CdO Concentration Research Articles

Radiation shielding potential of cellulose acetate-CdO-ZnO polymer composites in comparison with concrete and gypsum

Radiation shielding using polymer composites is becoming more attractive because of their ease of production, lightness, ruggedness and availability. In this work, linear attenuation coefficient (LAC) and tenth value layer (TVL) of Cellulose Acetate - CdO - ZnO Polymer Composites of different concentrations of CdO and ZnO denoted as PB1, PB2 and PB3 were investigated against concrete and gypsum. Cellulose Acetate-CdO-ZnO Polymer Composites were prepared using the open mold cast technique and have been investigated for x-rays shielding ability. Cellulose acetate is a biodegradable good matrix, while CdO and ZnO are good fillers for absorbing x-rays in the diagnostic energy range. Scanning Electron Microscopy (SEM) technique was used to observe the uniform dispersal of fillers within the matrix. X-rays attenuation coefficients were calculated by XCOM computer code for all the samples using the average energies commonly used in diagnostic radiology practice - 20 keV, 30 keV, 40 keV and 60 keV. The SEM confirmed the dispersal of the fillers (CdO and ZnO) within the matrix. The result of this investigation showed that all the polymer composites (PB1, PB2 and PB3) have higher LACs and lower TVLs over gypsum and concrete at 20 keV, 30 keV, 40 keV and 60 keV. Tenth Value Layers (TVLs) of all the polymer composites is less than 1 cm at 20 keV, 30 keV and 40 keV.

Neutron Shielding Properties of Cellulose Acetate CdO-ZnO Polymer Composites

In this work, the neutron shielding ability of Cellulose Acetate-CdO-ZnO Polymer Composites of different concentrations of CdO and ZnO were investigated. Cellulose acetate is a biodegradable good matrix and the used metal oxides are good for absorbing radiation. The neutron attenuation coefficient was calculated by Phy-X computer code for all the samples.

Unveiling the synergistic effect of Cd doping on structural, optical, mechanical, and γ-ray shielding characteristics of zinc lead silicate glass

Using the traditional melt quenching process, the glass series of xCdO-(5-x) ZnO-35Pb3O4-60SiO2, where x = 1–5 mol%, were created. The X-ray diffraction method was utilized to investigate the non-crystallinity of the glasses that were created. The densities of the fabricated glasses increased from 5.91 to 6.655 g/cm³. Electronegativity (ΔX), bond density (nb), and field strength (F) were calculated. ΔX decreased while nb and F increased with the supply of Cd ions. The optical characteristics Eg, n, αo, εr, χ(3), n2, M, T and more have been investigated. We found that a change in cadmium concentration in the fabricated system influenced all the optical parameters. The mechanical properties, including elastic moduli, have been investigated alongside ultrasonic velocity measurements. The experimental results demonstrated a strong dependence of calculated parameters on increasing CdO concentration. The observation indicates an increase in the elastic moduli with the increasing CdO concentration. Radiation shielding factors were estimated using EpiXS program. μL, HVL, MFP, Zeff, Neff, EBF and EABF for gamma energy between 15 and 15,000 KeV have been investigated. The results indicate that these parameters are affected by the introduction of CdO content into the glass network. The sample ZPSCd5 exhibits the highest radiation shielding parameters among the studied glass samples.

Cadmium-modified iron lead borate glasses for radiation protection

Using cadmium-modified iron lead borate glasses with formula 30 B2O3 – 40 PbO – 10 Na2O – (20 -x) Fe2O3 – x CdO where x ranges from 0 to 20 mol%, this work aims to investigate the structural, physical, elastic, and radiation-shielding properties of practical economic radiation shields. The X-ray diffraction patterns confirm the amorphous nature of the samples. The results of Fourier-transform infrared spectroscopy (FTIR) demonstrate the formation of robust B–O–Cd linkages and diborocadmium ([B2CdO8]2−) structures, as well as the conversion from [BO3] to [BO4] structural units with increased CdO and the presence of PbO and Na2O as modifiers. The CdO function also plays a dual role as a former and as a modifier. The FTIR analysis showed that the material's elasticity and the CdO oxide concentration were directly correlated, suggesting that the glass system becomes stiffer as the CdO concentration increases. The study explores the effectiveness of radiation shielding and demonstrates that CdO-rich samples have higher effective atomic numbers and attenuation qualities.

