Concentration Of Copper Oxide Research Articles

Eco-friendly synthesis, characterization, and properties of copper oxide nanoparticles in cashew gum/polypyrrole blend for energy storage applications

Conducting biopolymer blend nanocomposites of cashew gum (CG) and polypyrrole (PPy), with varying concentrations of copper oxide (CuO) nanoparticles were synthesized through an in-situ polymerization method using water as a sustainable solvent. The formation of blend nanocomposites was characterized using UV–visible (UV–vis) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). UV spectroscopy revealed a significant reduction in absorption intensity with the addition of CuO, indicating enhanced optical properties. FT-IR and XRD analysis confirmed the successful incorporation of CuO into the CG/PPy blend. FE-SEM images revealed the uniform distribution of nanoparticles throughout the biopolymer blend, particularly in the 7 wt% sample. TGA and DSC results demonstrated a significant enhancement in thermal stability, increasing from 352 °C to 412 °C and a rise in the glass transition temperature from 89 °C to 106 °C in the blend nanocomposites. The dielectric constant, dielectric loss, impedance, Nyquist plot, electrical conductivity, and electric modulus were extensively examined at different temperatures and frequencies. The dielectric constant of the CG/PPy blend increased from 2720 to 92,950 with the addition of 7 wt% CuO, measured at 100 Hz. The improved glass transition temperature, thermal stability, and superior electrical properties imply potential usage of the developed nanocomposite in nanoelectronics and energy storage applications.

CuO vs. AgO: A comparative study of cathode catalysts for boosting oxygen reduction in microbial desalination cells

Microbial Desalination Cell (MDC) is an innovative approach for water desalination that concurrently produces energy through the process of substrate oxidation. The primary issue of the technique is its limited power on capabilities during the oxygen reduction reaction (ORR). While the depletion of oxygen is a significant process in electrochemical energy conversion, its slow kinetics hinder its utilization in MDCs. One potential resolution to this problem is the utilization of a cathode catalyst with a high level of activity, which effectively enhances the rate of ORR. Different concentrations of copper oxide (CuO) nanoparticles (NPs) were used to investigate the behavior of ORR and its impact on the performance of the MDC. The optimal concentration of silver oxide (AgO) NPs was utilized to conduct a comparative analysis of both types of NPs. The size of CuO NPs and AgO NPs was found to be 65nm and 55nm respectively by material characterization studies. The power density achieved in the absence of the catalyst was 1.1W/m3, and this value increased to 4.9W/m3 with the incorporation of 3mg/cm2 AgO. The use of a catalyst loading of 3mg/cm2 has been determined to be efficacious in enhancing the desalination rate in MDC. The electrochemical investigations conducted also showed an improvement in the electrocatalytic behavior of cathodic kinetics while operating under these specific afterward. Therefore, the utilization of AgO catalyst exhibits potential as a viable option for the expansion of MDC processes, thereby contributing to the achievement of sustainable development objectives.

Correlation between the micro-shot peening coverage and surface microstructural evolution and fluoride-induced corrosion behavior in Monel 400 alloy

This study examines the influence of micro-shot peening (MSP) on Monel 400 alloy, focusing on surface microstructural evolution and fluoride-induced corrosion behavior compared to its solution annealed (SAed) counterpart. MSP treatments were conducted at various surface coverages (100%, 200%, 500%, 1000%, 1500%, and 2000%). Characterization encompassed microhardness, surface roughness, grazing incidence x-ray diffraction (GI-XRD), field emission scanning electron microscopy (FE-SEM) with electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). With increasing the MSP coverage to 2000%, the surface crystallite size decreased from approximately ∼30 µm in the SAed sample to 60 nm. TEM analysis emphasized dislocation slip and formation of dislocation structures as the primary mechanisms for the grain refinement. However, the 2000% coverage exhibited microcrack formation, compromising its hydrofluoric (HF) corrosion resistance. Electrochemical tests revealed severe localized corrosion in all MSP-treated samples except the 1500% coverage, which exhibited a minimum passive current density of 0.2–1.0 µA/cm2. Inductively coupled plasma optical emission spectroscopy (ICP-OES) of immersion solutions showed lower copper and nickel ion concentrations (<150 ppm) in the 1500% MSP-treated sample, indicating its enhanced corrosion resistance. X-ray photoelectron spectroscopy (XPS) identified NiO, NiF2, CuO, CuF2, and Cu(OH)2 phases in SAed and 1500% MSPed samples, with a higher concentration of copper oxide (CuO) in the corrosion film of the 1500% MSP-treated sample, contributing to its superior corrosion resistance.

