Cadmium oxides

Electrochemical water splitting is one of the promising way to enhance energy with less outflow. In this regard different electrocatalysts have been reported for Oxygen evolution reaction (OER) to get alternative of noble metal based electrocatalysts. In this work, we have introduced Cadmium-oxide/Cobalt-oxide (CdO/Co3O4) nanocomposite by co-precipitation chemical strategy with impressive OER performance in alkaline medium. Almost 310 mV overpotential value is required to achieve 10 mA/cm2 current density with Tafel slope value of 62 mV/Dec. The as synthesized nanocomposite has stability of 6h as its longer electrochemical performance

Rapid breakdown anodization (RBA) process was used to fabricate TiO2 sensor to measure pressure and humidity and sense gases at room temperature. This chemical process transformed Ti to its oxide (TiO2) as a powder with amorphous phase as X ray diffraction (XRD) technique confirmed.  This oxide consisted from semi spherical nanoparticles and titania nanotubes (TNTs) as Scanning electron microscope (SEM) technique showed.  TiO2 powder was deposited on Ti substrates by using electrophoretic deposition (EPD) method.   Average pressure sensitivity was 0.34 MΩ/bar and hysteresis area was 1.4 MΩ .bar. Resistance of TiO2 decreased exponentially with the increasing of relative humidity (RH%). The sensitivity% of TiO2 for RH% was greater than 70% in the range of (50-95). TiO2 was tested as a sensor for Ammonia, Ethanol and Methanol. Its sensitivity and selectivity towards Ammonia were the greatest but the shortest response and recovery times were recorded toward Methanol.

Alkaline nickel-cadmium batteries are among the most used industrial high-power sources. Despite stricter environmental requirements, nickel-cadmium batteries still remain as the main choice for highly reliable power sources for heavy-loaded equipment. Therefore, recovery of cadmium (Cd) from spent batteries is a challenge for the modern recycling industry, particularly as it displays high bio-toxicity. The present study describes a new green approach for Cd recovery from cadmium oxide (CdO). The paper discusses using a ternary chloride composition consisting of calcium, potassium and sodium chloride, thereby avoiding the release of Cd vapour from the reaction volume during the reduction reaction from CdO. For the protective slag layer during the reduction process (which occurs at 650 °C), a 0.515:0.0796:0.405 molar ratio of CaCl2:KCl:NaCl was chosen, with the aim of achieving a melting point at 483 °C. To describe phase and elemental composition of obtained products X-ray diffracti...

The magnetism of nanoparticles and thin films of wide-bandgap oxides that include no magnetic cations is an unsolved puzzle 1. Progress has been hampered by both the irreproducibility of much of the experimental data, and the lack of any generally accepted theoretical explanation. The characteristic signature is a virtually anhysteretic, temperature-independent magnetization curve that saturates in an applied field that is several orders of magnitude greater than the magnetization. It would seem as if a tiny volume fraction, 0.1%, of the samples is magnetic and that the energy scale is unusually high for spin magnetism. Here we investigate the e ect of dispersing 4 nm CeO 2 nanoparticles with powders of γAl 2 O 3 , sugar or latex microspheres. The saturation magnetization, M s ≈ 60 A m −1 for compact samples, is maximized by 1 wt% lanthanum doping. Dispersing the CeO 2 nanopowder reduces its magnetic moment by up to an order of magnitude, and there is a characteristic length scale of order 100 nm for the magnetism to appear in CeO 2 nanoparticle clusters. The phenomenon is explained in terms of a giant orbital paramagnetism that appears in coherent mesoscopic domains due to resonant interaction with zero-point fluctuations of the vacuum electromagnetic field. The theory explains the observed temperature-independent magnetization curve and its doping and dispersion dependence, based on a length scale of 300 nm that corresponds to the wavelength of a maximum in the ultraviolet absorption spectrum of the magnetic CeO 2 nanoparticles. The coherent domains occupy roughly 10% of the sample volume. There is a class of thin films and nanoparticles of oxides that exhibit ferromagnetic-like magnetization curves, although the materials lack the concentration of ions with unpaired d or f electron spins required to generate the exchange interactions needed for high-temperature ferromagnetism 1. This is forcing a re-evaluation of the meaning of magnetic saturation in systems that exhibit very little hysteresis. Research in this area has been plagued by a shortage of reproducible experimental data, so there is need for an easily synthesized 'fruitfly' system that reliably exhibits stable anomalous magnetism for which no extraneous explanation is possible. The much-studied dilute Co-doped ZnO thin films 2 were problematic because metallic cobalt nanoparticles, difficult to detect in ZnO films 1-4 , are ferromagnetic with a high Curie temperature. The reports of magnetism in these oxide systems have shown that a 3d dopant is unnecessary, and even when 3d ions are present they do not necessarily order magnetically 5-8. The magnetism is somehow related to defects; candidates include cation 9 or oxygen 10 vacancies (F-centres). Sundaresan et al. 11 have suggested that weak room-temperature magnetism could actually be a general feature of oxide nanoparticles. A significant observation was that the magnetism appearing in undoped 10 nm ZnO nanoparticles

