Characterization Of Cadmium Research Articles

Synthesis and Characterization of Cadmium Ion-Imprinted/Natural Sand Composite and Research on Its Adsorption Properties

Cadmium is a common heavy metal that can cause serious harm to human health, even in trace amounts. Therefore, it is of great significance to develop environmentally friendly, inexpensive, and readily available adsorbent materials with high selectivity. By preparing ion-imprinted composites on the surface of a suitable carrier through surface imprinting, the number of effective adsorption sites can be increased, and target ions can be more quickly identified. In this study, we synthesized a cadmium ion-imprinted/natural sand composite material (NS/Cd-IIP) using natural sand as the carrier, Cd(II) as the template ion, and acrylamide as the functional monomer. A series of characterization techniques were employed to confirm the composite. Static and dynamic adsorption experiments were conducted to investigate various factors affecting its adsorption performance. The optimum adsorption pH was found to be 7, and the adsorption equilibrium time was determined to be 105 min. The imprinted composites exhibited a static adsorption saturation capacity of 33.84 mg·g−1, which was significantly higher than that of the non-imprinted composites. The adsorption behavior of composites followed Langmuir isotherm and quasi-second-order kinetic. Thermodynamic parameters indicated that the adsorption process of NS/Cd-IIP for Cd(II) was exothermic, entropic, and spontaneous. The selectivity of NS/Cd-IIP towards Cd(II) was significantly higher than that towards other ions. By optimizing the dynamic adsorption conditions, the maximum adsorption capacity of NS/Cd-IIP was determined to be 3.77 mg·g−1, and the adsorption behavior conformed to the Thomas model. NS/Cd-IIP was used as a solid-phase extractant for trace determination of Cd(II) in tap water, achieving a recovery rate exceeding 101%.

Preparation and Characterization of Cadmium(II)-Ion-Imprinted Composites Based on Epoxy Resin

In recent years, ion-imprinting technology has been frequently employed to selectively eliminate heavy metals from aqueous solutions. In this study, an environment-friendly porous cadmium-ion-imprinted composite (Cd(II)-IIP) based on epoxy resin was prepared using Cd(II) ion as a template, polyethylene glycol as a porogen, epoxy resin as the carrier, and polyethylene polyamine as complexation agent and curing agent via surface imprinting technique and stepwise polymerization process. Cd(II)-IIP was further characterized using SEM-EDS, FT-IR, TGA, and XPS, the systematic adsorption investigation of Cd(II)-IIP for the Cd(II) ions was explored. The research found that the adsorption capacity of Cd(II) got to the maximum value (qm = 64.74 mg/g) at pH = 4.0 and T = 318 K and the Cd(II)-IIP had high selectivity for Cd(II) in the presence of polymetallic ions and still has good recoverability after five cycles. The results showed that the adsorption process was closer to the pseudo-second-order kinetic model, and the isothermal curves of the experimental data were more consistent with the Langmuir adsorption model, which indicated that the whole process of adsorption was mainly monolayer chemisorption and spontaneous endothermic. In addition, the XPS and FT-IR results indicate that the interaction between Cd(II) and functional groups is related to O or N atoms on Cd(II)-IIP. In summary, Cd(II)-IIP has certain advantages and considerable development prospects for the treatment of wastewater containing Cd(II).

Characterization of Cadmium and Lead Heavy Metals Resistant Fungal Isolates from Ghawar oil field, Saudi Arabia