AP-1000 fuel assembly performance with cadmium oxide as a new burnable poison

ABSTRACT One of the main nuclear reactor design problems is finding an efficient method for reactivity control. Boron-free small modular reactors and long-life pressurized water reactors need proper neutron absorbers to suppress large initial reactivity and gentle reactivity variation during reactor operation. In this paper, AP-1000 fuel assembly is used to investigate the effect of using cadmium and enriched Cd113 as burnable poisons. The reactivity behavior of the AP-1000 fuel assembly is of interest. The DRAGON code calculates the neutronic performance of the natural and enriched UO2-CdO. The investigation is performed from the standpoint of initial reactivity, reactivity swing, pin power peaking factor, and cycle length. As a further check, the impact of the CdO on the MTC results is also explored. Moreover, the results are compared with those of gadolinia-bearing rods. Fully enriched cadmium oxide (enriched in Cd113) provides 10.5% more initial reactivity suppression than that of gadolinia fully enriched by Gd157 while reaching almost the same cycle length. Also, using cadmium enriched in Cd113 leads to reducing parasitic absorption. The reactivity swing of the case fully enrichment of Cd113 is 21% lower than the case with natural cadmium rods. It is also found that the residual binding of the CdO with 100%Cd113 enrichment and Gd2O3 with 100%Gd157 enrichment are 0.002928 and minus 0.0026 respectively. Moreover, it is seen that, the normalized pin power for 2 w/o concentration of CdO fully enriched Cd113 has been increased by 3.3% relative to the case with Nat. Cd.

Influence NiO on the structure, elastic properties and buildup factor of BaO-CdO-borosilicate glasses

In this work, the structure, elasticity parameters, and buildup factor of borosilicate glasses doped with BaO, CdO and NiO have been studied. Infrared (IR) spectroscopy was utilized to study the internal structure of the present system. IR spectra are broad, especially since the superposition between the borate and silicate occurs in the same spectral region. A deconvolution process was carried out to extract these spectra into their individual bands. The values of tetrahedrally-coordinated boron atoms ratio () barely increased from 37.9% for 1 mol% of NiO to 39.5% for 4 mol% of NiO. This increase indicates the transformation of three coordinated boron atoms () to four coordinated boron atoms () units with further NiO additions. The values were used along with the dissociation energies density and packing density parameters to calculate the elastic moduli; Young, shear, bulk, and Poisson ratio. The obtained values of Young’s modulus increase with further NiO additions. This increased behavior of Young’s modulus demonstrates the augmented ability of the current glasses to withstand variations in their length under lengthwise tensile tension or compression with further NiO additions. The rest of the elasticity moduli showed increased behaviors as well. These increased behaviors support the results obtained from structural properties analyses. An increment of BO4 units with decreasing the nonbridging oxygens ions (NBO) in the internal structure of present glasses produces an increase in the elastic parameters of these glasses. At photons energy of 0.2 MeV, the energy exposure buildup factor (EBF) values are low for glasses with a high concentration of CdO (low concentration of NiO), but the value of EBF is larger for glasses with a low concentration of CdO (high concentration of NiO).

Optical and Electrical Transport Properties of the ZnO:CdO Composite Film

In this work, zinc oxide films and composite ZnO:CdO films with cadmium oxide concentrations of 3 , 5 , 7 , 10 , and 12 were obtained by spin-coating on FTO. The films were annealed in the atmosphere under the same temperature conditions of 450°C. The morphology of ZnO:CdO composite films was studied by the SEM method and an electron-dispersion analysis of the concentration of the studied substance was carried out. The influence of the surface morphology of the composite film with an increase in the CdO concentration from 3 to 12 on the optical and electrotransport properties of the ZnO:CdO composite film was studied. The optical absorption spectra of composite films of zinc oxide and cadmium were measured. ATauc plot is presented to determine the band gap of a ZnO:CdO composite film. It has been established that an increase in the CdO concentration on the ZnO surface leads to a decrease in the optical band gap. The observed decrease in the optical band gap of the film with increasing CdO is due to the small band gap of CdO. The method of impedance spectroscopy was used to study the main electrophysical characteristics, in particular, the dynamics of charge carrier transfer in nanocomposite films based on ZnO:CdO. It has been established that the CdO layer on the ZnO surface contributes to a decrease in the resistance value of the composite film Rw, an increase in the charge recombination resistance parameter Rrec at the interface, and an increase in the efficiency of electron injection.

