the wastewater. Results of experimental factors confirm that the turbidity of wastewater decreases significantly from 124796 to 71.4 NTU, and the yield of water reaches above 90% with combined usage of lime (500 mg·L<sup>-1</sup>) and polyacrylamide (PAM, 50 mg·L<sup>-1</sup>). Besides, the contents of S, P, N, Zn Pb and Fe decrease, and meet the discharge standards. Results of zeta potential analysis suggest lime reduces the electrostatic repulsion between particles, and PAM plays a bridge link role between particles, accelerating the precipitation of suspended particle.

Efficient mechanochemical leaching of zinc from zinc oxide ores

A basket grinder was used as mechanochemical activation equipment to study low-grade lead–zinc oxide ores in the Lanping area, China and a mechanochemical leaching (MCL) process combining grinding with NaOH solution leaching was proposed for zinc leaching. The effects of leaching temperature, NaOH concentration, leaching time, liquid–solid ratio, and stirring speed on zinc leaching rate were investigated. Experimental results show that under the optimal conditions, the zinc leaching rate of MCL reaches 92.3%, which is 7.2% higher than that of conventional stirring leaching (CSL). And small difference in energy consumption is observed between the two processes, indicating the superiority of MCL. The strengthening mechanism of mechanochemical activation was investigated by analyzing the zinc phase of raw ore, and XRD, SEM−EDS, EPMA and particle size analyses were conducted on leaching residues from different processes under the optimal conditions.

Design and Optimization of Piezoelectric Pressure Sensor with AlN as piezo electric material for High-Temperature Application using COMSOL 5.3

Dynamic pressure sensors in contrast to static pressure sensors measure pressure changes in liquids or gases generated due to a blast, a propulsion or an explosion, where the temperature is normally high which is above 700°C[1]. Piezoelectric pressure sensors with their inherent advantage of direct transduction capability are drawing attention for high-temperature applications. Lead Zirconate Titanate (PZT) and Zinc Oxide (ZnO) are popular ferroelectric materials for Piezoelectric sensor applications. Aluminum Nitride (AlN) is a suitable candidate for high-temperature applications with its high melting point of 2673 K, the piezoelectric property remaining stable even up to 1423K, the energy band gap of 6.2eV, piezoelectric coefficient d33 of 7pC/N and pressure handling capacity up to 10 MPa. In this study, COMSOL Multiphysics 5.3 was used to analyse the pressure sensing capability of AlN film by optimizing the crystal orientation and the dimension of AlN in addition to studying suitability of using at high temperature. Also a comparison is done on the high temperature performance of pressure sensor using Silicon and Silicon Carbide as diaphragm.

Volatilization Kinetics of Zinc from the Flotation Products of Low-Grade Lead–Zinc Oxide Ore during Carbothermic Reduction

Zinc extraction from oxide ore has been paid more and more attention to due to the exhaustion of zinc sulfide ore resources. In this work, the volatilization kinetics of Zn from the flotation products of low-grade lead–zinc oxide ore during carbothermal reduction in the temperature range of 900–1300 °C were investigated. The phase transformation in briquettes during the reduction process was investigated by XRD and EPMA. The results showed that the transformation of ZnS by CaO may begin within the temperature range of 900–1050 °C, with the main occurrence observed in the range of 1050–1250 °C. The kinetics behavior of Zn volatilization was associated with the phase transformation. The volatilization of Zn was controlled by the interfacial chemical reaction within 900–1150 °C. As the reaction proceeded, the generation of the product layers (CaS, FeS and new slag phase) impeded the internal diffusion of Zn, CO and CO2. At this time, internal diffusion served as the rate-controlling step for Zn volatilization in the range of 1150–1300 °C. Hence, a staged kinetics model of Zn volatilization during carbothermal reduction in the form of carbon-bearing briquettes was established, and the apparent rate constants (k(T)) and activation energies (Ea) were obtained. This work provides a scientific basis for the flotation products treatment by carbothermal reduction and is of great significance in improving the sustainability of resources in the zinc smelting industry.