Contamination of soil with heavy metals is considered the main concern around the world due to dramatic increases in agricultural, industrial, and oil extraction activities. Highly potentials were recorded for fungi, which reflected heavy metal resistant patterns among microflora. Our investigation was carried out for isolating, identifying, and evaluating Cr and Pb resistant capabilities for fungal strains. By using morphological characterization, seventeen fungal strains which reflected resistance against Cr and Pb were identified as Aspergillus, Rhizomucor, Neosartorya, Penicilliumand Rhizomucor , Aspergillus , Penicillium , Cunninghamella and Fusarium for the second site. Among nine microorganisms isolated from the first site which reflected resistant against Cr, Aspergillus flavus reflected highly resistant against all Cr concentrations. Also, Aspergillus Ochraceus and Penicillium oxalicum were resistant to all Cr concentrations except the highest (750 ppm). Only Aspergillus flavus which was isolated from the first site reflected distingushable resistance to all Pb concentrations. Also, A. terreus showed resistant patterns against Cr at 50, 75, 150, and 300 ppm of Pb. At the second site, Aspergillus terreus, Penicillium aurantiogriseum and Aspergillus wentii showed resistant patterns against all Led concentrations. Four selected fungi which reflected resistance against all concentrations of Cr and Pb were identified via 18S rDNA molecular marker and assigned to GeneBank as follows: Aspergillus flavus (OP113794), Aspergillus terreus(OP113795), Penicillium aurantiogriseum (OP113796) and Aspergillus wentii (OP113797).

Synthesis and Characterization of Cadmium with Titanium Oxide (Cd-TiO2) Nanocomposite: Testing its Antibacterial Effect

Sol gel methods were used for the study of the antimicrobial activity of Cd-TiO2 against gram-negative and positive bacteria. These Cd-TiO2 have been characterized by various optical and techniques. They have been exhibited by X-ray diffraction, scanning electron microscopy, ultraviolet spectroscopy, and infrared spectroscopy. The structures of the various XRD patterns indicate that the product has a structure. The particle size of Cd-TiO2 is 35nm. The SEM images confirm the spherical appearance of the sample. The energy X-ray spectra have been confirmed as well and then C, O, Ti, Cd, Pt element are present in Cd-TiO2. The weight percentage of Cadmium is 5.8%, Ti is 51.03%, C is 5.13% and O is 31.75% in Cd-TiO2. BET image shows that the major pore size distribution of Cd-TiO2 is ranged from 2.24 nm. The Cd-TiO2 that the antibacterial activity when tested against the pathogens only gram-negative bacteria such as Pseudomonas. The zone of minimum inhibition concentration was measured in a range of 20mm in 25μl and 30mm in 100μl.

Synthesis and characterization of cadmium and zinc dithiocarbamate complexes derived from α-aminoacid L-proline

Dithocarbamate metal complexes have been used to prepare nanoparticles and nanowires of a variety of semiconducting metals including CdS, ZnS, PbS, and EuS. The two new cadmium (II) L-Proline Dithiocarbamate and zinc (II) L-proline dithiocarbamate complexes have been synthesized. Both of the metal complexes are able to produce semiconductor sulphides, nanoparticles which are applicable in the electronic industries. The amino acid L-proline has the unique property, it is the only DNA determined amino acid which has a secondary five membered cyclic amino group alpha to the carbonyl group in the biosystem. Metal dithiocarbamate which is derived from L-proline is able to produce the corresponding metal sulphides as nanoparticles and nanowire. This is very much applicable in Thin Film Technology. Besides, the Zinc complex is used as a drug in increasing the immune system of the body against bacteria and viruses. Zinc dithiocarbamate derived from alpha aminoacid is biocompatible so that it can be used as pharmaceutical products. The two complexes exhibit the important NCS2 peak from 202.73-215 in 13C NMR, attributing to the presence of the dithiocarbamate ligand. A resonance signal around δ 4.92 is due to COOH-proton in 1H NMR. The complexes also shows the important IR frequencies, ν(CN), ν(CS) and ν(CO) in the ranges 1443-1430 cm-1, 954-945 cm-1 , and 1720-1712 cm-1 , respectively. LMCT transitions have been observed at λ 214 nm for the Cd complex. Based on the thermo gram the complexes are stable up to 200°C, and fast decomposed to produce M(SCN)2 at 400C and finally MS(M= Cd), as residue at 600°C by slow steps. From FTIR, 1H, 13C NMR, only dithiocarbamate sulphurs are coordinated to metal and not the carboxylate oxygen in the two complexes.