Alkaline nickel-cadmium batteries are among the most used industrial high-power sources. Despite stricter environmental requirements, nickel-cadmium batteries still remain as the main choice for highly reliable power sources for heavy-loaded equipment. Therefore, recovery of cadmium (Cd) from spent batteries is a challenge for the modern recycling industry, particularly as it displays high bio-toxicity. The present study describes a new green approach for Cd recovery from cadmium oxide (CdO). The paper discusses using a ternary chloride composition consisting of calcium, potassium and sodium chloride, thereby avoiding the release of Cd vapour from the reaction volume during the reduction reaction from CdO. For the protective slag layer during the reduction process (which occurs at 650 • C), a 0.515:0.0796:0.405 molar ratio of CaCl 2 :KCl:NaCl was chosen, with the aim of achieving a melting point at 483 • C. To describe phase and elemental composition of obtained products X-ray diffraction analysis and energy dispersive X-ray spectroscopy, respectively, were applied. Electron and optical microscopy were used for morphological observations. The presence of the metallic Cd was noted. During the reduction reaction, it was noted that slag separated into two parts: a protective upper layer and bottom layer. It was also noted that metallic Cd accumulated with increasing reaction time in the bottom part of the slag.

Copper oxide (CuO) nanoflowers were synthesized by a reproducible and inexpensive wet chemical method. The synthesized CuO nanoflowers were characterized by x-ray diffraction, Raman spectroscopy, x-ray photoelectron spectroscopy, field emission scanning electron microscopy and energy-dispersive spectroscopy. For an optimized operating temperature of 240°C, the sensor characteristics of the gas sensing device were measured using acetone as a volatile gas. The synthesized CuO nanoflower-based gas sensor responded very strongly for acetone gas concentrations in the range of 250-2250 ppm, and the recorded response for concentrations of 250 ppm and 2250 ppm was 2.7 and 7.2, respectively. The stability of the synthesized sensor was checked by repeating the measurements over a period of 1 month, and a very small change of 3.3% in the response of the sensor was observed.

The study here deals with the plant synthesis of cadmium oxide nanoparticles using flowers extract ofAchillea wilhelmsiias the reducing agent. The photosynthesis is carried out at room temperature in the laboratory ambience. The aqueous cadmium ions when exposed to flower extract were reduced and resulted in their nanoparticles. The synthesized nanoparticles were characterized using techniques such as scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and UV-visible absorption spectroscopy. Stable cadmium oxide nanoparticles were formed by treating aqueous solution of cadmium chloride (CdCl2) with the plant flower extracts as reducing agent.

Electrochemical water splitting is one of the promising way to enhance energy with less outflow. In this regard different electrocatalysts have been reported for Oxygen evolution reaction (OER) to get alternative of noble metal based electrocatalysts. In this work, we have introduced Cadmium-oxide/Cobalt-oxide (CdO/Co3O4) nanocomposite by co-precipitation chemical strategy with impressive OER performance in alkaline medium. Almost 310 mV overpotential value is required to achieve 10 mA/cm2 current density with Tafel slope value of 62 mV/Dec. The as synthesized nanocomposite has stability of 6h as its longer electrochemical performance

