Cadmium Acetate Research Articles

Multifunctional additive CdAc2 for efficient perovskite-based solar cells.

Polycrystalline perovskite films fabricated on flexible and textured substrates often are highly defective, leading to poor performance of perovskite devices. Finding substrate-tolerant perovskite fabrication strategies is therefore paramount. Herein, we show that adding a small amount of Cadmium Acetate (CdAc2 ) in the PbI2 precursor solution results in nano-hole array films and improves the diffusion of organic salts in PbI2 , and promotes favorable crystal orientation and suppresses non-radiative recombination. Polycrystalline perovskite films on the flexible substrate with ultra-long carrier lifetimes exceeding 6 μs are achieved. Eventually, a PCE of 22.78% is obtained for single-junction flexible perovskite solar cells (FPSCs). Furthermore, we find the strategy is also applicable for textured tandem solar cells. A champion PCE of 29.25% (0.5003 cm2 ) was demonstrated for perovskite/silicon tandem solar cells (TSCs) with CdAc2 . Moreover, the un-encapsulated TSCs maintains 109.78% of its initial efficiency after 300 hours operational at 45°C in N2 atmosphere. Our work provides a facile strategy for achieving high-efficiency perovskite-based solar cells. This article is protected by copyright. All rights reserved.

Endophytic Plant Growth-Promoting Bacterium Bacillus subtilis Reduces the Toxic Effect of Cadmium on Wheat Plants.

Heavy metal ions, in particular cadmium (Cd), have a negative impact on the growth and productivity of major crops, including wheat. The use of environmentally friendly approaches, in particular, bacteria that have a growth-stimulating and protective effect, can increase the resistance of plants. The effects of the pre-sowing seed treatment with the plant growth-promoting endophyte Bacillus subtilis 10-4 (BS) on cadmium acetate (Cd)-stressed Triticum aestivum L. (wheat) growth, photosynthetic pigments, oxidative stress parameters, roots' lignin content, and Cd ions accumulation in plants were analyzed. The results showed that the tested Cd-tolerant BS improved the ability of wheat seeds to germinate in the presence of different Cd concentrations (0, 0.1, 0.5, and 1 mM). In addition, the bacterial treatment significantly decreased the damaging effects of Cd stress (1 mM) on seedlings' linear dimensions (lengths of roots and shoots), biomass, as well as on the integrity and permeability of the cell walls (i.e., lipid peroxidation and electrolyte leakage) and resulted in reduced H2O2 generation. The pretreatment with BS prevented the Cd-induced degradation of the leaf photosynthetic pigments chlorophyll (Chl) a, Chl b, and carotenoids. Moreover, the bacterial treatment intensified the lignin deposition in the roots under normal and, especially, Cd stress conditions, thereby enhancing the barrier properties of the cell wall. This manifested in a reduced Cd ions accumulation in the roots and in the restriction of its translocation to the aboveground parts (shoots) of the bacterized plants under Cd stress in comparison with non-bacterized controls. Thus, the pre-sowing seed treatment with the endophyte BS may serve as an eco-friendly approach to improve wheat production in Cd-contaminated areas.

Response of Flavonoids Production to Some Elicitors in Callus and Cell Suspension Culture of Ginkgo (Ginkgo biloba L.)