Assessment of mechanical and radiation shielding capacity for a ternary CdO–BaO–B2O3 glass system: A comprehensive experimental, Monte Carlo simulation, and theoretical studies

A Glass system consisting of ternary BaO, B2O3, and CdO compounds was fabricated using the melt-quenching method. The fabricated glasses density was measured using the Archimedes method and reduced in the range between 3.148 and 2.955 g/cm3, raising the CdO concentration in the glass network. The elastic moduli and some mechanical properties were calculated for the fabricated glasses based on the Makishima-Mackenzie model. The obtained results showed a diminished in Young, bulk, shear, longitudinal moduli, and the microhardness of the fabricated glass with the replacement of the BaO by CdO compounds. Moreover, the linear attenuation coefficient of the fabricated samples was measured via NaI detector at energies 0.662, 1.173, and 1.332 MeV emitted by the radioactive sources Cs-137and Co-60. The experimental data was confirmed using the XCOM program and Monte Carlo simulation. The highest linear attenuation coefficient is obtained for the fabricated glass without CdO content. It is decreased from 74.49 to 0.086 cm−1 between 0.015 and 15 MeV. Furthermore, the effect of partial replacement of BaO by CdO compounds on the effective removal cross-section for the fast neutrons was evaluated theoretically. Based on this factor, the fabricated glasses' relaxation length and half-value layer were also calculated.

Estimation of radiation protection ability of borate glass system doped with CdO, PbO, and TeO2

This report presents the gamma-rays and neutron interacting parameters of the newly developed xCdO – 20PbO–10TeO2 – (69-x) B2O3–1CuO glass system with the view to applying them for nuclear protection uses. The glasses were coded as CdPTBCu1 – 4 representing molar concentration of CdO form 0–15%. The mass attenuation coefficient (MAC) of the glasses at gamma radiation energies 662–2506 keV were estimated using FLUKA. Monte Carlo simulation and NIST library. The simulation results compared well with that of NIST library within 2% margin. The MAC declines with energy but generally increases as CdO concentration increases in the glasses. At 0.284 MeV, the MAC values of CdPTBCu1, CdPTBCu2, CdPTBCu3, and CdPTBCu4 were equal to 2.459×10−1, 2.458×10−1, 2.457×10−1, and 2.447×10−1 cm2/g, respectively. While at 2.51 MeV, the values were 4.023×10−2, 4.023×10−2, 3.982×10−2, and 3.994×10−2 cm2/g, respectively. Other photon shielding factors like the effective atomic layer, transmission factor, self-absorption correction factor, and mean free path show that the increase in CdO content improves the photon shielding abilities of CdPTBCu specimens. Furthermore, the fast neutron removal cross section (ΣR) and their total thermal neutron cross section (σT) of the glasses were estimated. ΣR increased from 0.10211 to 0.10775 cm−1 while σT grew from 111.21 to 442.73 b. The increase in CdO content had a positive impact on the photon, fast, and thermal neutron shielding ability of the CdPTBCu glasses. Comparatively, the photon and neutron shielding ability of the present glass system is superior to some conventional and recently studied glass shields. The CdPTBCu glasses are thus potentially useful as photon and neutron absorbers for nuclear radiation protection applications.

Selectively enhanced gas-sensing performance to n-butanol based on uniform CdO-decorated porous ZnO nanobelts

Due to its porous structure and synergetic sensing effect, the as-prepared CdO-decorated porous ZnO nanobelts exhibit a greatly enhanced sensing selectivity to n-butanol with a low detection limit of less than 5 ppb and excellent stability/repeatability. • CdO-decorated porous ZnO nanobelts were prepared through a cation-exchange reaction and subsequent calcination in air. • As-prepared porous nanobelts exhibited an enhanced selectivity to n-butanol with excellent stability/repeatability. • The excellent sensing performance is mainly ascribed to porous structure and synergetic sensing effect of CdO and ZnO. ZnO porous nanobelts decorated with different concentrations of CdO were precisely prepared via a two-step approach consisting of a cation-exchange reaction and subsequent calcination in air. After partially exchanged with Cd 2+ , the morphology of the ZnSe∙0.5N 2 H 4 precursor nanobelts was well preserved due to the spatial confinement effect. When thermally oxidized in air, the partially exchanged precursor nanobelts were changed into ZnO porous nanobelts decorated with CdO. Notably, CdO was uniformly distributed on the porous ZnO nanobelts. In contrast to bare porous ZnO nanobelts, the as-prepared CdO-decorated porous ZnO nanobelts exhibited a better sensing performance to volatile organic compounds. Moreover, an enhanced sensing selectivity to n-butanol was obtained. 9 at% CdO-decorated porous ZnO nanobelts displayed the best relative response of approximately 112 to 10 ppm of n-butanol. In addition, a low detection limit of less than 5 ppb was achieved with excellent stability and repeatability, suggesting that the fabricated gas sensors based on CdO-decorated porous ZnO nanobelts can be used for practical applications.