Nanopowders of ZnO codoped with Al and Cd ions (ZnO:Al:Cd) were synthesised by thermal co-decomposition of a mixture of Zn and metals complexes. X-ray diffraction analysis using the Rietveld method confirmed the formation of single nanocrystalline structure, thus, both Al and Cd ions are incorporated into ZnO host lattice forming solid solutions (SSs). Optical properties measured by diffuse reflectance spectroscopy (DRS) revealed a redshift associated with the creation of point defects and that the energy band gap is slightly affected by doping; i.e. 3.23-3.12 eV. Annealing of the as-synthesised SSs in H 2atmosphere (hydrogenation) was conducted in order to clarify the reinforcement and/or the creation of ferromagnetic order. Magnetic measurements showed that ZnO doped with 1.2at% Al and 0.6at%Cd became ferromagnetic with a coercivity ~ 100 Oe, remanence ~ 1.4 memu/g and saturation magnetization of ~ 6.5 memu/g. Moreover, hydrogenation of undoped diamagnetic (DM) ZnO transformed into ferromagnetic. To elucidate the changes on the optical properties due to presence of dopants (Al, Cd) and the vacancies, we have employed first principle calculations based on density functional theory to calculate the optical properties and the change operated in the band gap due to structural changes. The observed RT-FM was associated to the doping and vacancies created by the hydrogenation.

We investigated the effects of both intrinsic defects and hydrogen atom impurities on the magnetic properties of MgO samples. MgO in its pure defect-free state is known to be a nonmagnetic semiconductor. We employed density-functional theory and the Heyd–Scuseria–Ernzerhof (HSE) density functional. The calculated formation energy and total magnetic moment indicated that uncharged $${\mathrm{V}}_{\mathrm{Mg}}^{0}$$ V Mg 0 and singly charged $${\mathrm{V}}_{\mathrm{Mg}}^{-1}$$ V Mg - 1 magnesium vacancies are more stable than oxygen vacancies (VO) under O-rich growth conditions and introduce a magnetic moment to MgO. The calculated density of states (DOS) results demonstrated that magnetic moments of VMg result from spin polarization of an unpaired electron of the partially occupied valence band, which is dominated by O 2p orbitals. Based on our calculations, VMg is the origin of magnetism and ferromagnetism in MgO. In contrast, the magnetic moment of the magnetic VMg-MgO crystal is s...

Electrochemical water splitting is one of the promising ways to enhance energy with less outflow. In this regard different electrocatalysts have been reported for Oxygen evolution reaction (OER) to get alternative of noble metal based electrocatalysts. In this work, we have introduced Cadmium-oxide/Cobalt-oxide (CdO/Co3O4) nanocomposite by co-precipitation chemical strategy with impressive OER performance in alkaline medium. Almost 310 mV overpotential value is required to achieve 10 mA/cm2 current density with Tafel slope value of 62 mV/Dec. The as synthesized nanocomposite has stability of 6h as its longer electrochemical performance.

We have synthesized pure, mixed and multicomponent structures by coupling different cost-effective techniques. Prepared TiO2-based hierarchically assembled nanostructures have been thoroughly characterized by scanning electron microscope, X-ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy. The sensing properties of materials have been studied towards explosive and toxic gaseous compounds. Investigations have shown the material crystalline structure, the variation of mixture concentration in the material and the modification of carbon-based layers have crucial effect on the response and the selectivity of materials. The obtained results demonstrate that the prepared multicomponent structures can be applied in the area of chemical sensors for the environmental monitoring and medical diagnoses.

Magnetic properties of reduced T'-Pr 2-x Ce x CuO 4 (T'-PCCO) nanoparticles with x = 0, 0.10, and 0.15 have been investigated. The T'-PCCO samples were synthesized by the chemically dissolved method with HNO 3 as dissolving agents and by the succeeding calcination at 1000°C for 15 h in air. The reduced T'-PCCO samples were obtained by the reduction annealing at 700°C for 10 h in Argon atmosphere and at 700°C for 12 h in vacuum. Rietveld analyses of the X-ray diffraction (XRD) patterns for all the samples have revealed dependences of the c-axis length and the crystal size on the Ce doping and the reduction annealing. XRD analyses and transmission electron microscopy (TEM) images have confirmed T'-PCCO nanoparticles with the size of around 40-100 nm. Magnetic properties of all the T'-PCCO nanoparticles were studied by a superconducting quantum interference device (SQUID) showing a dominant paramagnetic feature with very weak ferromagnetism in the as-synthesized samples at room temperature. It has changed to a pure paramagnetic feature after the reduction annealing in argon atmosphere and an enhanced ferromagnetism through vacuum annealing. This is probably due to the change in the number of oxygen vacancies through the defect recovery and the removal of excess oxygen after both reduction annealing processes, respectively.