Zinc and copper toxicity in basil (Ocimum basilicum L.) seedlings: Role of melatonin in mitigating stress

The effects of melatonin (MT) on the growth and antioxidant responses of basil (Ocimum basilicum L.) exposed to copper and zinc excess stress are investigated. For this purpose, seedlings were exposed to different concentrations of copper oxide (0, 50 and 150 µM), zinc oxide (0, 50 and 100 µM) and melatonin (0 and 100 µM) for 14 days. Growth and biochemical parameters, the activity of some antioxidant enzymes, and phenylalanine ammonia lyase (PAL) and some of the main nutritional elements in the shoot and root of seedlings were measured. The results of this study showed that the excess of copper (Cu 50 and 150 µM) and zinc (Zn 50 and 100 µM) causes a decrease in growth, and a higher oxidative stress indicator such as hydrogen peroxide and malondialdehyde (MDA) content. The homeostasis balance of mineral nutrition of basil seedlings was also disrupted under copper and zinc stress. Melatonin treatment in Cu, Zn stressed seedlings improved growth parameters by reducing the levels of hydrogen peroxide (H2O2) and malondialdehyde (MDA) and increasing the activity of PAL and antioxidant enzymes. Melatonin also regulated the distribution of minerals in basil seedlings under Cu and Zn stress conditions. The results of this research showed that MT can improve the tolerance of basil seedlings against copper and zinc stress by modulate growth and antioxidant responses and regulating mineral nutrition.

Analysis of the Effect of an Absorbent Plate Coated with Cuo Nanoparticles on Single Slope Solar Distillation

Water is one of the basic needs that must be fulfilled by living things, especially humans, starting from daily activities such as cooking, washing, and so on. It is possible that the water source has been contaminated with other contaminants. Various methods are used to obtain proper water, one of which is the solar distillation method. Solar distillation is a method of purifying water that has not been widely used due to its low productivity. Copper Oxide Nanoparticles (CuO) were chosen as the material to be added to the black paint on the bottom of the distillation basin, this was done to increase its productivity. Experiments were carried out with concentrations of copper oxide (CuO) nanoparticles by weight of 10%, 15%, and 20%. It was found that adding nanoparticles to the paint increased the heat transfer rate and water temperature. The results obtained showed that CuO nanoparticles increased efficiency by 6.66%, 16.91% and 27.93% compared to conventional distillation apparatus at concentrations of heavy fractions of 10%, 15% and 20%, respectively. From this modification of the tool, the highest condensate mass was obtained at the concentration of the heavy fraction of 20% CuO nanoparticles with an average of 806 ml/day, while the other variations obtained an average condensate mass of 512 ml/day and 655 ml/day at the concentration of the heavy fraction respectively. 10% and 15% respectively.