Piezo‐Phototronic Effect‐Induced Self‐Powered Broadband Photodetectors using Environmentally Stable α‐CsPbI3 Perovskite Nanocrystals

AbstractUtilizing the remarkably high light absorption and long carrier diffusion length of inorganic perovskites, superior performance self‐powered broadband photodetectors using the vertical heterojunction of cesium lead iodide (CsPbI3) nanocrystals (NCs) and zinc oxide (ZnO) films on a flexible platform are reported. Here, the pure cubic or α‐phase of as‐synthesized CsPbI3 NCs facilitate the novelty of the present work in terms of their enhanced structural stability suitable for optical applications. The α‐CsPbI3/ZnO device exhibits superior performance with photoresponsivity of ≈8.2 AW−1, ON/OFF ratio of ≈2.4 × 104, and specific detectivity up to ≈1.4 × 1012 Jones. Furthermore, the piezo‐phototronic effect of ZnO has been exploited to enhance the device performance by utilizing the compressive strain‐induced piezoelectric charges for modulating the generation, separation, and transportation of charge carriers. By introducing an approximate −0.042% compressive strain in the hybrid heterostructure, the enhancement of photocurrent, spectral responsivity, and specific detectivity of the detector by ≈619%, ≈536%, and ≈506%, respectively, under visible light illumination has been successfully achieved. This work not only presents an inventive method for improving the performance of perovskite photodetectors through interface engineering, but it also provides a thorough understanding of the piezo‐phototronic effect on optoelectronic devices.

Heterojunction Infrared Photodiodes With High Dynamic Range Based on Lead Sulfide Quantum Dot and Zinc Oxide Nanomembrane

Heterojunction Infrared Photodiodes With High Dynamic Range Based on Lead Sulfide Quantum Dot and Zinc Oxide Nanomembrane

Tuning optical properties of zinc oxide and methyl ammonium lead iodide by ultrasound assisted method

In the last few decades, ultrasound assisted methods have emerged as environmentally friendly and cost-effective technologies for chemical synthesis. It provides higher yields under mild reaction conditions compared to traditional methods. Methyl ammonium lead iodide and zinc oxide have gained importance in academic as well as industrial research due to their unique optoelectronic properties. Ultrasonication induces changes in the material properties due to acoustic cavitation in the solvent based synthetic approach. As a proof of the concept, the present work includes the study of impact of ultrasound treatment on optical and morphological properties of the title compounds. All the products were characterized by using various analytical techniques such as DRUV, PL, FTIR, XRD and FE-SEM-EDS. XRD reveals the formation of pure phase of the products. Optical properties are analyzed using DRUV and PL spectroscopy and Tauc‘s plot. Surface modification is observed in both the products (ZnO and methyl ammonium lead iodide) synthesized by sono assisted method inducing changes in the optical band gap. Interestingly, ZnO shows increase in particle size because of ultrasound impact leading to decrease in photocatalytic activity.

Dynamics of interfacial carriers and negative photoconductance in CH3NH3PbBr3-ZnO heterostructure

Understanding the interfacial charge transfer process and its dynamical mechanism is crucial to design efficient photoelectric devices. Methylammonium lead halide perovskite and zinc oxide (ZnO) have been demonstrated as promising candidates for excellent solar cells and photodetectors. However, the carrier transport process has not yet been fully explored on the perovskite surface and the perovskite/ZnO interface. Herein, a CH3NH3PbBr3-ZnO heterojunction was constructed as a quasi-phototransistor, where an apparent negative photoconductance was observed under illumination. Based on electrical and optical characterization, the photogenerated carrier transfer dynamics at CH3NH3PbBr3, ZnO, and their interface were investigated in detail. It can be assigned that the photogenerated electrons transfer toward the CH3NH3PbBr3 surface and the holes transfer to interior, so that the light-induced built-in electric field change would serve as the photogate to control the current flowing in the CH3NH3PbBr3-ZnO channel. These results provide clear images on the charge diffusion and drift process in the CH3NH3PbBr3-ZnO heterostructure. The study on the dynamics of negative photoconductivity of CH3NH3PbBr3-ZnO has great value for understanding the carrier transport properties and constructing perovskite heterostructure memory and optical switching devices.

Structure and electrochemical behaviour of composite Pb-nano ZnO in sulfuric acid solution for different temperature

Lead is one of the important materials used as an electrode for batter application. With a good performance at the lowest price possible, using lead as an active material for lead-acid battery still high even though the fact that lead waste is very dangerous for the environment. Lead must be optimized to reduce lead waste with adding new material to the lead for the electrode. For this research lead and nano zinc oxide became a composite Pb-Nano ZnO and this composite tested into sulfuric acid solution with various solution temperature 10°C, 25°C, and 40°C. The structure and electrochemical behaviour were analysed with X-Ray Diffraction (XRD) and Potentiostat (LSV and CV) respectively. Detected phase from the spectrum shows lead phase with cubic FCC crystal structure. Linear Sweep Voltammetry and Cyclic Voltammetry test used to see is the composite can be used as an electrode for a battery and is the performance different than lead electrode. The result shows that the composite is electrochemically reversible and corrosion rate decrease when nano ZnO added with lowest corrosion rate 0.011852 mm/year in ZnO 20% wt composition on temperature variation 10°C.

