Cadmium Nitrate Research Articles

CdS sensitized cadmium doped ZnO solar cell: Fabrication and characterizations

Chemical solution deposition of the porous Cd doped ZnO films has been carried out on Indium Tin Oxide (ITO) coated glass substrate. Photosensitization of Cd doped ZnO photo electrode with nanocrystalline CdS is carried out using successive ionic layer adsorption reaction (SILAR) technique. The cadmium nitrate and sodium sulfide anhydrous were used as precursors for Cd2+ and S2−, respectively. The bare ZnO, Cd doped ZnO and CdS sensitized ZnO & Cd:ZnO films were characterized by using scanning electron microscopy, X-ray diffractometry and UV–Vis spectroscopy. The effect of Cd doping and sensitization of CdS on the performance of solar cell was studied by using current-voltage measurement. The enhancement in power conversion efficiency is observed for CdS/Cd:ZnO (0.43%) with that of CdS/ZnO (0.06%) photoanode.

Bioturbation effects on bioaccumulation of cadmium in the wetland plant Typha latifolia: A nature-based experiment

The development of efficient bioremediation techniques to reduce aquatic pollutant load in natural sediment is one of the current challenges in ecological engineering. A nature-based solution for metal bioremediation is proposed through a combination of bioturbation and phytoremediation processes in experimental indoor microcosms. The invertebrates Tubifex tubifex (Oligochaeta Tubificidae) was used as an active ecological engineer for bioturbation enhancement. The riparian plant species Typha latifolia was selected for its efficiency in phyto-accumulating pollutants from sediment.Phytoremediation efficiency was estimated by using cadmium as a conservative pollutant known to bio-accumulate in plants, and initially introduced in the overlying water (20μg Cd/L of cadmium nitrate – Cd(NO3)2·4H2O). Biological sediment reworking by invertebrates' activity was quantified using luminophores (inert particulates).Our results showed that bioturbation caused by tubificid worms' activity followed the bio-conveying transport model with a downward vertical velocity (V) of luminophores ranging from 16.7±4.5 to 18.5±3.9cm·year−1. The biotransport changed the granulometric properties of the surface sediments, and this natural process was still efficient under cadmium contamination. The highest value of Cd enrichment coefficient for plant roots was observed in subsurface sediment layer (below 1cm to 5cm depth) with tubificids addition.We demonstrated that biotransport changed the distribution of cadmium across the sediment column as well as it enhanced the pumping of this metal from the surface to the anoxic sediment layers, thereby increasing the bioaccumulation of cadmium in the root system of Typha latifolia. This therefore highlights the potential of bioturbation as a tool to be considered in future as integrated bioremediation strategies of metallic polluted sediment in aquatic ecosystems.

Sonochemical synthesis and characterization of new seven coordinated zinc, cadmium and mercury nitrate complexes: New precursors for nanostructure metal oxides

The nitrate complexes of group 12 elements with a tridentate Schiff base ligand (L = (E)-N1-((E)-3- phenylallylidene)-N2-(2-((E)-((E)-3-phenylallylidene) amino)ethyl) ethane-1,2-diamine) were synthesized via sonochemical process and characterized by various physical and chemical methods. The structural analysis of the zinc nitrate complex by single crystal X-ray diffraction analysis shows that the central atom is seven-coordinated by three nitrogen atoms from the Schiff base ligand as well as four oxygen atoms from two different nitrate anions. The geometry around the metal center can be described as a distorted pentagonal bipyramid. The crystal packing analysis of zinc nitrate complex indicates that the intermolecular interactions related to nitrate groups plays the essential role in the orientation of supramolecular structure. Hirshfeld surfaces (HS) and their corresponding fingerprint plots (FP) have been also used for further investigation of crystal structure of zinc nitrate complex. Furthermore thermal analyses (TG/DTG) of three nanostructure complexes were carried out and discussed. Finally, direct thermolysis of zinc and cadmium nitrate complexes in air atmosphere led to the production of zinc and cadmium oxide nanoparticles.