Synthesis and characterization of Cadmium (II) complex with tetradentate N2O2- donor Schiff base and biological activity

Synthesis and characterization of Cadmium (II) complex with tetradentate N2O2- donor Schiff base and biological activity

Syntheses and Characterization of Cadmium (II) Oxide Nanostructure from two Nano-sized Cadmium (II) Coordination Polymers

Two nano-sized mixed-ligand Cd (II) coordination polymers; [Cd (4,4' -bpy) (C4H4O4)].1/4 H2O (1) and[Cd(bpy)1.5 (NO3)2].3H2O (2) (bpy=bipiridine) were synthesized by a sonochemical method and characterized by elemental analyses, thermal gravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The crystallinity of these compounds were studied by Powder X-ray diffraction (XRD). CdO nanostructures were obtained by direct calcinations of nano polymers at 400 oC. The cadmium (II) oxidenano-particles were characterized by Powder X-ray diffraction (XRD) and scanning electron microscopy (SEM).

Synthesis and Characterization of Cadmium (II), Lead (II), and Indium (III) Ketoacidoximate Complexes and their Conversion to Metal Oxides

AbstractThe reaction of Cd(II), Pb(II), and In(III) salts with in situ generated pyruvic acid oxime (ketoacidoximate) of the type [O2C‐C(R)=NOH]‐, (R=CH3 or ‐CH2‐C6H5) results in five novel complexes [Cd{O2C‐C(CH2‐C6H5)=NOH}2(py)2]2 (py=C5H5N) 1, [Cd{O2C‐C(CH2‐C6H5)=NOH}2(im)2]2 (im=C3H4N2) 2, [Pb{O2C‐C(CH3)=NOH}2(py)]2 3, [Pb{O2C‐C(CH2‐C6H5)=NOH}2(dmso)]2 (dmso=dimethyl sulfoxide) 4 and (NH4)[In{O2C‐C(CH3)=NOH}4] 5. Single crystal X‐ray structure determination of 1–5 reveal mono‐nuclear In(III) and di‐nuclear, µ2‐oxo bridged Cd(II), Pb(II) complexes. 1–5 undergo thermal decomposition below 210ºC to the corresponding metal oxides.

Characterization of cadmium sulfide/titania heterostructure films by utilizing microstructure and optical characteristics

Engineering and controlling the bandgap of semiconducting metal oxide (TiO2) to enhance photoactivity under visible light is challenging. Impact of the changing CdS thickness (50–150nm) on the structure and optical properties of the CdS/TiO2 heterostructure films (HSFs) which fabricated by pulsed laser deposition (PLD) was observed. XRD, FE-SEM, AFM, UV–vis and PL spectroscopy measurements were utilized to characterize structural and optical behaviors of the films. XRD measurement shows gradual increments of the lattice constants of the films with the increase of CdS thickness. The mean values of the calculated lattice constants and cell volume (V) were a=b=0.3785nm, c=0.9475nm and V=13.58nm3 respectively. The average of crystallite sizes estimated for TiO2 and CdS/TiO2 at various CdS thickness is 12.20, 13.49, 24.24 and 43.10nm. FESEM images prove the high quality nanocrystalline nature of the films without cracks and dislocation. The root means square roughness of the films was increased with the increase of CdS thickness as showed by AFM images. UV–vis measurement reveals an improvement in the optical absorbance of HSFs in the range of 380–550nm due to presence of CdS. Interestingly, the PL intensity was enhanced by a factor of nineteen compare to pure TiO2 attributed to the charge carrier recombination in the band gap. The current results suggest that possibility to improve the optical and structural properties of the TiO2 films and also it possible to fabricate high quality CdS/TiO2 HSFs by variation of the CdS thickness.