γ-ray effects on PMMA polymeric sheets doped with CdO nano particles

The present work aimed to study the γ-ray irradiation effects on the physical and chemical behavior of poly methyl methacrylate (PMMA) thin polymeric sheets doped with different concentrations of nano CdO (0.3–1.8 wt. %). Co-precipitation technique was used to prepare CdO nanopowder, while casting-solution method was applied to prepare thin sheets of PMMA/CdO. The XRD analysis of CdO, PMMA and their composites confirmed their formation in pure phase. The particle size distribution of the CdO powder was estimated using TEM imaging and found to be 3–20 nm. According to optical microscopy investigation, good homogeneous distribution was obtained for the CdO powder inside the PMMA sheets. Different sets of the prepared samples were irradiated by γ-ray of 60Co source with gradually increasing doses (20–120 kGy). The irradiated samples were analyzed using XRD, FTIR and UV/Vis spectroscopy. Comparative study was done on pristine and irradiated samples at different CdO concentration. The visual appearance of the samples showed chromatic degradation with increasing both CdO concentration and absorbed γ-ray doses. A color map of the irradiated PMMA/CdO samples was presented for monitoring the absorbed dose. The changes in the samples color was attributed to conversion of CdO (reddish brown) to Cd(OH)2 (clear white) as a result of γ-ray irradiation. The unirradiated samples showed slight decrease in their optical band gap with increasing CdO concentration. Furthermore, a linear correlation between the optical band gap and γ-ray dose was deduced for all the irradiated samples. Electrical permittivity and conductivity of pristine and irradiated samples were measured as a function of frequency at room temperature using LCR bridge. A relative increase in the dielectric constant and AC conductivity of the irradiated samples by about 5–25% was observed for the highest CdO concentration. The electrical parameters of the irradiated samples showed significant changes at high γ-ray dose of 120 kGy. The obtained experimental data were discussed in view of γ-ray interaction with the medium using the suitable models and theories of polarization mechanisms. The results are promising for using the prepared samples as γ-ray dosimeters in addition to enhancement of their electrical properties for various applications.

Novel cadmium substituted barium zinc niobate perovskites: Phase formation, structural and impedance studies

Herein we report the structural and impedance properties of the novel Cd-substituted perovskites, Ba(Zn1/3-xCdx)Nb2/3O3 (BZCN), 0 ≤ x ≤ 0.333, prepared by solid-state reaction at 1000 °C for 17 h. The doping mechanism of this complete substitutional solid solution was proposed to be a one-to-one replacement of Zn2+ by Cd2+ as to maintain the overall electroneutrality of the system. BZCN perovskites crystallised in a cubic symmetry, space group Pm3m, Z = 1 and their refined lattice constants, a = b = c were found to be in the range 4.0917(3)-4.1693(13) Å. A moderate unit cell expansion was discernible with increasing CdO concentration, thus portraying a linear correlation between lattice constant and composition that obeyed the Vegard's law. The surface microstructures of these BZCN perovskites were composed of irregular polyhedral grains and their determined crystallite sizes by both Scherrer and Williamson-Hall methods were found to be in the range 21.0–44.8 nm. Both TGA and DTA analyses also confirmed that these materials were thermally stable as neither phase transition nor weight loss was discernible within the studied temperature range 30–1000 °C. BZCN perovskites were highly insulating with high activation energies in the range ~ 2.51–3.19 eV. At 1 MHz and 30 °C, the recorded dielectric constants and losses were found to be ~ 24–29 and ~ 0.24–0.38, respectively.

Physical, structural, and shielding properties of cadmium bismuth borate-based glasses

We explore a new glassy material for radiation shielding applications. Novel transparent and non-toxic Bi2O3–B2O3 glasses including different concentrations of CdO were prepared by the conventional melt quenching method. The prepared samples were characterized and analyzed by using various analytical tools (XRD, FTIR, Raman, DSC, and UV-Vis-NIR). Ab initio molecular dynamics simulations were carried out to create structural models of the materials, and these were compared to our measurements. To the best of our knowledge, this is the first study to compare the vibrations obtained experimentally with the vibrational density of states obtained from an ab initio computer model for these materials. The radiation shielding properties were measured for the photon energy range (10−3–105 MeV): both mass attenuation coefficient (μ/p) and effective atomic number (Zeff) showed a gradual increase with an increase in the CdO content. The mean-free-path, tenth value layer, half-value layer, and electron density for all prepared glasses were estimated. Promising results were achieved with the new glasses for radiation shielding purposes such as nuclear reactor and medical applications. The structural, electronic, and vibrational properties of the computer models revealed a topologically disordered, but chemically ordered network, and our vibrational computations provide direct insight into several Raman peaks observed for the materials.