Nonlinear optical properties of hybridized CdS/ZnS-PVP sols

Hybrid composites of CdS-core ZnS-shell nanoparticles embedded in polyvinylpyrrolidone (PVP) matrixes have been prepared and characterized. Cadmium sulfide (CdS) nanocrystals were grown in water-propanol-2 solutions containing high-molecular (Ms=1300000) polyvinylpyrrolidone (PVP) at room temperature using cadmium nitrate and sodium sulfide as the cadmium and sulfur sources, respectively. The CdS/ZnS-PVP suspensions have promising optical properties for nanocomposite films based on. Nonlinear optical properties of diluted CdS/ZnS sols were studied at 532 nm and 5 ns laser pulses by using the Z-scan technique. Dependence of the nonlinear-optical coefficients on the CdS weight has been obtained.

Kinetics of the synthesis of ultradisperse cadmium and zinc oxide-like powders in a plasma-solution system

The action of the DC glow discharge on the cadmium and zinc nitrates water solution in the absence of additional reagents and without electrodes-solution contact was shown to result in the production of the solids in the liquid phase. The atmospheric pressure direct current discharge was excited in the ambient air by applying a high direct voltage to two pointed titanium electrodes placed above liquid anode and liquid cathode in the H-shaped cell. The discharge current was varied in the range of 30-70 mA and the initional solutions concentrations were 5 mM. The kinetics of particles formation was studied using turbidimetry and nephelometry methods.

Down-top nanofabrication of binary (CdO)x (ZnO)1-x nanoparticles and their antibacterial activity.

In the present study, binary oxide (cadmium oxide [CdO])x (zinc oxide [ZnO])1–x nanoparticles (NPs) at different concentrations of precursor in calcination temperature were prepared using thermal treatment technique. Cadmium and zinc nitrates (source of cadmium and zinc) with polyvinylpyrrolidone (capping agent) have been used to prepare (CdO)x (ZnO)1–x NPs samples. The sample was characterized by X-ray diffraction (XRD), scanning electron microscopy, energy-dispersive X-ray (EDX), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy. XRD patterns analysis revealed that NPs were formed after calcination, which showed a cubic and hexagonal crystalline structure of (CdO)x (ZnO)1–x NPs. The phase analysis using EDX spectroscopy and FTIR spectroscopy confirmed the presence of Cd and Zn as the original compounds of prepared (CdO)x (ZnO)1–x NP samples. The average particle size of the samples increased from 14 to 33 nm as the concentration of precursor increased from x=0.20 to x=0.80, as observed by TEM results. The surface composition and valance state of the prepared product NPs were determined by X-ray photoelectron spectroscopy (XPS) analyses. Diffuse UV–visible reflectance spectra were used to determine the optical band gap through the Kubelka–Munk equation; the energy band gap was found to decrease for CdO from 2.92 to 2.82 eV and for ZnO from 3.22 to 3.11 eV with increasing x value. Additionally, photoluminescence (PL) spectra revealed that the intensity in PL increased with an increase in particle size. In addition, the antibacterial activity of binary oxide NP was carried out in vitro against Escherichia coli ATCC 25922 Gram (−ve), Salmonella choleraesuis ATCC 10708, and Bacillus subtilis UPMC 1175 Gram (+ve). This study indicated that the zone of inhibition of 21 mm has good antibacterial activity toward the Gram-positive B. subtilis UPMC 1175.

Synthesis of CdO Ultradisperse Powders Using Atmospheric Pressure Glow Discharge in Contact With Solution and the Investigation of Intermediate Products

A new plasma-solution method of the CdO ultradisperse powders synthesis was described. The atmospheric pressure direct current discharge was excited in the ambient air by applying a high direct voltage to two pointed titanium electrodes placed above liquid anode and liquid cathode in the H-shaped cell. The discharge current was 40 mA and the total input power was about 40 W. The action of the DC glow discharge on the cadmium nitrate water solution in the absence of additional reagents and without electrodes-solution contact was shown to result in the production of the solids in the liquid phase. The kinetics of particles formation was studied using turbidimetry and nephelometry methods. Powders’ chemical composition and morphology was obtained using X-ray diffraction spectroscopy (XRD), electron-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), differential-scanning calorimetry (DSC) and scanning electron microscopy (SEM). It was found that as-synthesized powders are not the pure cadmium hydroxide but the mixture of the cadmium nitrate, hydroxy nitrate and hydroxide. Some assumptions regarding the mechanisms and pathway of the chemical processes both under the plasma action on the solution and during the calcination of as-synthesized powders were discussed.