Aims: This study was conducted to investigate how to maximize the production of flavonoids from ginkgo leaves callus or cell suspension cultures. Study Design: The experiment was implemented in a completely randomized design with 3 replicates. Place and Duration of Study: The study was carried out at the Research Laboratory of Tissue Culture and Preservation of Germplasm, Horticulture Research Institute, Agric. Res. Center, Egypt from 2020 to 2022. Methodology: Adenine sulfate and pyruvic acid were added at concentrations of 0.1, 0.2, and 0.3 mg/l, for each. Cadmium and lead acetate were added (2 and 4 mg/l for each) to the cell suspension. Jasmonic acid (15, 50, and 100 µM), AgNO3 (25, 50, and 75 µM) and tryptophan (50, 100, and 200 mg/l) were used in the hard callus culture. Results: Results indicated that the maximum cell suspension fresh weight (6.50 g) was obtained from (0.5 g) cell suspension grown on MS medium supplemented with adenine 0.2 mg/l while lead acetate at 2.0 mg/l increased dry weight (0.89g) after the second subculture. The maximum packed cell volume (PCV) (24.33%) was obtained from lead acetate at 2.0 mg/l in the second cycle of growth. The best flavonoid production (91.29 mg/100 g DW) was produced in the second cycle of growth from callus treated with AgNO3 at 25 µM. Treating Ginkgo biloba callus cultured with jasmonic acid at 100 µM increased the inhibition of AChE in the serum of AD patients from 235.2 U/l (untreated serum) to 76.08 U/l at 38.71 ug/ml compared with the Ginkgo biloba ® at 260 mg which inhibit the activity from 235.2 U/l to 55.73 U/l at 26.00 ug/ml at amount 25.00 ul for all. Conclusion: Ginkgo biloba is a valuable source of anticholinesterase agents and could be used in pharmaceutical preparations by using callus culture technique treated with jasmonic acid and AgNO3.

Cadmium Sulfide Nanoparticles: Synthesis, Characterization, and Antimicrobial Study

Group II–VI cadmium sulfide nanoparticles (CdS NPs), a potential alternative to antibiotics, were synthesized using cadmium acetate [Cd(Ac)2] as a precursor, sodium sulfate as a reducing agent, and starch as a capping agent through chemical precipitation techniques. The CdS NPs were characterized using different characterizing techniques; X-ray diffraction and selected area electron diffraction patterns verify that the nanoparticles had cubic zinc blende structure with average dimension size of 2.43 nm. Scanning electron mictroscope and transmission electron microscope images illustrated that the particles were uniformly distributed in cluster form, and FTIR and EDX confirmed the synthesized nanoparticles were pure. The CdS NPs show relevant antimicrobial sensitivity against Gram-positive and Gram-negative bacterial strains and the zone of inhibition increases with the increase in the concentration of nanoparticles. In comparison to Gram-positive and Gram-negative bacteria, the synthesized nanoparticles were reported to be more effective toward Staphylococcus aureus, Gram-positive bacteria.

Suberic Acid-Based Supramolecular Metallogels of Ni(II), Zn(II), and Cd(II) for Anti-Pathogenic Activity and Semiconducting Diode Fabrication

The importance of three synthesized metallogels of suberic acid distinctly with nickel, zinc, and cadmium acetate salts has been uncovered. For the creation of these soft materials, N,N'-dimethyl formamide was utilized as a source of the trapped solvent. The synthesized metallogels display intriguing viscoelasticity, and the interpretation of experimental parameters obtained from rheological results advocates the gel behavior. Microstructural analysis combined with energy-dispersive X-ray confirms the occurrence of individual gel-developing constituents as observed in different hierarchical microstructural patterns. Significant variations in microstructural arrangements with diverse extent of supramolecular non-covalent patterns inside gel networks were perceived through field emission scanning electron microscopy, atomic force microscopy, and transmission electron microscopy analyses. Fourier transform infrared and electrospray ionization-mass spectral analyses and powder X-ray diffraction analysis of metallogel samples of different gel-establishing ingredients help to investigate the possible supramolecular interactions dictating the metallogel scaffolds. Thermogravimetric analysis of xerogel samples was collected from the synthesized metallogels to understand the thermal stability. These gel materials were characterized by their potential antibacterial efficiency. The potency of metallogels against selective Gram-positive and Gram-negative bacteria was visualized via a spectrophotometer. Human pathogens like Klebsiella pneumoniae (MTCC 109), Salmonella typhi (MTCC 733), Vibrio parahaemolyticus, Bacillus cereus (MTCC 1272), Lactobacillus fermentum (NCDO 955), and Staphylococcus aureus (MTCC 96) are employed in this study. Apart from the biological significance, our metallogels demonstrate as incredible diode performance of fabricated semiconducting systems, which exhibit a considerable amount of non-linearity demonstrating a non-ohmic conduction mechanism at room temperature in dark conditions. Device fabrication was achieved from these metallogels employing the sandwich model with indium tin oxide-coated glass substrates/metallogel/Al structure.