Isolation and Characterization of Cadmium- and Arsenic-Absorbing Bacteria for Bioremediation

The contamination of hazardous metal(loid) is one of the serious environmental and human health risks. This study isolated a total of 40 cadmium (Cd)- and arsenic (As)-resistant bacterial isolates from coastal sediments by pour plate technique using tryptic soy agar supplemented with Cd or As (50 mg l−1) for use as metal(loid) bioremediation agents. Out of 40, 4 isolates, RCd3, RCd6, RAs7, and RAs10, showed a relatively higher growth rate in Cd- or As-supplemented culture media which were selected for further study. The selected isolates showed a high minimum inhibitory concentration (60–400 mg l−1 for Cd and 400–2200 mg l−1 for As), which demonstrated their remarkable Cd and As resistance capabilities. The metal(loid) removal efficiencies (0.032–0.268 μg Cd h−1 mg−1 and 0.0003–0.0172 μg As h−1 mg−1 [wet weight cell]) of selected isolates indicated their greater magnitude in absorbing Cd compared to As from water. Phylogenetic analysis of the 16S rDNA sequences revealed that isolates RCd3, RCd6, RAs7, and RAs10 were closely related to Acinetobacter brisouii, Pseudomonas abietaniphila, Exiguobacterium aestuarii, and Planococcus rifietoensis, respectively. Because of high Cd and As resistance and removal efficiency, the selected isolates can survive in a high metal(loid)-contaminated environment and could be a potential tool for bioremediation of high metal(loid)-contaminated effluents to protect the aquatic environment.

Synthesis and characterization of cadmium(II)-imprinted poly(1-allyl-2-thiourea-co-ethylene glycol dimethacrylate) particles for selective separation

The synthesis and characterization of cadmium(II)-imprinted poly(1-allyl-2-thiourea-co-ethylene glycol dimethacrylate) particles are presented. Out of four functional monomers viz. allylurea, 1-vinylimidazole, acrylamide, and 1-allyl-2-thiourea, the last one was selected to produce a novel and selective separation material towards cadmium(II) ions. The energy dispersive X-ray spectroscopy confirmed the presence of monomer residues in the polymer matrix. The optimization of stoichiometry revealed that the highest binding capacity (3.79 ± 0.12 µg/g) and selectivity (imprinting factor of 13.68) were achieved when ion to monomer ratio was equal to 1:1. The structure, morphology and selectivity of imprinted polymer were examined. The imprinted particles possess regular, spherical shape and their surface is highly extended (10.31 ± 0.14 m2/g). The selectivity study towards ions which are present in the real sample showed highest uptake of cadmium(II) ions when compared to lead(II), cobalt(II) or nickel(II) ions with selectivity factors between 2.1 and 2.4.

Characterization of cadmium (108Cd) distribution and accumulation in Tagetes erecta L. seedlings: Effect of split-root and of remove-xylem/phloem

Tagetes erecta has a high potential for cadmium (Cd) phytoremediation. Through several hydroponic experiments, characteristics of 108Cd distribution and accumulation were investigated in T. erecta with split -roots or removed xylem/phloem. The results showed that 108Cd transport from roots to aboveground tissues showed the homolateral transport phenomenon in split-root seedlings. 108Cd content of leaves on the +108Cd side and the −108Cd side was not significantly different, which implied that there was horizontal transport of 108Cd from the +108Cd side to the −108Cd side in cut-root seedlings. Like 108Cd transport, the transport of 70Zn was homolateral. Reduction of water consumption in the removed xylem treatment significantly decreased 108Cd accumulation; whereas, the removed phloem treatment had no significant effect on water consumption, but did decrease 108Cd accumulation in leaves of the seedlings. The removal of phloem significantly reduced distal leaf 108Cd content, which was significantly lower than that in the basal leaves in both the split-root and unsplit-root seedlings. Overall, the results presented in this study revealed that the root to aboveground cadmium translocation via phloem is as an important and common physiological process as xylem determination of the cadmium accumulation in stems and leaves of marigold seedlings.