A new two-dimensional polymeric cadmium(II) complex containing dicyanamide bridging ligands.

As part of an exploration of new coordination polymers, a cadmium-dicyanamide complex, namely poly[benzyltriethylammonium [tri-μ-dicyanamido-κ6N1:N5-cadmium(II)]], {(C13H22N)[Cd(C2N3)3]}n, has been synthesized by the reaction of benzyltriethylammonium bromide, cadmium nitrate tetrahydrate and sodium dicyanamide in aqueous solution, and characterized by single-crystal X-ray diffraction at room temperature. In the crystal structure, each CdII cation is coordinated by six nitrile N atoms from six anionic dicyanamide (dca) ligands to furnish a slightly distorted octahedral geometry. Neighbouring CdII cations are linked by dicyanamide bridges to construct a two-dimensional anionic layer coordination polymer. One amide N atom in the bridging dca ligand is disordered over two sites. The cations lie between the anionic frameworks and there are no hydrogen-bond interactions between the cations and anions. The organic cations are not involved in the formation of the supramolecular network.

Synthesis and molecular structure of catena((μ2-4,4,10,10-tetramethyl-1,3,7,9-tetraazaspiro[5.5]undecane-2,8-dione-O,O')- aquadinitratocadmium(II))

A coordination polymer, catena((μ2-4,4,10,10-tetramethyl-1,3,7,9-tetraazaspiro[5.5]undecane- 2,8-dione-O,O')-aquadinitratocadmium(II) {[Cd(C11H20N4O2)(H2O)(NO3)2]} n } (I), has been prepared for the first time from cadmium(II) nitrate and the bicyclic bisurea 4,4,10,10-tetramethyl-1,3,7,9-tetraazaspiro[5.5]undecane-2,8-dione (TTSU). Its molecular structure has been determined (CIF file CCDC no. 903387). Triclinic crystals: space group P1, a = 8.9967(4) A, b = 9.6011(4) A, c = 12.5131(7) A, α = 76.307(4)°, β = 73.465(5)°, γ = 63.310(5)°, V = 918.26(8) A3, ρcalc = 1.789 g/cm3, Z = 2. The Rietveld refinement was carried out at 293 K to confirm the single-phase constitution of the obtained powder sample of I: a = 8.9972(4) A, b = 9.6104(4) A, c = 12.5203(4) A, α = 76.373(3)°, β = 73.485(3)°, γ = 73.485(3)°, V = 919.80(6) A3. A number of lines not corresponding to the main phase and not identified from PDF-2 database are observed on the powder X-ray diffraction pattern. The Rietveld refinement showed that the sample contains 91.4 wt % of the main compound I and 8.6 wt % of the TTSU nitrate admixture. The cadmium atom is coordinated by the O(1) and O(1)i atoms of two molecules of the organic ligand (L) generated by the symmetry operation (i1–x,–y,–z), the O(2)ii atom of the third ligand L molecule bound with the supporting one with the symmetry operation (ii–x,–y,–z), a water molecule, and a bidentate and a monodentate nitrate anions. The coordination number of the cadmium atom is 7, the coordination polyhedron is a distorted pentagonal bipyramid. The Cd···Cd distance is 4.0208 (3) A.