We report on the surface interaction between NH 3 and WO 3 nanoparticles having different exposed surfaces or different porous structure, to identify the relative importance of exposed crystal surfaces, porous architecture, and specific surface area in the oxide sensing properties. WO 3 nanocrystals with tailored morphology and definite prominent surfaces were synthesized by hydrothermal reactions. In parallel, inverted opal macroporous WO 3 films have been prepared by a one-step sol-gel procedure, and WO 3 hierarchical layers have been obtained by an innovative one-step dual-templating strategy which leads to macropores and mesopores simultaneously. The performances of WO 3 samples in NH 3 sensing, indicate that high-energy surfaces result in a significant improvement of the electrical response. Enhanced porous structure and high surface area are not enough to produce high electrical response, while their synergistic combination with tailored crystal faceting appears effective. XPS survey performed on shape controlled WO 3 nanocrystals demonstrated that, upon interaction with NH 3 , oxidized nitrogen atoms represent the prevalent species on the surface of rectangular (WO 3-RE) nanocrystals with highly exposed high-energy {020} and {002} facets. Conversely, in the case of rectangular platelets (WO 3-SS) and square platelets (WO 3-RS) with very low surface area of high-energy surfaces, N-H surface groups are predominant. These results suggest that {020} and {002} crystal surfaces provide privileged reactive sites for ammonia oxidation and therefore they play a key role in driving the sensing properties of the WO 3 layers.

Introduction: Pseudomonas aeruginosa is a key opportunistic pathogen causing severe acute and chronic nosocomial infections in immunocompromised or catheterized patients. It is prevalent in burn wound infections and is generally multi-drug resistant.This study evaluated antimicrobial activity of ZnO nanoparticles, catechin and EDTA on the most common pathogen bacteria, Pseudomonas aeroginusa, by standard microdilution test depending on NCCLS. Material and Methods: Zinc acetate dehydrate and ethilen glycol (EG) were dissolved in 50 ml distilled water with a ratio of 10/1 (Zn/EG). The solution was heated at 80 0 C until a little gel of zinc acetate was obtained. Then, the gel was dried in the oven for 12h. The dried gel was calcinated at 300 0 C for 24h. The size and type of these nanoparticles were characterized by scanning electron microscopy (SEM) and X-Ray: Diffraction (XRD). Pseudomonas aeroginusa strain (ATCC 27853) were cultured on nutrient agar medium (NA) for 24h at 37 0 C. The microbial suspension (1×10 6 cells/ml) was prepared. Minimum Inhibitory Concentration (MIC) test for ZnO, EDTA and Catechin were evaluated by microdilution test. Results: Evaluation of morphology and measurement of the size of the ZnO showed that nanoparticles were spherical with a diameter of 30-90 nm. MIC of ZnO, EDTA and Catechin on pseudomonas aeroginusa was 0.0003, 24.92 and 7.24 µg/ml, respectively. Conclusion: In this study, ZnO nanoparticles were synthesized using the chemical method. It was revealed that it has an optimal antimicrobial activity in low concentration as compared with Catechin and EDTA. It is recommended that catechin and ZnO nanoparticles are good candidates for eliminating some contaminations including Pseudomonas aeroginusa in medical industrial.

Structural aspects, such as grain size, pore size, and crack-free film morphology, of porous silicon (PS), etc., play a vital role in the sensing of volatile organic compounds (VOCs). This chapter discusses a novel method for sensing of VOCs using porous silicon coated with a layer of ZnO (PS-ZnO). It was noted that the sensing ability of the PS sensor has increased due to the transconductance mechanism, as a result of the coating of ZnO over PS. Initially, porous silicon is formed by electrochemical wet etching of silicon and by electrophoretic deposition (EPD), ZnO is coated over porous silicon. An increase in the selectivity is due to the increase in surface-to-volume ratio and uniformity in the pore structures. The thickness of ZnO layer can be tuned up to 25 nm by applying a DC voltage between the copper electrode and the conductive silicon substrate immersed in a suspension of ZnO quantum dots. The influence of quantum dot concentration on the final layer thickness was studied by X-ray diffraction (XRD). The change in resistance for ethanol was found to be 12.8-16 MΩ and 8-16 MΩ for methanol.

