Synthesis of nano and micro crystals of Cd(OH)2 and CdO in the shape of hexagonal sheets and rods

Cd(OH)₂ and CdO nano/micro crystals were synthesized in ethanol-water medium using cadmium foil as a source under solvothermal condition. The experimental parameters such as ratio of ethanol to water, concentration of NaOH and synthesis temperature all play important role in determining the size, shape and crystalline phase of the products. The products were characterized by X-ray diffraction and scanning electron microscopy. Nano/micro crystals of CdO were also achieved by thermal treatment of Cd(OH)₂ crystals in air at different temperatures.     

Solvothermal synthesis of Cd(OH)2 and CdO nanocrystals and application as a new electrochemical sensor for simultaneous determination of norfloxacin and lomefloxacin

Cadmium hydroxide (Cd(OH)₂) microcrystals were synthesized in ethanol–water medium by using cadmium chloride as cadmium source and 1,10-phenanthroline as complexation agent under solvothermal condition. The sample was characterized by FT-IR, X-ray diffraction (XRD), scanning electron microscopy (SEM) and TEM. The as-prepared Cd(OH)₂ product were transformed to hexagonal CdO nanocubes by thermal treatment in air at 500 °C. The possible growth mechanism for the formation of different morphologies at basic medium has been proposed. DPV experiments were carried out for the simultaneous determination of norfloxacin and lomefloxacin in the acetate buffer solution with pH 4.5.     

Preparation, conversion, and comparison of the photocatalytic property of Cd(OH)2, CdO, CdS and CdSe

In this paper, we report the hydrothermal preparation of Cd(OH)₂ nanowires and further conversion to CdO nanobelts, CdS nanowires and CdSe nanoparticles through thermal treatment, solvothermal and mixed-solvothermal routes, respectively. The as-obtained products were characterized by means of powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and field emission scanning electron microscopy (FEMSEM). Research showed that four cadmium compounds were good photocatalysts for the degradation of organic dyes such as Safranine T and Pyronine B, under irradiation of 365 nm UV light. The order of catalytic activity of different materials was found to be Cd(OH)₂<CdO<CdS<CdSe.     

Formation of CdO films from chemically deposited Cd(OH)2 films as a precursor

Formation of cadmium hydroxide at room temperature onto glass substrates from an aqueous alkaline cadmium nitrate solution using a simple soft chemical method and its conversion to cadmium oxide (CdO) by thermal annealing treatment has been studied in this paper. The as-deposited film was given thermal annealing treatment in oxygen atmosphere at 450 °C for 2 h for conversion into cadmium oxide. The structural, surface morphological and optical studies were performed for as-deposited and the annealed films. The structural analyses revealed that as-deposited films consists of mixture of Cd(OH)₂ and CdO, while annealed films exhibited crystalline CdO. From surface morphological studies, conversion of clusters to grains after annealing was observed. The band gap energy was changed from 3.21 to 2.58 eV after annealing treatment. The determination of elementals on surface composition of the core-shell nanoparticles of annealed films was carried out using X-ray photoelectron spectroscopy (XPS).     

Colloidal semiconductor quantum dots: Potential tools for new diagnostic methods

We present and discuss the application of colloidal semiconductor quantum dots for diagnostic purposes, with special emphasis for cancer. We prepared and applied core-shell cadmium sulfide-cadmium hydroxide (CdS/Cd(OH)₂) semiconductor quantum dots in aqueous medium. Tissue and cells labeling was evaluated by laser scanning confocal microscopy as well as by conventional fluorescence microscopy. The procedure presented in this work, shown to be a promising tool for fast, low-cost and precise cancer diagnostic protocols.     