Coordination Polymers with Grinding‐Size‐Dependent Mechanoresponsive Luminescence Induced by π···π Stacking Interactions

Two new coordination polymers {[Zn(L)(dma)]2·H2O}n (1) and {[Cd(L)(H2O)3]·dma·H2O}n (2) {H2L = 5‐[(pyren‐9‐ylmethyl)amino]isophthalic acid, dma = N,N‐dimethylacetamide} were synthesized by the reaction of H2L and zinc(II) or cadmium(II) nitrate in mixed solvents. Single‐crystal XRD analyses show that polymers 1 and 2 have 1D chain structures. Due to the existence of π···π stacking interactions in the crystal structure, 1 exhibits mechanoresponsive luminescence, and the fluorescence color changes from weakly yellow to noticeably greenish yellow after application of external mechanical stimulus. Compound 1 shows grinding‐size‐dependent fluorescent emission.

Effects of cadmium stress on seedlings of various rangeland plant species (Avena fatua L., Lathyrus sativus L., and Lolium temulentum L.): Growth, physiological traits, and cadmium accumulation

ABSTRACTA pot culture experiment was performed to study the effect of cadmium stress (Cd stress) on seedling growth, physiological traits, and remediation potency of Avena fatua, Lathyrus sativus, and Lolium temulentum. The seedlings of these native rangeland plant species were treated with 0, 2, 4, and 6 mM cadmium nitrate concentrations. Based on the results of analysis of variance (p < 0.05), the shoot height, shoot dry weight, root length, root dry weight, root: shoot ratio, total chlorophyll content, soluble sugars, and protein contentof A. fatua, L. sativus, and L. temulentum significantly decreased with increased cadmium concentrations. Generally, translocation factor (TF) and tolerance index (TI) decreased significantly as the concentration of cadmium increased. The maximum TF and TI of studied plants in various concentrations of Cd were observed in L. temulentum followed by L. sativus and A. fatua. The root concentration factor (RCF) values of all studied plants were higher than 1 under different cadmium concentrations. Our results indicate that Lolium temulentum could be labeled as an accumulator of Cd asthe values of TF and RCF are greater than 1. A. fatua and L. sativus showed a potential to be used in the phytoremediation of Cd-contaminated soils.

Modifying Titania Using the Molten-Salt-Assisted Self-Assembly Process for Cadmium Selenide-Quantum Dot-Sensitized Photoanodes.

Sensitizing titania with semiconducting quantum dots (QDs) is an important field for the development of third-generation photovoltaics. Many methods have been developed to effectively incorporate QDs over the surface of mesoporous titania, assembled from the 20–25 nm titania nanoparticles. Here, we introduce a molten-salt-assisted self-assembly (MASA) method to fabricate CdSe-modified mesoporous titania photoanodes. A mixture of ethanol, two surfactants (cetyltrimethylammonium bromide and 10-lauryl ether), silica (tetramethyl orthosilicate) or titania source (Ti(OC4H9)4, acid (HNO3), and cadmium nitrate solution was infiltrated into the pores of mesoporous titania (assembled using Degussa 25, P25) and immediately calcined at 450 °C to obtain mesoporous cadmium oxide–silica–titania (meso-CdO–SiO2–P25) or cadmium titanate–titania (meso-CdTiO3–P25) films. The MASA process is a simple method to smoothly coat or fill the pores of titania with mesoporous CdO–SiO2 or CdTiO3 that can be reacted under an H2Se atmosphere to convert cadmium species to CdSe at 100 °C. Etching of the silica films with a very dilute hydrogen fluoride solution produces mesoporous CdSe–titania (meso-CdSe–P25) electrodes. The method is flexible to adjust the CdSe/TiO2 mole ratio over a very broad range in the films. The films were characterized at every stage of the preparation to demonstrate the effectiveness of the method. The electrodes were also tested in a simple two-electrode solar cell to demonstrate the performance of the electrodes that have a power conversion efficiency of 3.35%.