Experimental Study and Thermodynamic Modelling of Equilibrium Distributions of Ni, Sn and Zn Between Slag and Black Copper for E-Scrap Recycling Applications

The recycling of waste electronic and electrical equipment (WEEE) and other secondary copper-containing materials through the "black copper" process relies on the selective distribution of metals among the gas, slag, and copper-rich liquid phase. This distribution is controlled by the effective oxidation/reduction potential, often expressed in terms of oxygen partial pressure. Separation of Ni and Sn presents a certain challenge in recycling though black copper route due to similar distribution coefficients over a wide range of oxygen partial pressures and possibly can be improved by optimizing the slag chemistry. This study provides experimental information on the distribution of Ni, Sn, and Zn between fayalite slags or calcium ferrite slags and copper-rich metal at 1250°C. The study uses high-temperature equilibration, quenching, and electron probe X-ray microanalysis (EPMA) techniques along with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for selected measurements of low concentrations. The oxygen partial pressure is controlled by the CO/CO2/Ar gas flow or by measuring the concentration of copper oxide in the slag. The effect of slag composition in terms of Fe/SiO2 or Fe/CaO ratio is studied by using different holding materials, such as silica (SiO2) ampoule, solid spinel (Fe3O4), wüstite (FeO), or dicalcium ferrite (Ca2Fe2O5). The experimental results are compared with literature data and used to optimize thermodynamic models for FactSage® software. The results demonstrate an opportunity for more effective separation of Ni and Sn using at oxidizing stage by using calcium ferrite slag promoting the formation of Sn4+.

Performance analysis of vapor compression refrigeration system using varying concentrations of copper oxide (CuO)/mineral oil (MO) based nanosuspension

The nanofluid is being utilized for more than a decade to improve the theocentric properties of various thermal systems. In the presented work, the copper oxide (CuO) nanoparticle suspension is utilized to improve the performance of the vapor compression refrigeration system. Mineral oil is utilized as the base fluid for the synthesis of CuO-based nanosuspension. The nanosuspension is synthesized with a concentration of 0.02 wt%, 0.04 wt% and 0.06 wt%. For the refrigeration system, R600a refrigerant is used. The experimental analysis is carried out in two phases. In the first phase of the experimental analysis, the CuO-based nanosuspension is synthesized and the thermophysical properties such as thermal conductivity, specific heat, and density are evaluated. In the second phase, the synthesized nanosuspension has been incorporated into the refrigeration system. The performance parameters such as COP, power consumption, and pull-down time are investigated using R600a/MO/CuO-based nanosuspension. From the first phase of the experimentation, it is concluded the CuO nanoparticle significantly enhances the thermophysical properties of the pure mineral. A significant gain in thermal conductivity and density is noted along with a reduction in the specific heat of the pure mineral oil. Similarly, from the second phase of the experimentation, it observed that the higher average gain in the COP by 30.2%, reduction of power consumption by 12.53%, and reduction in pull down time is noted by using 0.06 wt% of CuO-MO-based nanosuspension.

Comparative Study of Physicochemical Characteristics and Catalytic Activity of Copper Oxide over Synthetic Silicon Oxide and Silicon Oxide from Rice Husk in Non-Oxidative Dehydrogenation of Ethanol

The article presents the results of comparative research on the physicochemical characteristics and catalytic activity of copper oxide supported on synthetic SiO2 and SiO2 (RH) from rice husk. SiO2 (RH) is more hydrophobic compared to SiO2, which leads to the concentration of copper oxide on its surface in the form of a “crust”, which is very important in the synthesis of low-percentage catalysts. According to SEM, XRD, and TPR-H2, the use of SiO2 (RH) as a carrier leads to an increase in the dispersion of copper oxide particles, which is the active center of ethanol dehydrogenation.

Performance and exergy analysis of solar-operated vacuum fan and external condenser integrated double-slope solar still using various nanofluids.