Synthesis and characterization of cadmium hydroxide nano-nest by chemical route

A facile chemical route based on room temperature chemical bath deposition (CBD) was developed to deposit the Cd(OH)₂ nano-nest. The growth mechanism follows two-stage crystallization with initial growth of nucleation centers, followed by subsequent anisotropic growth. The nano-nest morphological evolution of Cd(OH)₂ on different substrates has been carried out. These films have been characterized by the techniques; such as X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), optical absorption, contact angle measurement and thermoelectric power (TEP) measurements. The X-ray diffraction study revealed that the as deposited film consists of cadmium hydroxide (Cd(OH)₂) phase. The nano-nest consisted of wires with nearly uniform in dimensions, with diameter around 30 nm and length of few microns. As-deposited Cd(OH)₂ film used in this study showed water contact angle of 66°. The optical bandgap was found to be 3.2 eV, with n-type electrical conductivity as confirmed from thermo-emf measurements.     

Synthesis and separation property of flower-like Cd(OH)2 microstructures via a simple solution route

Well-defined flower-like Cd(OH)₂ microstructures have been successfully synthesized via a simple aqueous solution route, using CdCl₂ and NaOH as the reactants, and triethanolamine (TEA) as the modifying agent. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-vis spectrometer were used to characterize the products. SEM and TEM images illustrated that the flower-like Cd(OH)₂ bundles consisted of hexagonal nanoplates with thickness of about 50 nm. The adsorption of TEA on (0 0 1) plane of the growing Cd(OH)₂ crystal leads to the flower petals in appearance. Further experiments evidenced that the positively charged Cd(OH)₂ could effectively adsorb or separate the negatively charged dye molecules.     

Application of core-shell PEGylated CdS/Cd(OH)2 quantum dots as biolabels of Trypanosoma cruzi parasites

Semiconductor quantum dots are a promising class of materials in the labeling of biological systems. In the present study we show the marking pattern of Trypanosoma cruzi (T. cruzi) live parasites using PEGylated CdS/Cd(OH)₂ fluorescent nanocrystals. The analysis obtained by confocal fluorescence microscopy and transmission electron microscopy indicates that only the endocytic paths of parasites were labeled. The parasites were alive after the incubation with the CdS/Cd(OH)₂-PEG suspension. Labeling the T. cruzi with quantum dots can help to better understand the endocytosis process and also the cellular differentiation.     

Syntheses and characterization of Sr(OH)2 and SrCO3 nanostructures by ultrasonic method

The Sr(OH)₂ and SrCO₃ nanostructures were synthesized by reaction of strontium(II) acetate and sodium hydroxide or tetramethylammonium hydroxide (TMAH) via ultrasonic method. Reaction conditions, such as the concentration of the Sr²⁺ ion, aging time, power of the ultrasonic device and alkali salts show important roles in the size, morphology and growth process of the final products. The pure crystalline SrCO₃ were obtained by heating of product at 400 °C. The Sr(OH)₂ and SrCO₃ nanostructures were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), thermal gravimetric (TG), differential thermal analyses (DTA) and the infrared spectroscopy (IR).     

Synthesis and characterization of dentate-shaped β -Ga2O3 nano/microbelts via a simple method

Dentate-shaped β-Ga₂O₃ nano/microbelts were synthesized successfully via chemical vapor deposition without any other reaction or catalyzer material. The morphology and crystal structure were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) analytic technologies, respectively. The growth mechanism of the products was discussed assisted by the SEM and TEM images. The photoluminescence properties of the β-Ga₂O₃ nano/microbelts have been investigated with a He–Cd laser (325 nm) at room temperature. PACS 81.05.Hd; 81.07.Bc; 81.10.Bk; 81.15.Gh; 81.70.Fy     

Effect of an In-Situ Nucleating Agent on the Polymorphs and Mechanical Properties of Isotactic Polypropylene

The influence of glutaric acid (GA)/cadmium hydroxide [Cd(OH)₂] mixtures on the crystallization and properties of isotactic polypropylene (iPP) was investigated by means of differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), polarized light microscopy, and mechanical tests. It was found that the β-crystalline form was produced in the samples containing 0.15 wt% GA and more than 0.17 wt% Cd(OH)₂. The content of β-crystalline form was maximum, i.e. K_DSC = 65.4% and K_WAXD = 71.4%, when the sample was doped with GA (0.15 wt%)/Cd(OH)₂ (0.20 wt%) (the molar ratio of GA:Cd(OH)₂ was 1:1.2). It was also found that GA/Cd(OH)₂ mixtures not only induced the β-crystalline form but also made spherulites smaller. The results of mechanical tests showed that the toughness of iPP was greatly improved by bicomponent nucleator, while the stiffness decreased a little. Fourier transform infrared spectroscopy analysis indicated that an “in-situ” chemical reaction occurred between GA and Cd(OH)₂ during melt blending, yielding an effective β nucleator (cadmium glutarate).     