Reactive modification of zinc oxide with methylammonium iodide boosts the operational stability of perovskite solar cells

Low operational stability of perovskite solar cells represents a major obstacle for practical implementation of this technology. In that context, ZnO was considered as a promising electron transport material with suppressed oxidizing properties as compared to SnO2 and TiO2. However, the first studies revealed the chemical instability of the interface between lead halide perovskites and zinc oxide, whereas the underlying reasons are still under active debates. Still, the interfacial instability issues made ZnO a largely overlooked electron transport layer despite its excellent optoelectronic properties. This study presents a novel approach to the zinc oxide surface modification with methylammonium iodide that suppresses further reactions with the adjacent perovskite absorber layer. Consequently, the solar cells based on CH3NH3PbI3 exhibited largely improved thermal stability. Furthermore, the application of Cs0.12[HC(NH2)2]0.88PbI3 as absorber material in devices with the modified ZnO electron transport layer resulted in 82% retention of the initial efficiency after aging for 2100 h at 50 mW cm−2 and 65 °C. On the contrary, the reference cells fabricated with the pristine non-modified ZnO degraded completely under the same conditions. We attribute the revealed stabilization effect of the methylammonium iodide treatment to passivation of the reactive ZnO surface and inhibiting the parasitic interfacial chemistry leading to the lead iodide formation. To our best knowledge, here we have demonstrated the highest operational stability for the perovskite cells when using ZnO-based ETL.

Spectral studies of highly Dy3+ doped PbO–ZnO–B2O3–P2O5 glasses

Phosphate glasses having composition 50P2O5–10B2O3–20ZnO–20PbO–xDy2O3 where x = 0.04, 0.18, 0.36, 1.10, 1.80, and 3.60 mol% were prepared by melt quenching technique. The FTIR spectra reveal the different structural groups of the phosphate glass induced by modifiers such as lead oxide and zinc oxide, which could be explained in terms of the distortion of PO4 tetrahedra and the network depolymerization process. The photoluminescence spectrum shows three prominent emission bands centered at 475, 586, and 675 nm corresponds to the 4F9/2 → 6HJ (J = 11/2, 13/2, 15/2) transitions, respectively, and the intensity ratio of yellow to blue emissions are enhanced as the concentration of Dy3+ ions increased up to 3.60 mol%. The 4F9/2 excited state's lifetime decreases by continuously increasing the amount of the trivalent lanthanide ion due to probable energy transfer between neighboring ions. The chromaticity diagram is studied as the rare-earth ion concentration, which gives the nearest condition to the white color at 0.36 mol% of the Dy3+ ions.

Multisystemic damage to mitochondrial ultrastucture as an integral measure of the comparative in vivo cytotoxicity of metallic nanoparticles

Vehicles emissions of nanoparticles is a one of the major threat to humans in the modern conditions. Subchronic intoxication was induced in outbred male rats by repeated intraperitoneal injections of lead oxide, zinc oxide and copper oxide nanoparticles separately, or in three binary combinations, or in the full triple combination. Based on electron microscopy results, this paper considers the usefulness, feasibility and informativity of an approach based on a generalized semi-quantitative assessment of toxic damage to mitochondria in various organs using partial or complete destruction of cristae as an index of damage. The adequacy of such assessment is confirmed by its consistency with the previously published data on the relative and combined toxicity of nanoparticles of the above species and high protective efficacy of a complex of bioprotectors estimated by a great number of functional and optical-microscopy morphometric indices.

Colour and Ink Characterization of Ottoman Diplomatic Documents Dating from the 13th to the 20th Century

Abstract This study investigates the colours and inks used in diplomatic documents of the Ottoman Empire dating from the 13th to the 20th century. Elemental and spectroscopic analyses were carried out on more than 150 documents using μ-XRF, Raman and FTIR spectroscopy; 10 documents were selected representatively for each century. In addition to the characterization of colour and ink, their use and distribution through the centuries is discussed. Analysis showed the presence of minium, vermilion, red ochre and cochineal (red pigments); lapis lazuli (ultramarine blue), azurite (blue verditer), Prussian blue and smalt (blue pigments); malachite and green earth (green pigments); massicot and yellow lead (yellow respectively orange pigments) and basic lead carbonate and zinc oxide (white pigments). All illuminations were ornamented with gold to demonstrate the power of the Empire and the Emperor. Texts were written in iron gall- and carbon-based black ink (carbon black/soot), cochineal (red) ink and gold.