Productivity, distillate exergy, and energy efficiency of the conventional passive single-basin double-slope solar still is minimum, due to low evaporation and condensation rate. This research article attempts to increase the production rate, distillate exergy, and energy efficiency of the single-basin glasswool-insulated double-slope solar still by attaching novel solar-operated vacuum fan, external condenser and adding 0.1% volume concentration of copper oxide, aluminium oxide, and zinc oxide nanofluid. Inclusion of vacuum fan and external condenser enhances the production rate in the modified solar still. It is evident that as the vacuum fan exhales the vapour in the basin, the temperature of water in the basin and transparent glass are reduced significantly and so the vaporization amount increases considerably. It makes that a large amount of vapour is extracted by the vacuum fan and allowed to pass though the condenser, and therefore, the entire condensate of the solar still is increased significantly. To attain a comparative study, conventional and modified double-slope solar still of identical dimensions were developed utilizing aluminium and an experimental investigation carried out during the peak of summer. The inclusion of solar-operated vacuum fan and external condenser in the modified glasswool insulated double-slope solar still enhances the maximum energy efficiency, exergy efficiency, and cumulative production by 28.37%, 78.60%, and 64.29% due to enhancement in the evaporation rate of liquid in the solar still basin. Also, the addition of 0.1% volume concentration of copper oxide, aluminium oxide, and zinc oxide nanofluid in the conventional double-slope solar still possess the maximum increase in the energy efficiency and exergy efficiency by 20.96%, 18.01%, 10.76% and 52.53%, 38.52%, 30.35% as compared to conventional solar still without nanofluid. It is primarily due to increase in the thermal conductivity and radiative property of nanofluid. The result also signifies that the addition of 0.1% volume concentration of copper oxide, aluminium oxide, and zinc oxide nanofluid in the modified double-slope solar still possess the maximum enhancement in the energy efficiency and exergy efficiency by 21.33%, 19.36%, 17.03% and 50.11%, 36.82%, 23.75% as compared to modified solar still without nanofluid. Combined effect of using solar-operated vacuum fan, water cooled condenser, and 0.1% volume concentration of copper oxide, aluminium oxide, and zinc oxide nanofluid in the double-slope solar still enhances the maximum production rate and cumulative production by 59.26%, 55.56%, 51.85% and 96.43%, 82.14%, 75% as compared to conventional double-slope solar still. Among the three different nanofluids, the copper oxide nanofluid produced the highest cumulative production, energy efficiency, and exergy efficiency.

Preliminary study of the photodegradation of dyes using amorphous films of ZnO-CuO obtained by photochemical deposition in solid phase.

Here, we propose an original method of photochemical deposition for the synthesis of metal oxides from coordination complexes sensitive to UV light. The method consists of the synthesis of zinc oxide amorphous films doped with different concentrations of copper oxide followed by annealing at 600°C. The photo-reactivity of the samples was evaluated by the decrease of the FT-IR spectroscopy bands. The films were analyzed by scanning electron microscopy (SEM-EDX) and X-ray diffraction (XRD) to study their morphology and structures, respectively. The results show an amorphous characteristic in the photo-deposits. The optical properties show a gradual decrease of both the optical band gap and the luminescent emissions of the ZnO photo-deposits when CuO doping increases. Both properties allow a shift in absorption towards the visible and a decrease in the rate of recombination of charge carriers. The photocatalytic activity was analyzed using methyl orange and methylene blue as pollutants under a lamp that emulates solar energy. The results show that the photocatalytic activity is favored by the insertion of CuO; 46.6 and 93.0% efficiency in the photodegradation of methyl orange and methylene blue, respectively, were reached at 1.0mol % of CuO with respect to pure ZnO. These differences in degradation efficiency respond to the chemical stability of the dyes. Finally, the use of appropriate scavengers suggests an oxidative route in the dye degradation mechanism.

Simulation for converting of two phase of water in complex container with finite element approach

In this work, the freezing process has been expedited with elevating the concentration of nanoparticles and increasing their shape factor. The driving force of solidification is conduction mode and it is reasonable proposition to neglect the buoyancy force in deriving the mathematical model. Due to absence of velocity term, only temperature equation with involve of unsteady source term of phase changing have been involved. For better visual presentation of speed of freezing, solid front has been portrayed for various cases. The impacts of shape factor and volume concentration of copper oxide have been demonstrated in outputs. The patterns of grid demonstrate the adaptive grid and the code were verified according to previous publication. With growth of concentration of CuO, the period declines around 11.72% which is associated with elevation of conductivity. Moreover, outputs revealed that with imposing higher shape factor, the process finished in lower time about 5.96%.