Bioinspired, Non-Enzymatic, Aqueous Synthesis of Size-Tunable CdS Quantum Dots for Sustainable Optoelectronic Applications.

The enzymatic production of hydrogen sulfide (H2S) from cysteine in various metabolic processes has been exploited as an intrinsically "green" and sustainable mode for the aqueous biomineralization of functional metal sulfide quantum dots (QDs). Yet, the reliance on proteinaceous enzymes tends to limit the efficacy of the synthesis to physiological temperature and pH, with implications for QD functionality, stability, and tunability (i.e., particle size and composition). Inspired by a secondary non-enzymatic biochemical cycle that is responsible for basal H2S production in mammalian systems, we establish how iron(III)- and vitamin B6 (pyridoxal phosphate, PLP)-catalyzed decomposition of cysteine can be harnessed for the aqueous synthesis of size-tunable QDs, demonstrated here for CdS, within an expanded temperature, pH, and compositional space. Rates of H2S production by this non-enzymatic biochemical process are sufficient for the nucleation and growth of CdS QDs within buffered solutions of cadmium acetate. Ultimately, the simplicity, demonstrated robustness, and tunability of the previously unexploited H2S-producing biochemical cycle help establish its promise as a versatile platform for the benign, sustainable synthesis of an even wider range of functional metal sulfide nanomaterials for optoelectronic applications.

Effects of cadmium acetate contaminated drinking water on vital organs: A histopathological and biochemical study.

Cadmium (Cd) is a heavy metal with various human exposure sources. It accumulates in the liver, forming a complex with metallothionein protein and progresses to other organs. As a heavy metal, cadmium can replace calcium and other divalent ions and disturb their cascades, ultimately affecting the vital organs. Since cadmium acetate (CA) is considered more lethal than other Cd compounds, the current study examines the effect of different concentrations of CA doses in drinking water for different exposure times in murine models (Mus musculus). After the exposure period, the murine models were then examined histopathologically and biochemically. The histopathological examination of the heart, liver, and kidneys of the experimental group showed extensive degenerative effects. Atomic absorption spectroscopy was used to determine the quantity of cadmium in serum, kidney, and hepatic tissues. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of hepatic proteins, especially metallothionein, directly related to Cd administration. The biochemical parameters, including creatine kinase, alanine aminotransferase, aspartate aminotransferase, total proteins, glucose, urea, uric acid, and creatinine, were also analyzed. After thorough histochemical and biochemical analysis, it was concluded that even low dose exposure of CA is hazardous to murine models with damaging effects.

Influence of growth time on the properties of CdTe thin films grown by electrodeposition using acetate precursor for solar energy application