Divergent topologies in luminescent zinc and cadmium substituted isophthalate coordination polymers constructed from long-spanning dipyridylamide ligand precursors

Hydrothermal reaction of zinc or cadmium nitrate, a 5-position substituted isophthalic acid, and the long-spanning dipyridylamide ligand N,N′-(hexane-1,6-diyl)dinicotinamide (hdn) resulted in coordination polymers whose dimensionalities depend on the nature of the ring substituent and the metal coordination environment. The six new phases were characterized by single crystal X-ray diffraction. {[Zn2(hip)2(H2O)2(hdn)]·2H2O}n (1, hip=5-hydroxyisophthalate) shows a 1D ladder topology with [Zn(hip)(H2O)]n uprights spanned by disordered hdn rungs. {[Zn2(nip)2(hdn)2]·2H2O}n (2, nip=5-nitroisophthalate) displays a 1D ribbon motif with [Zn(nip)]n chains pillared by looped pairs of hdn ligands. [Zn3(tbip)2(nic)2]n (3, tbip=5-tert-butylisophthalate, nic=nicotinate) shows trimeric [Zn3(OCO)2] clusters connected into a 3D 8-connected 42464bcu net by tbip and in situ generated nic ligands. {[Cd2(ip)2(H2O)4(hdn)]·2H2O}n (4, ip=isophthalate) and {[Cd2(tbip)2(H2O)4(hdn)]·H2O}n (5) both show a ladder topology similar to that in 1. {[Cd(mip)(hdn)]·H2O}n (6, mip=5-methylisophthalate) manifests a 2D (4,4) grid topology based on linked dimeric [Cd2(OCO)2] units. Luminescent properties were probed; compounds 4 and 6 showed good ability to detect nitrobenzene in ethanol suspension.

Structure-forming role of heterocyclic compounds in the synthesis of metal-organic frameworks based on cadmium(II)

The influence of heterocyclic compounds on the formation of coordination polymers in the system of cadmium(II) nitrate tetrahydrate and biphenyl-4,4′-dicarboxylic acid is demonstrated. Two new coordination polymers [Cd(H2O)(bpdc)(im)2] (1, bpdc2– is biphenyl-4,4′-dicarboxylate, im is imidazole) and [(CH3)2NH2]4[Cd6(dmf)(bpdc)8]·10DMF (2) were obtained under solvothermal conditions in the presence of imidazole or benzimidazole, respectively. Product 1 has a chain structure, while compound 2 possesses a three-dimensional structure with the hex topology. The obtained compounds were characterized by IR spectroscopy, thermogravimetry, elemental analysis, and powder X-ray diffraction.

A calorimetric and thermodynamic investigation of zinc and cadmium hydrous selenites

A calorimetric and thermodynamic investigation of three hydrous selenites, ZnSeO3·2H2O, ZnSeO3·H2O and CdSeO3·H2O, was undertaken. All three phases were synthesized by mixing of aqueous solutions of zinc and cadmium nitrates, accordingly, and sodium selenite and characterized by XRD powder diffraction, energy dispersive X-ray microanalysis, inductively coupled plasma mass spectrometry and thermal analisys methods. The low-temperature heat capacity of ZnSeO3·2H2O, ZnSeO3·H2O and CdSeO3·H2O were measured using adiabatic calorimetry between 5 and 324K, and the third-law entropies were determined. Values of molar third law entropy Sm°(298K, ZnSeO3·2H2O, cr.)=179±1J·K−1·mol−1, Sm°(298K, ZnSeO3·H2O, cr.)=150±1J·K−1·mol−1, Sm°(298K, CdSeO3·H2O, cr.)=171±1J·K−1·mol−1 were calculated. The expanded uncertainties for Sm° are given at the 0.95 confidence level (k≈2). The enthalpies of formation for ZnSeO3·H2O, ZnSeO3·2H2O and CdSeO3·H2O were determined using H2SO4-solution calorimetry giving ΔfHm° (298K, ZnSeO3·2H2O, cr)=−1238±2kJ·mol−1, ΔfHm°(298K, ZnSeO3·H2O, cr)=−931±2kJ·mol−1, ΔfHm°(298K, CdSeO3·H2O, cr)=−906±2kJ·mol−1. The expanded uncertainties for ΔfHm° are given at the 0.95 confidence level (k≈2). The Gibbs energy of formation for ZnSeO3·2H2O, ZnSeO3·H2O and CdSeO3·H2O at T=298K, 1atm have been calculated on the basis on ΔfHm° and ΔfSm°: ΔfGm°(298K, ZnSeO3·2H2O, cr.)=−1035±2kJ·mol−1, ΔfGm°(298K, ZnSeO3·H2O, cr.)=−790±2kJ·mol−1 and ΔfGm°(298K, CdSeO3·2H2O, cr.)=−768±2kJ·mol−1. The expanded uncertainties for ΔfGm° are given at the 0.95 confidence level (k≈2). Smoothed Cp,m°(T) values between T=0K and T=320K for ZnSeO3·2H2O(cr.), ZnSeO3·H2O(cr.) and CdSeO3·H2O(cr.) are presented along with values for Sm° and the functions [Hm°(T)−Hm°(0)] and [Gm°(T)−Hm°(0)]. These results motivate a re-evaluation of the natural conditions under which selenites, and selenates replace selenides, and sulfides in the oxidation zones of sulfide ore deposits or upon weathering of technologic waste. The values of ΔfG° for ZnSeO3·2H2O, ZnSeO3·H2O and CdSeO3·H2O were used to calculate the Eh–pH diagrams of the Zn–Se–H2O and Cd–Se–H2O, systems. These diagrams have been constructed for the average contents of these elements in acidic waters of the oxidation zones of sulfide deposits. The behavior of selenium, zinc, and cadmium in the surface environment have been quantitatively explained by variations of the redox potential and the acidity-basicity of the mineral-forming medium. Precisely these parameters determine the migration ability of selenium compounds and its precipitation in the form of various solid phases.