Radiation shielding properties of bismuth borate glasses doped with different concentrations of cadmium oxides

The current study is aimed to investigate the gamma ray and neutron shielding properties of the bismuth borate glass system with various concentration of cadmium oxide (0, 5, 10 and 15 mol%). The XRD spectra confirms the amorphous state of the prepared samples. A number of physical and mechanical properties (molar volume, oxygen molar volume, oxygen packing density, Poisson’s ratio, optical absorption and dissolution rates) have been determined. The mass attenuation coefficients were estimated at different energy levels by using XCOM and EXABcal programs. The gamma and neutron beam shielding properties are evaluated through the calculation of several parameters such as equivalent number, specific gamma ray constant, gamma dose rate, specific absorbed fraction of energy and total neutron removal cross-section. Comparing with the standard gamma ray shielding materials, the new composition exhibits promising properties in terms of mass attenuation, halve value layer and mean free path. The glass with the highest concentration of CdO was found to be good shielding material for neutrons compared with some standard shielding materials (water, graphite, ordinary concrete and hematite-serpentine concrete).

Enhanced photocatalytic performance of CdO-WO3 composite for hydrogen production

Considering the renewability and cleanness of hydrogen generation system, the photocatalytic H2 evolution through water splitting with assistance of Earth abundant co-catalysts has become a scientific hotspot. Efficient and visible light driven CdO-WO3 composites with versatile properties have been fabricated through hydrothermal approach for H2 evolution. X-ray diffractometer, scanning electron microscope, UV-Vis absorption spectroscopy, photoluminescence emission spectroscopy and photocatalytic activity test were employed to investigate different properties like crystallography, morphology, optical and photocatalytic properties. The effect of CdO concentration on the grain size indicated the reduction of bad gap energy of the WO3. The concentration of CdO nanoparticles in WO3 directly effect on the morphology of the particles that are in the form of nanorods. The atoms of CdO makes the WO3 nanoparticles more effective and efficient up to 4% of CdO but when coupling amount increases then the CdO-WO3 nanoparticles exhibited less photocatalytic performance to evolve H2 energy. Results shown that 4% content in WO3 had exceptional photocatalytic activity for water splitting when compared to other samples. The improved hydrogen production was allied with formation of active Cd species during the photocatalysis process, which has the ability to promote the interfacial charge-separation and concurrently may cause to reduce the over potential of hydrogen evolution, thus boosting the photocatalytic activity over the hybrid sample. The improved photocatalytic activity of composites could be accredited to extended absorption region of visible light, efficient separation of charge carrier's and suppress recombination of electron-hole pairs. The current work not only shows a prospect for the utilization of low cost CdO as a co-catalyst in photocatalytic hydrogen generation but also shows a substantial enhancement in H2 evolution, first time, using CdO-WO3 hybrid photocatalyst.

Exposure to chemically-dispersed oil is more harmful to early developmental stages of the Northern shrimp Pandalus borealis than mechanically-dispersed oil

Knowledge of key species sensitivity for oil spill response (OSR) options is needed to support decision-making and mitigate impact on sensitive life stages of keystone species. Here, Northern shrimp (Pandalus borealis) larvae were exposed for 24 h to a gradient (H-High, M-Medium: 10 times dilution and L-Low: 100 times dilution) of mechanically- (MDO) (H < 6 mg/L total hydrocarbon content) and chemically- (CDO) dispersed oil (Slickgone NS, H < 20 mg/L total hydrocarbon content), followed by a recovery period. Larval mortality, feeding rate and development were evaluated.Overall, the results show that 24 h exposure to field-realistic concentrations of CDO lead to lower survival, reduced feeding rate and slower larval development in P. borealis larvae compared to MDO. These effects persisted during recovery, indicating a higher vulnerability with dispersant use and the need for longer observation periods post-exposure to fully evaluate the consequences for sensitive life-stages from OSR.