Cadmium telluride (CdTe) thin films were deposited using a two–electrode electrodeposition (ED) configuration from an aqueous acidic solution. The electrolyte solution contains 1 M of cadmium acetate dihydrate (Cd (CH3OO) 2.2H2O) as cadmium precursor and 1 ml of tellurium dioxide (TeO2) as tellurium precursor. The thin films were grown for different deposition times of 60, 120, 180, 240, and 300 min to investigate the effect of the deposition period on the structural, optical, electrical, surface morphology, elemental composition, and surface roughness properties of the CdTe thin films in both as–deposited and heat–treated forms. X-ray diffraction (XRD) analysis indicates that the CdTe thin films have polycrystalline cubic zinc blend, orthorhombic and hexagonal structures. The result confirmed that the cubic phase is dominant and the peak for preferred orientation is along the (111) plane. Ultraviolet-visible (UV–vis) spectrophotometry study shows that the band gap of the as-deposited thin films varies from (1.41–1.45) eV, and after heat treatment, the band gap decreased to (1.39–1.42) eV. Photoelectrochemical cell (PEC) measurements show that CdTe thin films haven-type conductivity in both as–deposited and annealed forms. Scanning electron microscopy (SEM) analysis shows that the surface morphology of CdTe thin films changed as the deposition period increases. After heat treatment, increase in grain size was observed. Energy–dispersive x-ray spectroscopy (EDS) analysis shows that the percentage composition of as–deposited and heat-treated CdTe thin films varied with deposition time. After post–deposition treatment (PDT), the concentration of Te decreased, while that of Cd increased due to recrystallization during annealing. For the film deposited for 120 min, stoichiometric composition of CdTe was observed after heat treatment. Scanning probe microscopy (SPM) measurements revealed that the average surface roughness of the thin films varied with deposition time. The maximum average surface roughness was recorded when the film was deposited for 120 min. These results show that the prepared CdTe thin films have potential application as absorber layers in thin film solar cells.

Impact of Polyamide Surface Preparation on the Formation of Mixed CdS-CdTe Layers

CdTe-CdS layers were formed on polyamide (PA) 6 films with different surface modifications using the sorption-diffusion method. Part of the samples of the PA films was boiled in distilled water for 2 h and the other ones were stored in concentrated acetic acid at 20 °C for 0.5 h. After this stage, all the PA 6 films were chalcogenized at 20 °C for 1 or 5 h using an acidified 0.1 mol/L solution of K2TeS4O6. Then, the chalcogenized samples were treated with a 0.1 mol/L solution of cadmium acetate at 70, 80 or 90 °C for 10 min. The elemental and phase composition and the morphological and optical properties of the obtained films were determined. XRD analysis showed that cadmium chalcogenide layers consist of four phases: hexagonal CdTe, orthorhombic CdS, rhombohedral Te and orthorhombic S18. The average crystallite size among the obtained layers was very similar and was in the range of 36–42 nm. The concentrations of cadmium, sulfur and tellurium in the layers on PA 6 and the optical properties of the CdTe-CdS layers were dependent on the method of preparation of the polyamide film, the duration of chalcogenization and the temperature of the Cd(CH3COO)2 solution.

Studies on the Optical Dispersion Parameters and Electronic Polarizability of Cadmium Sulphide Thin Film

Thin film of Cadmium Sulphide (CdS) was deposited onto a precleaned transparent glass substrate by chemical bath deposition technique from a bath containing Cadmium acetate, ammonium acetate, thiourea and ammonium hydroxide. The deposition time was varied from 10 minutes to 50 minutes at an interval of 20 minutes keeping the bath at a constant temperature of using 78HW-1 constant magnetic stirrer. CdS thin film was characterized by UV-Visible spectrophotometer within the wavelength range of 280 nm – 920 nm using Single – Beam Helios Omega UV – VIS spectrophotometer. The optical parameters; extinction coefficient, refractive index and dielectric constant of CdS thin film were analyzed from the absorption spectra and were found to be affected by the deposition time. The optical band gap energy was obtained by Tauc’s equation and were found to decrease from 3.78 eV – 3.70 eV as the deposition time increases. The dispersion parameters (dispersion energy , oscillation energy , moment of optical dispersion spectra and , static dielectric constant and static refractive index ) were calculated using theoretical Wemple-DiDomenico model. The result show that only and behaved differently but other parameters increase as the deposition time increases. The oscillator strength , oscillator wavelength , high frequency dielectric constant and high frequency refractive index were calculated using single Sellmeier oscillator model. While behaved differently other parameters increase as the deposition time increased. Also, Lattice dielectric constant , N/m* and plasma resonance frequency were equally obtained. While decrease with increase in deposition time, N/m* increase with deposition time. The electronic polarizability of CdS thin film was estimated by Lorenz - Lorentz equation and Clausius Mossotti local field polarizability model. The value is an indication that the films showed good response on the application of photon energy. However, its response reduces as the deposition time increases.