Partition and characterization of cadmium on different particle-size aggregates in Chinese Phaeozem

Organic-mineral complexations can be isolated from bulk soil by physical disaggregation followed by density fractionation for further examination of the patchy nature of aggregates distributed in soil. Phaeozem, which is a specific regional soil in China with high organic matter, was selected for fractionation into particle-size aggregates with clay, silt, fine sand and coarse sand. Partition and characterization of the adsorbed Cd in the bulk soil and various aggregates of Phaeozem were investigated by Fourier-transform infrared (FTIR) spectrometry, X-ray diffraction (XRD) and sequential extraction. The results indicated that Cd could be differently partitioned into various particle-size aggregates, which could be characterized by FTIR and XRD with the same results. Clay had the highest adsorption capacity for the relevant high content of montmorillonite, kaolinite and chlorite, as well as organic matter and cation exchange capability. The fine fraction had the greatest potential availability and mobility of Cd because it was primarily absorbed on the surface of kaolinite. The texture of Phaeozem likely contributed to the metal fate and behavior in the soil environment, as well as other properties such as organic matter, cation exchange capacity and surface area.

Synthesis, CP-MAS NMR Characterization, and Antibacterial Activities of Glycine and Histidine Complexes of Cd(SeCN)2and Hg(SeCN)2

The synthesis and characterization of cadmium and mercury complexes of selenocyanate of the type [(L)M(SeCN)2] are described, where L is L-Histidine (His) or L-Glycine (Gly) and M is Cd2+ or Hg2+. These complexes are obtained by the reaction of 1 equivalent of respective amino acids with metal diselenocyanate precursor in a mixture of solvents (methanol : water = 1 : 1). These synthesized compounds are characterized by analytical and various spectroscopic techniques such as elemental analysis (EA), IR, H,1 and C13 NMR in solution and in the solid state for C13 and N15. The in vitro antibacterial activities of these complexes have been investigated with standard type cultures of Escherichia coli (MTCC 443), Klebsiella pneumoniae (MTCC 109), Pseudomonas aeruginosa (MTCC 1688), Salmonella typhi (MTCC 733), and Staphylococcus aureus (MTCC 737).

Cadmium(II) and calcium(II) complexes with N,O-bidentate ligands derived from pyrazinecarboxylic acid

The synthesis and characterization of cadmium(II) and calcium(II) complexes with N,O-bidentate ligands derived from pyrazinecarboxylic acid (3-hydroxy-2-quinoxalinecarboxylic acid HL1, pyrazine-2-carboxylic acid HL2) are reported. Obtained compounds [Cd(L1)2(H2O)2](H2O)2 (1), [Cd(L2)2] n (2) and [Ca(L2)2(H2O)4] (3) were studied by elemental analyses, IR, Raman spectroscopy and thermogravimetric methods (TG, DTG, DSC). In addition, the molecular structure of complex 1 has been determined by X-ray single crystal diffraction. Thermal analysis reveals a decomposition process of 1, 3 complexes in multiple stages. The data obtained from TG and DSC curves for 1, 3 confirm not only the presence but also the nature of water (crystallization and coordination) and the stoichiometry of the studied metal complexes. The results of thermal studies are in good agreement with their crystal structures. Thermal behavior of complex 2 indicates a single complete decomposition process of the sample. In addition, complex 2 as a coordination polymer is the most stable all of them and the thermal stability of the obtained complexes can be ordered in the following sequence: 1 < 3 ≪ 2.

Synthesis and Characterization of Cadmium Containing Sodium Borate Glasses

Glass system (80% B2O3 – (20 – y)% Na2CO3 – y% CdO, where y = 3, 6, 9, 12 and 15 mol%) prepared by meltquenching technique and checked by XRD technique reveals the amorphous nature of these glasses. Increases in density from 2.18 to 2.82 (g/cm3) were observed with an increase in CdO content. Ultraviolet-Visible (UV-VIS) absorption spectra of polished parallel surfaces glass samples showed a decrease in the optical band gap from 3.72 to 3.59 eV with increasing CdO content. The results suggest that CdO content in glass samples plays a role as a network modifier. In addition, a correlation between the results from density, UV-VIS and FTIR measurements indicates that change in the atomic structure is due to the formation of BO4 units.