Mechanical and radiation shielding properties of CuO doped TeO2–B2O3 glass system

A series of borotellurite glass system doped with copper oxide was synthesized using the method of melt quenching. The density of the glass decreases whereas its molar volume increases in respect to copper oxide concentration. The amorphous nature of prepared glasses was proven with the utilisation of XRD spectra. Meanwhile, the glass samples' elastic properties are determined from the measurement of longitudinal and shear velocities using ultrasonic technique. The longitudinal modulus, shear modulus, bulk modulus and Young's modulus has shown an irregular trend that fluctuates within certain limits. Moreover, the FLUKA Monte Carlo code is implemented to determine the shielding features at gamma energy of 0.3565, 0.6616, 0.8348 and 1.3325 MeV. Linear attenuation coefficients acquired from FLUKA and XCOM are found to be in good agreement with relative difference <1%. The glass sample B2O3TeO2CuO1 (with highest percentage of TeO2) is found to be the best shielding glass material in this study.

Electrospun PVA/CuONPs/Bitter Gourd Nanofibers with Improved Cytocompatibility and Antibacterial Properties: Application as Antibacterial Wound Dressing.

Antibacterial and cyto-compatible tricomponent composite electrospun nanofibers comprised of polyvinyl alcohol (PVA), copper II oxide nanoparticles (CuONPs), and Momordica charantia (bitter gourd, MC) extract were examined for their potential application as an effective wound dressing. Metallic nanoparticles have a wide range of applications in biomedical engineering because of their excellent antibacterial properties; however, metallic NPs have some toxic effects as well. The green synthesis of nanoparticles is undergoing development with the goal of avoiding toxicity. The aim of adding Momordica charantia extract was to reduce the toxic effects of copper oxide nanoparticles as well as to impart antioxidant properties to electrospun nanofibers. Weight ratios of PVA and MC extract were kept constant while the concentration of copper oxide was optimized to obtain good antibacterial properties with reduced toxicity. Samples were characterized for their morphological properties, chemical interactions, crystalline structures, elemental analyses, antibacterial activity, cell adhesion, and toxicity. All samples were found to have uniform morphology without any bead formation, while an increase in diameters was observed as the CuO concentration was increased in nanofibers. All samples exhibited antibacterial properties; however, the sample with CuO concentration of 0.6% exhibited better antibacterial activity. It was also observed that nanofibrous mats exhibited excellent cytocompatibility with fibroblast (NIH3T3) cells. The mechanical properties of nanofibers were slightly improved due to the addition of nanoparticles. By considering the excellent results of nanofibrous mats, they can therefore be recommended for wound dressing applications.

Thermal performance enhancement of nanofluids based parabolic trough solar collector (NPTSC) for sustainable environment

Due to rapid industrialization and urbanization, upward rise in carbon emissions in the atmosphere, and depletion of fossil fuel and gas reserves have forced to find alternative renewable energy resources, where solar energy is one of the most promising source. Parabolic trough solar collectors (PTCs) can effectively transfer high temperature in the tube of receiver upto 400 °C. In this study, Computational Fluid Dynamics (CFD) analysis is used to analyse the effect of multiple working fluids on efficiency of the PTC. Two different types of nanofluids used for analyising the thermal efficiency of PTC through CFD simulations, are Alumina and Copper-oxide nanofluids. The concentration of Copper Oxide and Alumina was kept to 0.01% in the nanofluids. The efficiency for PTC is calculated at two different mass flow rates i.e., 0.0112 Kg/s and 0.0224 Kg/s. The highest efficiency is 13.01 and 13.1% using Al2O3 as nanofluids at 0.0112 Kg/s and 0.0224 Kg/s flow rates, while CuO has an efficiency of 13.92% and 14.79% for these flow rates. The behaviour of absorber tube material on temperature distribution for steel, copper and aluminum as absorber tube material was also investigated. Changing the material from steel to copper and aluminum increased the outlet temperature of the fluid. The maximum output temperature was achieved for copper is 311 K while steel and aluminum showed lower temperature of 307 K and 308 K of the fluid at the outlet. Furthermore, the impact of the receiver tube’s length on the working fluid’s temperature is also studied. Copper Oxide nanofluid has higher temperature at the outlet for both mass flow rates as compared to alumina nanofluid. Accordingly, a comparison was made for the CFD results with the experimental findings from literature. The nanofluids based PTCs system is promising method for the sustainable environment applications.