Water Content-Controlled Formation and Transformation of Concomitant Pseudopolymorph Coordination Polymers.

Two concomitant pseudopolymorph coordination polymers {[Cd2L2(OAc)4]·2DMSO} n (1) and {[CdL(OAc)2]·2.75H2O} n (2) were synthesized by self-assembly of 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene (L) and cadmium acetate in DMSO. Single-crystal X-ray diffraction confirmed that 1D ladder structural motifs exist for pseudopolymorphs 1 and 2 which contain DMSO and water guest molecules, respectively. Our study illustrated the active role of solvent water content in obtaining compound 2. We find that the presence of water as an impurity in the DMSO solvent creates the possibility of formation of concomitant pseudopolymorph coordination polymers which is a unique event. Furthermore, our analyses showed the effect of environmental humidity on the transformation of unstable compound 1. 1D ladder pseudopolymorphic compound 1 could be transformed to guest-free 1D linear compound [CdL(OAc)2(H2O)] n (3') (the powder form of single crystals of 3) through a scarce case of water absorption from air. Also, the crystalline material of coordination polymer 3 was transformed to coordination polymer 2 through the dissolution-recrystallization structural transformation process in DMF or DMSO. Our study clarified that the amount of water in the reaction container can control the formation of one of the compounds 2 or 3. In the presence of a significant amount of water, compound 3 (coordinated water) will be produced, whereas if a small amount of water is present, compound 2 (uncoordinated water) is prepared as an exclusive product.

Research of the alginate-pectin sorbent influence on the elimination of cadmium from the body of rats

Introduction. Heavy metals have a serious toxic effect on the human body. The availability of adequate models for the elimination of toxicants and the testing of enterosorbents based on them will improve the quality of poisoning therapy. Material and methods. To assess the effectiveness of the sorbent, a formalized model based on data on the cumulative excretion of cadmium in urine and feces for 20 days was used. Intramuscular priming with cadmium acetate was carried out during the first three days of the experiment at a daily dose of 3 mg/ kg, the enterosorbent was administered orally at a dose of 100 mg/kg during the study. The cadmium content in the biological media was determined by methods of inversion voltammetry. Results. During the experiment, no more than 3% of the injected toxicant was removed from the animals of both groups. The enterosorbent in the conditions of the experiment did not change the amount of cadmium excreted, but affected the redistribution between the renal and intestinal elimination streams. A significant effect of the enterosorbent on the cadmium content in the liver was noted. Limitations. Evaluation of the effect of the drug on the elimination of the toxicant was carried out for a limited period of time. Additional experiments with longer observation periods and other metals and their dosages would allow to reveal in more detail the beneficial properties of the studied drug. Conclusion. A significant effect of the enterosorbent on the cadmium content in the liver was noted. There may be a secondary intake of cadmium into the blood from the intestine and a negative effect of this process on kidneys.

Electrodeposition of CdTe thin films using an acetate precursor for solar energy application: The effect of deposition voltage

Cadmium Telluride (CdTe) thin films were synthesized using a low-cost two-electrode electrodeposition configuration in potentiostatic mode and from an aqueous acidic solution. More commonly used cadmium salts for electrodeposition of CdTe include CdSO4, CdCl2 and Cd (NO3)2. In the present work, a less commonly used salt, cadmium acetate, was used as a cadmium precursor for the growth of CdTe thin films. The thin films were deposited on a coated glass fluorine- doped tin oxide (FTO) substrates. The deposition voltage was varied from 1230 to 1270 mV with a 10 mV increment. The structure, optical, conductivity, surface morphological, elemental composition, and surface roughness properties of the as-deposited thin films were investigated by using X-ray diffraction (XRD), UV–VIS spectrophotometry, Photoelectrochemical cell analysis (PEC), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and scanning probe microscopy (SPM), respectively. The XRD results showed that the CdTe thin films displayed a higher intensity at 1250 mV deposition voltage. UV–VIS spectroscopy measurements revealed that the band gap of the CdTe thin films was near that of the bulk CdTe at 1250 mV deposition voltage. The PEC measurement indicated that at a low voltage of 1230 mV, the conductivity of the film was p-type and Te-rich. When the deposition voltage was 1270 mV, the CdTe films became n-type and Cd-rich. EDS results confirmed the presence of both Cd and Te with more stoichiometric values at the growth voltage of 1250 mV. The SEM images showed that the surface morphology changed with deposition voltage. SPM results indicated that the highest average surface roughness value of 94.9 nm was obtained with a deposition voltage of 1250 mV. These results indicate that the film prepared at a deposition voltage of 1250 mV, may have better potential application as an absorber layer in solar cell device.