Synthesis, structures, and characterization of cadmium(II), cobalt(II), and copper(II) metal polymers with tetrazole-1-acetate

Three new coordination polymers {[Cd(tza)(2,2′-bpy)(H2O)](ClO4)} n 1, {[Co(tza)(2,2′-bpy)(H2O)](ClO4)} n 2, and {[Cu(tza)(phen)](ClO4)} n 3 (Htza = tetrazole-1-acetic acid, 2,2′-bpy = 2,2′-bipyridyl, phen = 1,10-phenanthroline) were synthesized and characterized by X-ray single-crystal diffraction, elemental analysis, and IR spectra. Complexes 1 and 2 exhibit 3-D architectures formed by π–π interaction of 2,2′-bpy ligands interlinking to the adjacent 2-D layers. Complex 3 is a 1-D zigzag double chain and the 3-D structure is formed by π–π stacking interaction of phen and nonclassical hydrogen bonding.

Synthesis and spectroscopic characterization of cadmium(II) complexes of thiones and thiocyanate

Cadmium(II) complexes of thiones and thiocyanate, [(>C=S)2Cd(SCN)2], have been prepared and characterized by IR and NMR spectroscopy. An upfield shift in the >C=S resonance of thiones in the 13C NMR and downfield shift in N–H resonance in 1H NMR are consistent with sulfur coordination to cadmium(II). The presence of ν(N–H) of thiones in IR spectra of the complexes indicates the thione forms of the ligands in the solid state; some contribution of the thiolate form was observed in one complex. The appearance of a band around 2100 cm−1 in IR and a resonance around 132 ppm in 13C NMR indicates the binding of thiocyanate to cadmium(II).

Coordination modes of 3-hydroxypicolinic acid (OH-picH): Synthesis and characterization of cadmium(II) complexes: Crystal and molecular structures of [CdX(OH-pic)(OH-picH)(H 2O)] 2 X = Cl −, Br −

Two complexes of 3-hydroxypicolinic acid and cadmium(II) chloride and bromide, namely di-μ-halo-[aqua-(3-hydroxypyridine-2-carboxylato- N, O)(3-hydroxypyridinium-2-carboxylato- O)cadmium(II)], halo = Cl − ( 1), Br − ( 2) have been prepared and characterized by spectroscopic, thermal and X-ray crystallographic methods. The IR and thermal data correlate with the structures of the complexes in the solid state. The vibration bands of diagnostic value are compared to the values of the free acid. The complexes 1 and 2 are isostructural. The molecular structures of complexes 1 and 2 comprise centrosymmetrical dimers formed via di-μ-halide bridges. The distorted octahedral cadmium coordination environment contains two halide atoms, one water molecule and two 3-OH-pic ligands, one bonded to the cadmium ion in a monodentate mode through the carboxylate O atom and the other in the bidentate N, O-chelated mode forming a five-membered chelate ring. An extensive network of the O–H⋯O and N–H⋯O hydrogen bonds are found. From 1H and 13C NMR measurements it was determined that in dimethylformamide solution complexes 1 and 2 do not exist. Cd(OH-pic) 2 is the only compound that was identified instead.

Different Coordinative (N, N) and (N, O) Bidentate Behaviour of N‐2‐Pyridyl‐Sulfonamides. Electrochemical Synthesis and Characterization of Cadmium(II) Complexes

AbstractElectrochemical oxidation of cadmium in an acetonitrile solution of N‐2‐pyridyl‐sulfonamides (HL) afforded cadmium coordination compounds of composition [CdL2]. Heteroleptic complexes of composition [CdL2L′] (L′ = 2, 2′‐bipyridine or 1, 10‐phenanthroline) were obtained when the coligand L′ was added to the electrolytic phase. The crystal structures of several compounds have been determined by X‐ray diffraction. In all cases the cadmium atom is hexacoordinated, but the coordinative behaviour of the N‐2‐pyridyl‐sulfonamide ligand depends on the location of the substituents in the pyridyl ring. When the substituent is in position 3, the ligands act as N, O‐donors. In all other cases, the ligands act as N, N′‐bidentate systems.