Electrochemical capacitive properties of micron-sized chemically grown cadmium oxide discrete crystals

Stable electrochemical capacitive properties of chemically grown cadmium oxide film electrode composed of micron-sized discrete crystals in 1 M Na₂SO₄ electrolyte with a specific capacitance of 1190 mF/g studied over 1000 cycles are reported. Structural and morphological characterizations of micron-sized discrete CdO crystals have been carried out using power X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. Electrochemical capacitive properties of micron-sized CdO discrete crystals on tin-doped indium oxide electrode have been investigated using cyclic voltammetry and chronopotentiometry.     

Sonochemical synthesis of nanoplates of two Cd(II) based metal–organic frameworks and their applications as precursors for preparation of nano-materials

Nano plates of two Cd(II)-based metal–organic frameworks, [Cd₂(oba)₂(4-bpdb)₂]_n·(DMF)_x(TMU-8) and [Cd(oba)(4,4′-bipy)]_n·(DMF)_y (TMU-9) were synthesized via sonochemical reaction by using various time and concentrations of initial reagents and power of irradiation and characterized by scanning electron microscopy, X-ray powder diffraction and IR spectroscopy. Moreover, the effect of triethylamine on speed of nucleation during the synthesis was investigated. Thermolysis of these MOFs at 550 °C under air atmosphere yields CdO nanoparticles.     

Spray deposition of highly transparent fluorine doped cadmium oxide thin films

The cadmium oxide (CdO) and F:CdO films have been deposited by spray pyrolysis method using cadmium acetate and ammonium fluoride as precursors for Cd and F ions, respectively. The effect of temperature and F doping on the structural, morphological, optical and Hall effect properties of sprayed CdO thin films was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), optical absorption and electrical measurement techniques. TGA and DTA studies, indicates the formation of CdO by decomposition of cadmium acetate after 250 °C. XRD patterns reveal that samples are polycrystalline with cubic structure and exhibits (2 0 0) preferential orientation. Considerable broading of (2 0 0) peak, simultaneous shifting of corresponding Bragg's angle have been observed with respect to F doping level. SEM and AFM show the heterogeneous distribution of cubical grains all over the substrate, which are randomly distributed. F doping shifts the optical gap along with the increase in the transparency of CdO films. The Hall effect measurement indicates that the resistivity and mobility decrease up to 4% F doping.     

Low temperature deposition of TiO2 thin films on polyvinyl alcohol fibers with photocatalytical and antibacterial activities

Fine particles of photoactive anatase-type TiO₂ coated polyvinyl alcohol (PVA) fibers (TiO₂/PVA) were prepared successfully via a simple dip-coating method. Tetrabutyl orthotitanate (TBOT) was hydrolyzed in presence of hydrolysis control agent tetrabutylammonium hydroxide (TBA)OH and the TiO₂ fine particles were crystallized under microwave (MW) irradiation. The X-ray diffraction (XRD) and selected-area electron diffraction (SAED) analyses indicated that the fine particles obtained with MW irradiation have much higher crystallinity with a single phase anatase compared with the non-MW-treated solution. The continuous layers of titania were found on PVA fibers by the scanning electron microscopy (SEM) analysis. The fibers with anatase coatings showed high photocatalytic property on the photodegradation of methylene blue (MB) and high antibacterial activity.     