Simultaneous study of exciton dissociation and charge transport in a light harvesting assembly: Lead selenide nanocrystal/zinc oxide interface

Simultaneous study of exciton dissociation between lead selenide (PbSe) and zinc oxide (ZnO) nanocrystals, and charge transport in the electron acceptor (ZnO) was carried out using the field effect transistor (FET) arrangement in which a bi-layer of PbSe and ZnO is formed onto the SiO2 substrate. Using multiple potential probes between the source and drain electrodes, change in the electrical conductance in the ZnO, proportional to exciton dissociation at the electron donor/acceptor (PbSe/ZnO) interface, was measured excluding the Au/ZnO contact resistance. Surface ligand capping dependent exciton dissociation at the ethanedithiol-treated PbSe/ZnO interface was compared with the biphenyl-4,4′-dithiol-treated PbSe/ZnO interface using the FET geometry, demonstrating that a shorter ligand is more favorable to exciton dissociation. From the light intensity dependent conductivity change in the ZnO layer, the origin of carrier recombination is discussed.

Synthesis, Direct Formation under High Pressure, Structure, and Electronic Properties of LiNbO3-type Oxide PbZnO3.

A novel LiNbO3-type (LN-type) lead zinc oxide, PbZnO3, was successfully synthesized under high pressure and temperature. Rietveld structure refinement using synchrotron powder X-ray diffraction (XRD) data demonstrated that LN-type PbZnO3 crystallized into a trigonal structure with a polar space group (R3c). The bond valence sum estimated from the interatomic distances indicated that the sample possesses a Pb(4+)Zn(2+)O3 valence state. Polarization could evolve as a result of the repulsion between constituent cations because PbZnO3 does not contain a stereochemical 6s(2) cation or a Jahn-Teller active d(0) cation. Distortion of ZnO6 octahedra resulting from cation shift is comparable with that of d(0) TiO6 in ZnTiO3 and MnTiO3 with LN-type oxides, which leads to stabilization of the polar structure. PbZnO3 exhibited metallic behavior and temperature-independent diamagnetic character. In situ XRD measurement revealed that the formation of LN-type PbZnO3 occurred directly without the formation of a perovskite phase, which is unusual among LN-type materials obtained by high-pressure synthesis.

Study on Flotation of Lead-Zinc Oxide Ore from Yunnan

With regard to a deep-extend oxidized refractory lead-zinc ore from Yunnan province, containing 4.55% Pb and 17.09% Zn, a test study was carried out. By adopting single-stage roughing, single-stage scavenging, two-stage cleaning in the flotation of lead oxide ores, and single-stage cleaning, single-stage cleaning in the reverse flotation of zinc oxide ores, bulk concentrate of lead and zinc containing 36.60% Pb, 19.63% Zn with the Pb recovery of 82.45%, zinc concentrate containing 36.52% Zn, 0.44%Pb with the Zn recovery of 73.18% were obtained in the closed circuit experiment.

Experimental Research of Mineral Processing on a Certain Lead-Zinc Oxidize Ore

A certain multi-metallic lead-zinc oxide ore contains 1.09%Pb，8.39%Zn． The oxide rate of lead and zinc is 96.34% and 98.15% respectively．In order to recover valuable minerals from the oxide ore comprehensively, the authors adopted priority flotation processing in this experimental research. At last, the lead concentrate with Pb grade of 27.41% and the zinc concentrate with Zn grade of 24.14 % were respectively achieved. The overall recovery of lead was 93.66%，and the overall recovery of zinc was 90.74%.

Impact of screen printing silver paste components on the space charge region recombination losses of industrial silicon solar cells

An approved measurement method for evaluating space charge region recombination (SCR-recombination) induced by the screen printed front side metallization is applied for industrial solar cells with aluminum back surface field (Al-BSF) on monocrystalline Czochralski silicon (Cz-Si). The H-patterned base grid of all processed solar cells is screen printed with a commercially available front side silver paste, ensuring sufficiently good contacting and therefore good electrical performance of the solar cells. Additionally, irregular contact fingers are realized between the regular contact fingers of the base grid by applying different screen printing layouts with commercially available front side pastes to increase the front side metallization fraction linearly as well as by applying various test pastes for the layout with the highest metallization fraction. Well-known components of glass frits as lead oxide, zinc oxide, bismuth oxide and boron oxide can affect SCR-recombination. Therefore we fabricated test pastes with these specific paste/glass frit components. By applying this test structure, a comparable qualitative evaluation of SCR-recombination with respect to the specific paste component is demonstrated. Quantitative evaluations regarding the electrical performance of the solar cells as well as related microstructural investigations are presented.