Binuclear homo- and hetero-metallic complexes containing [(Me3tacn)Ru] units

Reaction of (Me3tacn)RuCl3·H2O and three equivalents of zinc acetate afforded a binuclear heterometallic species (Me3tacn)RuII(µ-Cl)(µ-CH3CO2)2ZnCl (1) (Me3tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane). Treatment of (Me3tacn)RuCl3·H2O with three equivalents of silver triflate or equivalent cadmium acetate in alcohol got trichloro-bridged binuclear homometallic complexes [(Me3tacn)Ru(µ-Cl)3Ru(Me3tacn)]X2 (X = CF3SO3, 2; Cl, 3) with metal–metal Ru-Ru bonds. When three equivalents of manganese acetate and cadmium acetate was employed, such reactions led to isolations of [(Me3tacn)RuIII(µ-O)(µ-CH3CO2)2RuIII(Me3tacn)]2+ species (4/5), with [MnCl4]2− and [CdCl4]2− acting as the counter anions only. The crystal structures of complexes 1–5 have been determined. All complexes have been characterized by infrared, UV–vis spectroscopies and their electrochemical properties were also investigated. Moreover, the catalytic property of ruthenium(III) complexes 4/5 towards oxidation of isopropanol was accordingly investigated.

Investigation on the effect of Potassium on the structural, optical and thermal properties of the L-Threonine Cadmium acetate: Elucidation of organo-cadmium compound for dielectric filters

Investigation on the effect of Potassium on the structural, optical and thermal properties of the L-Threonine Cadmium acetate: Elucidation of organo-cadmium compound for dielectric filters

Unique Mixture of (MgO-CdO) Nanoparticles as an Adsorbent for Water Treatment

Sol- gel method of synthesis of nanomaterials. Sol gel was applied for synthesis of magnesium oxide (MgO) and cadmium oxide (CdO) nanoparticles. Using magnesium nitrate and cadmium acetate as a raw materials and sodium hydroxide as a solvent for hydrated oxide at room temperature. Hydrated Magnesium oxide and cadmium oxide nanoparticles were annealed in air at 600 °C. The characterization methods include examine the morphology of the oxides surface using field emission scanning electron microscopy (FESEM) and Energy Dispersive X-ray spectroscopy (EDX), Characterization of functional groups was performed using Fourier Transform Infrared analysis (FTIR). X-ray powder diffraction (XRD) was used for examine the size of particles using Debye-Scherrer method. MgO and CdO nanoparticles are produced into spherical structures with average crystallite sizes of (55) and (55.5) nm, respectively. The study of using these nanoparticles as adsorbents were done successfully and the high value of removing percentage of iron about 97.8% and 98.7 respectively. Moreover, the mixture of these nano oxides gives 99.2% releasing of iron ion from polluted water.

Hollow CdS-ZnS-ZIF-8 Polyhedron for Visible Light-Induced Cr(VI) Reduction.