Impact and Assessment of Engineered Metallic Nano-oxide on the Growth and Development of Gossypium hirsutum L.

Background: Metallic nano-oxide has been influenced the environment in the past two decades. Their consequences are dreadfully uncertain. The increased graph of their interference suggested many extensive studies in various fields of the environment. The Gossypium hirsutum one of the prime harvest plants in India has been chosen for studying the impacts of metallic nano-oxide on their morphological characters as well as their fresh shoot and root weights. Methods: Study has been done in July 2020 as a randomized triplet. The need for the study was fulfilled by the four different metallic nano-oxides with their five specific concentrations. The metallic nano-oxides were titanium oxide, silver oxide, copper oxide and zinc oxide. The five concentrations 00 ppm, 40 ppm, 60 ppm, 80 ppm and 100 ppm were taken from each one of metallic nano-oxide. Result: The zinc oxides treatment gave noteworthy positive growth and development in Gossypium hirsutum from germination to the blossoming time. Conversely, the concentrations of silver oxides were found little toxic for the growth of species. The copper and titanium oxides indicated little diversity in their growth patterns. The germination studies calculated best with titanium oxide treatment. The 80ppm concentration of copper oxide also reported better results at germination in comparison to control.

Structure, Morphology and Optical Properties of SnO2 Nanoparticle Synthesized via Ultrasonic Spray Pyrolysis Technique: Effect of CuO Doping Concentration

Tin oxide (SnO2) and doped with various concentrations of copper oxide (CuO) of (3, 5, and 7%) nanoparticles were synthesized via a simple, cost-effective, and nontoxic ultrasonic spray pyrolysis technique on glass substrates. Crystalline structure, surface morphology of the SnO2 pure and SnO2:CuO, films have been studied by Field Emission Scanning Electron Microscopy (FESEM), Atomic Force Microscope (AEM) and X-Ray Diffraction (XRD). The effect of CuO doping on the electrical properties of SnO2 films was investigated using Hall effect measurments. The optical properties of the prepared films have been characterized by Ultraviolet-visible spectrophotometer. High distribution densily and good growth SnO2 and SnO2: CuO nanoparticles on the substrate with an average particles size ranged from 30 to 110 nm. The crystalling and grain size were changed according to the CuO doping ratio. There is a redshift within the UV-Vis spectra was observed with an increasing CuO ratio of (3, 5 and 7%)

Fabrication and antibacterial properties of TFC membrane modified with cellulose/copper oxide nanoparticles for removal of cadmium from water

ABSTRACT For achieving a desirable thin film composite (TFC) membrane, accurate selection of raw materials, appropriate process, and manufacturing method for a homogenous dispersion are obligatory. In this study, the manufacturing and characterization of the nanofiltration membranes modified with cellulose/copper oxide nanoparticles for removing cadmium from water were studied. Thin films of nanocomposite membranes were prepared with surface polymerization. The manufactured membranes with different concentrations of copper oxide (0.1, 0.5, and 1 weight percent) and nanocellulose (0.01, 0.05, and 0.1 weight percent) were prepared. At the end of the process and passing for 60 minutes, the pure membrane’s water flux was 238 L/m2.hr. The minimum content of the passing water flux for membrane with 1% CuO and nanocellulose 0.1% (weight percent) was 148 L/m2 hr. The cadmium removal efficiency increases by increasing pH from 2 to 6 for nanocomposite membranes. By increasing pH from 6 to 8, removing cadmium decreases. The cadmium removal of 94% was obtained for the membrane modified with 0.1% CuO and 0.1% nanocellulose. According to the antibacterial test results, an important inhibitory ring is formed around the membrane with a concentration of 1% CuO, which shows this membrane has significant antibacterial properties against Escherichia coli.