Structural and photoluminescence properties of CdO doped TiO2 thin films prepared by pulsed laser deposition

TiO2 thin films have been deposited at different concentration ofCdO of (x= 0.0, 0.05, 0.1, 0.15 and 0.2) Wt. % onto glass substratesby pulsed laser deposition technique (PLD) using Nd-YAG laserwith λ=1064nm, energy=800mJ and number of shots=500. Thethickness of the film was 200nm. The films were annealed todifferent annealing (423 and 523) k. The effect of annealingtemperatures and concentration of CdO on the structural andphotoluminescence (PL) properties were investigated. X-raydiffraction (XRD) results reveals that the deposited TiO2(1-x)CdOxthin films were polycrystalline with tetragonal structure and manypeaks were appeared at (110), (101), (111) and (211) planes withpreferred orientation along 2Ɵ around 27.30. The results ofphotoluminescence (PL) emission show that there are two peakspositioned are around 320 nm and 400 nm for predominated peakand 620 nm and 680 nm for the small peaks.

The effect of CdO–ZnO nanoparticles addition on structural, electrical and mechanical properties of PVA films

Cadmium oxide doped zinc oxide (CdO–ZnO) nanoparticles were synthesized by solution combustion technique. CdO–ZnO nano particles were used as fillers and their concentration ranged between 0.5% to 2.5% by weight in polyvinyl alcohol (PVA) films. The effect of nano filler concentration on structural, electrical and mechanical properties was investigated. Dielectric constant values decreased upto 1.24 GHz frequency, between 1.24 to 3 GHz frequency range a slight increase in dielectric constant was observed. At frequencies above 500 kHz increase in AC conductivity and loss tangent of the polymer nanocomposites were observed. Enhanced mechanical properties were observed with increase in dopant concentration. A significant increase of 152.65% in film toughness, 113.58% increase in elastic modulus and 83.10% increase in ultimate tensile strength was observed at 2.5 wt% concentration of CdO–ZnO in PVA film as compared to pristine PVA film, which makes CdO–ZnO a desirable reinforcing material for nanocomposites.

Effect of Ag incorporation on structural and opto-electric properties of pyrolized CdO thin films

We have investigated the structure, morphology and opto-electric properties of CdO and Ag-incorporated CdO thin films prepared by chemical spray pyrolysis (CSP) method. The X-ray diffraction (GIXRD) study confirms that CdO samples are highly polycrystalline with cubic structure. The AFM study shows smooth surfaces both for CdO and Ag-CdO thin films. The direct band gap energy varies from 2.25 to 2.50 eV depending on Ag content in the films. Urbach energy reversal in optical band gap indicates that several localized states are present above Fermi level or near at the conduction band. The optical properties, such as refractive index, optical conductivity and nonlinear optical susceptibility, are found dependent on Ag content. A combined effect on the transport properties has been observed with the incorporation of Ag in CdO. The metal-like electric conduction of CdO film has been removed up to a temperature Tc for Ag doping. The n-type carrier concentration of CdO is reduced with increasing Ag content and the concentration is of the order of ~ 1020 cm−3.

Sublethal effects of chronic exposure to CdO or PbO nanoparticles or their binary mixture on the honey bee (Apis millefera L.).

Cadmium and lead-based nanotechnologies are increasingly used in agricultural, industrial, and biological processes; however, potential adverse effects of nanomaterials on honey bees had not been assessed. In this study, effects of exposures to sublethal concentrations of PbO and CdO nanoparticles (NPs), either separately or in combination on honey bee (Apis mellifera) workers, were assessed. Honey bee workers were orally exposed for 9days under laboratory conditions to sublethal concentrations (20% of LC50) of CdO (0.01mg/ml-) and PbO (0.65mg/ml-) NPs either separately or combined. Effects on survival, feeding rate, activity of acetylcholinesterase (AChE), and expression of selected stress-related detoxifying enzymes were quantified. Survival and feeding rates decreased particularly in bees fed sugar syrup containing CdO NPs or binary mixtures of NPs of both metal oxides. Expressions of genes involved in detoxification of xenobiotics were affected by various combinations. Expression of catalase was 13.6-fold greater in bees consumed sugar syrup diet containing binary mixture of sublethal concentrations of both CdO and PbO NPs than it was in unexposed, control bees. AChE activity in heads of honey bees was inhibited by 3.8-, 3.0-, and 2.8-fold relative to control, respectively, in response to exposure to Cd or/and Pb oxide NPs. This result indicates potential neurotoxic effects of these NPs to honey bees. CdO NPs exhibited greater potency to honey bees. Overall, sublethal concentrations of CdO or/and PbO NPs resulted in detrimental effects on honeybee workers.