By loading a small amount of cadmium acetate dihydrate on the zeolitic imidazolate framework-8 (ZIF-8), a hollow CdS-ZnS-ZIF-8 composite was facilely synthesized by rapid solid-phase grinding with thioacetamide. The evolution of the structure, composition, and photoelectrochemical properties was studied by a series of methods. When it was used as a photocatalyst, the hollow CdS-ZnS-ZIF-8 composite demonstrated a highly visible light response as well as a robust ability and reusability for Cr(VI) reduction, which could be ascribed to the hollow structure and ultrasmall CdS nanoparticles. Notably, the presence of ZIF-8-S (ZIF-8 ground with thioacetamide) could also obviously enhance the stability of CdS by promoting the separation of the photogenerated charge during light irradiation.

Studies on optical and electrical properties of PVA capped nanocrystalline CdSe thin film prepared by chemical bath deposition method

PVA-capped nanocrystalline CdSe thin films are deposited on chemically clean glass substrates by chemical bath deposition technique using Cadmium acetate [Cd(CH3COO)2.3H2O and Sodium Selenosulfate (Na2SeSO3) as Cd2+ and Se2- ions sources respectively. Polyvinyl Alcohol (PVA) is act as a capping agent. Films of five different molarities (0.1 M–0.50M) of same pH value 8 were prepared at room temperature 298 K. The characteristics of the prepared CdSe thin films are investigated in detail by measuring their optical and electrical properties. The band gap energy of 2.16–2.49 eV was determined from the optical absorption spectra. The optical band gap decrease with increase in molarities. The electrical conductivity measured using two co-planar Aluminium electrodes are found to increase with increase in temperature showing semiconducting nature of the films. The electrical conductivity at room temperature is found to be of the order of 10-4 Ω-1 cm-1 .

The shape-controlled synthesis of alloyed CdSxSe1−x nanocrystals and their applications in LEDs

Alloy nanocrystals (NCs) provide access and control of the parameters for nanoscale engineering because their physical and optical properties depend on size, shape, and composition. Here, alloy CdS x Se1−x NCs with different shapes were synthesised via a one-pot method using cadmium acetate, sulfur, and selenium as precursors in trioctylphosphine solution. The luminescence and shapes of NCs were characterised by fluorescence spectroscopy and transmission electron microscopy, respectively. It was found that the modification of precursor concentration resulted in NC shape variation, including branched NCs, long and short nanorods. Consequently, a series of alloy CdS x Se1−x NCs with different shape-based light emitting devices (LEDs) were fabricated and their operation characteristics were also compared. The obtained luminance and luminous efficiency showed that the control of NC shape is the key factor for the improvement of LED performance. We anticipate that this work will provide further insight into the design of CdSxSe1−x NCs-based LEDs with shape variation.

Characterization and whole-genome sequencing of an extreme arsenic tolerant Citrobacter freundii SRS1 strain isolated from Savar area in Bangladesh.

Citrobacter freundii SRS1, Gram-negative bacteria, were isolated from Savar, Bangladesh. The strain could tolerate up to 80 mM sodium arsenite, 400 mM sodium arsenate, 5 mM manganese sulfate, 3 mM lead nitrate, 2.5 mM cobalt chloride, 2.5 mM cadmium acetate, and 2.5 mM chromium chloride. The whole-genome sequencing revealed that the genome size of C. freundii SRS1 is estimated to be 5.4 Mbp long, and the G+C content is 51.7%. The genome of C. freundii SRS1 contains arsA. arsB, arsC, arsD, arsH, arsR and acr3 genes for arsenic resistance; czcA, czcD, cbiN, and cbiM genes for cobalt; chrA, and chrB genes for chromium; mntH, sitA, sitB, sitC, and sitD genes for manganese; and zntA genes for lead and cadmium resistance. This novel acr3 gene has never previously been reported in any C. freundii strain except SRS1. A set of 130 completely sequenced strains of C. freundii were selected for phylogenomic analysis. The phylogenetic tree showed that the SRS1 strain is closely related to the C. freundii 62 strain. Further analyses of the genes involved in metal and metalloid resistance might facilitate identifying the mechanisms and pathways involved in high metal resistance in the C. freundii SRS1 strain.