Tribological Behavior of Ionic Liquid with Nanoparticles.

This research aims to formulate a new lubricant containing oxide nanoparticles for enhancing anti-wear ability and reducing friction. Different concentrations of copper oxide (CuO) and zinc oxide (ZnO) nanoparticles were separately added to an ionic liquid, methyltrioctylammonium bis(trifluoromethylsulfonyl)imide [N1888] [NTf2], to formulate the tested lubricants. The tribological properties of the lubricants were tested by performing ball-on-disc wear tests on a tribotester (MTM, PCS Instruments). The results show that both the CuO and ZnO nanoparticles can increase the friction reduction ability of the ionic liquid when used as a neat lubricant. The anti-wear characteristic of the ionic liquid is increased by adding ZnO nanoparticles but decreased by adding CuO nanoparticles. The best tribological performance observed for the concentration of 0.2 wt% ZnO, with the wear scar diameter is reduced by 32% compared to the pure ionic liquid. The results of SEM/EDX analysis on the worm morphologies show different lubrication mechanisms of the nanoparticles in the [N1888] [NTf2], which are tribo-sintering for CuO nanoparticles, and third body with pure rolling effect for ZnO nanoparticles.

Nonlinear optical birefringence in Li2SO4-MgO-P2O5 amorphous system -influence of Cu ions

Li2SO4-MgO-P2O5 glasses doped with varied contents of CuO (from 0- 1.0 mol%) were prepared. The optical birefringence induced by a High Q-2 femtosecond pulsed laser is explored as a function of copper oxide concentration in these glasses. The magnitude of the light-induced birefringence exhibited a gradual decrease with the increase of copper oxide content. The observed behavior is discussed in terms of polymerization of the glass network, the degree of which rises with concentration of Cu+ ions occupying Td sites in the glass matrix. However, the samples containing low content of CuO are dominated by Cu2+ ions that act as modifiers and induce structural imperfections by breaking of P-O-S bonds. Accordingly, the samples mixed with lower content of CuO are more favorable for inducing higher magnitudes of the optical birefringence. This conclusion is corroborated by results of electrical conductivity, positron annihilation and ultrasonic measurements.

Preparation and Characterization of In2O3-CuO Nanocomposite Thin Films as NH3 Gas Sensor

An NH3 gas sensor was prepared from nanocomposite films of indium oxide-copper oxide mixtures with ratios of 0 , 10 , and 20 Vol % of copper oxide. The films were deposited on a glass substrate using chemical spray pyrolysis method (CSP) at 400oC. The structural properties were studied by using X-ray diffraction (XRD) and atomic force microscopy ( AFM). The structural results showed that the prepared thin films are polycrystalline, with nano grain size. By mixing copper oxide with indium oxide, the grain size of the prepared thin films was decreased and the surface roughness was increased. The UV-Visible spectrometer analysis showed that the prepared thin films have high transmittance. This transmittance was decreased by mixing copper oxide with indium oxide. The direct optical energy gap ranged 3.5 - 3 eV, which was decreased with increasing copper oxide concentration. The sensitivity of the prepared gas sensor was measured towards NH3 gas at a concentration of 71ppm with operating temperatures of 100, 150, 200, 250 and 30) oC, according to the change of sensor resistance. This sensitivity of the mixture oxides showed a value of about nine times greater than that of individual indium oxide thin films. The results of the optimum gas sensor properties demonstrated a sensitivity value of 75.06%, response time of 10s, and recovery time of 11 s, at a mixing ratio of 20% of copper oxide and an operating temperature of 200oC.