Background: Inorganic antibacterial factors have bacterial resistance and high thermal stability. Inorganic
nanomaterials which have new structures with biological, chemical and physical properties have been made
since their applications due to their nano size. In this study, the antibacterial effect of cadmium oxide
nanoparticles on Staphylococcus aureus and Pseudomonas aeruginosa bacteria was investigated.
Materials and Methods: The different concentrations (10 μg/ml, 15 μg/ml and 20 μg/ml) of cadmium oxide
nanoparticles were prepared and their effects were studied against considered bacteria in both solid and
liquid media.
Results: The results showed that there is a direct relationship between inhibitory effect and amount of
consumer dose of nanoparticles. Furthermore, it was observed that antibacterial properties of cadmium oxide
nanoparticles on activity and growth of Staphylococcus aureus was more effective than Pseudomonas aeruginosa.
Conclusion: This study showed that antibacterial effects of cadmium oxide nanoparticles on positive gram bacteria
are stronger than negative gram bacteria and antibacterial effects of cdo nanoparticles against both bacteria,
but Staphylococcus aureus bacteria were more sensitive to nanoparticles as compared to Pseudomonas aeruginosa.

For many centuries, the metals are used as the antibacterial factors. Whereas, the nanoparticles are mostly heavy metal oxides, they have a high tendency to interact with biological molecules and develop the deactivation or elimination of the virus or bacteria. In the present study, the antibacterial effect of Cadmium Oxide nanoparticles on Pseudomonas Aeruginosa bacteria was analyzed which are considered some sort of resistant bacteria against antibiotics now. The aim of his study was to investigate the antibacterial properties of onekind of nno-specimen (cdo) against Pseudomonas Aeruginosa. Our study was research perusal. In the first study, the optical density of Pseudomonas Aeruginosa culture was observed in the presence of 5, 10, 15µg/ml. in the scond study, 600nm of Pseudomonas Aeruginosa was separately exposed to nanoparticles at 37° c in water. In third study, we studied thew growth of Pseudomonas Aeruginosa in solid medium with and without nanoparticles. The results represented that there is a direct relation between the nanoparticles applied dosage and the restrain effect-augmentation of applied dosage results in restrain effect increase. In the study of environmental factors (pH and temperature), the results are in line with the inherent physiology of the bacteria, however, there was a significant decline in the number of analyzed bacteria cells due to the Double Effect of nanoparticle-pH variations as well as nanoparticle-temperature variations. In the present study, enhancement in

The work reported here deals with synthesis and characterization of cadmium oxide nanoparticles. The main goal of this synthesis to study antibacterial effects of cadmium oxide nanoparticles. This study includes characterization using microscopic and spectroscopic studies.

Highly sensitive and selective detection of volatile organic compounds (VOCs) with fast response time is imperative based on safety requirements, yet often remains a challenge. Herein, we propose an effective solution, preparing a novel gas sensor comprised of amorphous nanoflake arrays (a-NFAs) with specific surface groups. The sensor was produced via an extremely simple process in which a-NFAs of CdO were deposited directly onto an interdigital electrode immersed in a chemical bath under ambient conditions. Upon exposure to a widely used VOC, diethyl ether (DEE), the sensor exhibits excellent performance, more specifically, the quickest response, lowest detection limit and highest selectivity ever reported for DEE as a target gas. The superior gas-sensing properties of the prepared a-NFAs are found to arise from their open trumpet-shaped morphology, defect-rich amorphous nature, and surface C]O groups.

We obtain a single cadmium oxide phase from powder synthesized by a thermal decomposition method of cadmium acetate dehydrate. The yielded powder is annealed in air, vacuum, and H 2 gas in order to create point defects. Magnetization-field curves reveal the appearance of diamagnetic behavior with a ferromagnetic component for all the powders. Powder annealing under vacuum and H 2 atmosphere leads to a saturation magnetization 1.15 memu g À1 and 1.2 memu g À1 respectively with an increase by 45% and 16% compared to the one annealed in air. We show that annealing in vacuum produces mainly oxygen vacancies while annealing in H 2 gas creates mainly Cd vacancy leading to room temperature ferromagnetic (RTFM) component together with known diamagnetic properties. Ab initio calculations performed on the CdO nanoparticles show that the magnetism is governed by polarized hybrid states of the Cd d and O p orbitals together with the vacancy.

This contribution reports on the synthesis and the main physical properties of CdO nanoparticles synthesized
for the first time by a completely green process using Agathosma betulina plant extract as an
effective bio-oxidizing/bio-reducing agent. The surface/interface and volume room temperature properties
by HRSEM, EDS, XRF, XRD, ATR-FTIR, Raman, XPS and Photoluminescence are reported.