Synthesis,characterization and photoluminescence of ZnO:Cd rosette-like nanostructures using solution process

Well crystalline undoped and Cd-doped ZnO rosette-like structures were successfully synthesized at low temperature (80 °C) via solution process technique during 30 min. Zinc nitrate, cadmium nitrate, sodium hydroxide and hexamine were used as starting materials. The morphology and microstructure were determined by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX) and photoluminescence (PL) spectroscopy. X-ray diffraction indicated that the structure has a single phase with wurtzite structure. FESEM indicated that rosette like structures have been formed. This rosette consists of nanorods with length 210 and 460 nm and diameter 50 and 74 nm for undoped and Cd doped ZnO, respectively. HRTEM showed a decrease in the lattice parameter after the Cd doping. EDX showed that the amount of Cd incorporated into ZnO is 6.4 wt.%. Photoluminescence measurements taken on both doped and undoped samples showed that, in the Cd-doped ZnO nanostructures, the band-edge UV emission is blue shifted and the broad green emission intensity decreased.     

Thermal Reaction Characteristics of Nano/Micron-Sized Aluminum Mixtures in Carbon Dioxide

Thermal reaction characteristics of nano/micron-sized aluminum mixtures in a carbon dioxide atmosphere were investigated by thermogravimetry that aimed to examine the interactions between nanosized aluminum powder and micron-sized aluminum powder. Thermal reaction characteristics of nano/micron-sized aluminum mixtures at different ratios were studied. The synergistic effect mechanism was discussed by comparing experiment result and theoretical calculation. The morphologies and compositions of products were obtained by scanning electron microscopy and X-ray diffraction technologies. Results indicated that there were three weight gain stages for nano/micron-sized aluminum mixtures at different ratios. Although the temperature range of synergistic effect of nano/micron-sized aluminum mixtures with various ratios had somewhat differences, there was a significant synergistic effect from about 900 to 1040°C. The products analyses indicated that the products morphologies of nano/micron-sized aluminum particles showed molten and stuck together, and products contained aluminum and α-Al₂O₃.     

Structural and optical properties of chemically synthesized monodispersed CdCr2S4 films

Alkaline chemical synthesis of amorphous CdCr₂S₄ (CCS) thin films of different thicknesses using cadmium chloride, chromic acid, disodium salt of ethylenediaminetetra acetic acid and thiourea precursors is reported, and the structural and surface morphological properties of CCS using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and transmission electron microscopy (TEM) techniques are discussed. Films of aggregated grains with some void spaces are obtained. Change in band gap energy and electrical resistivity of CCS films are discussed as a function of film thickness. n-type conductivity is confirmed from the sign of thermally generated voltage across the cold and hot junctions.     

溶剂热法制备Cd(OH)_2和CdO纳米盘研究性实验

利用溶剂热法设计了合成Cd(OH)2和CdO纳米盘的研究性实验.以Cd(CH3COO)2等为镉源,与NaOH在水和乙二醇的混合溶剂中反应得到Cd(OH)2纳米盘(中间镉产物),后在高温下煅烧中间产物分解得到CdO纳米盘.该实验有助于理解溶剂热法中各实验参量的作用以及如何通过调节各实验参量最终得到目标产物.     

Synthesis and characterisations of Au-nanoparticle-doped TiO2 and CdO thin films

In the present study, pure and gold nanoparticle (Au NP)-doped titanium dioxide (TiO₂) and cadmium oxide (CdO) thin film were prepared by the sol–gel method, and the effect of Au NP doping on the optical, structural and morphological properties of these thin films was investigated. The prepared thin films were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM) and ultraviolet–visible–near infrared (UV–Vis–NIR) spectra. While the optical band increases from 3.62 to 3.73 for TiO₂ thin films, it decreases from 2.20 to 1.55 for CdO thin films with increasing Au doping concentration. Analysis of XRD indicates that the intensities of peaks of the crystalline phase have increased with the increasing Au NP concentrations in all thin films. SEM images demonstrate that the surface morphologies of the samples were affected by the incorporation of Au NPs. Consequently, the most significant results of the present study are that the Au NPs can be used to modify the optical, structural and morphological properties of TiO₂ and CdO thin films.