Structural and optical properties of thermally reduced graphene oxide for energy devices

Natural intercalation of the graphite oxide, obtained as a product of Hummer’s method, via ultra-sonication of water dispersed graphite oxide has been carried out to obtain graphene oxide (GO) and thermally reduced graphene oxide (RGO). Here we report the effect of metallic nitrate on the oxidation properties of graphite and then formation of metallic oxide (MO) composites with GO and RGO for the first time. We observed a change in the efficiency of the oxidation process as we replaced the conventionally used sodium nitrate with that of nickel nitrate Ni(NO, cadmium nitrate Cd(NO, and zinc nitrate Zn(NO. The structural properties were investigated by x-ray diffraction and observed the successful formation of composite of MO–GO and MO–RGO (, Cd, Ni). We sought to study the effect on the oxidation process through optical characterization via UV-Vis spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy. Moreover, Thermo Gravimetric Analysis (TGA) was carried out to confirm > 90% weight loss in each process thus proving the reliability of the oxidation cycles. We have found that the nature of the oxidation process of graphite powder and its optical and electrochemical characteristics can be tuned by replacing the sodium nitrate (NaNO by other metallic nitrates as Cd(NO, Ni(NO, and Zn(NO. On the basis of obtained results, the synthesized GO and RGO may be expected as a promising material in antibacterial activity and in electrodes fabrication for energy devices such as solar cell, fuel cell, and super capacitors.

Toxicity test and Cd, Cr, Pb and Zn bioccumulation in Phalloceros caudimaculatus

The use of animals as bioindicators has been useful, especially in the evaluation of environmental impact of pollutant discharges in aquatic ecosystems. This study, aims to assess the fish Phalloceros caudimaculatus (known as Guaru) as a heavy metal sbioindicator. LC50 (96h) acute toxicity tests to potassium dichromate salts, cadmium nitrate, lead II nitrate and zinc sulfate, and bioaccumulation of metals such as cadmium, chromium, lead and zinc were conducted. In the bioaccumulation test, for three months standard tanks were used, with different contamination levels above the levels set by local law, a pollution control tank was also set. The following data was obtained in acute toxicity tests LC50 (96h): Potassium dichromate 164.58±18.75mg/L, Cadmium nitrate was 29.5±1.21mg/L, Lead nitrate was 15.5±0.47mg/L and zinc sulfate was 62.8±2.81mg/L. The bioconcentration factor (BCF) maintained the order Zn>Pb>Cd>Cr, where the resulting values were considered high for the four elements ranging from 92.4 (Cr) to 1793.1 (Zn). Based on the test results, the Guaru fish proved resistant to the presence of these metals and a showed a high bioaccumulation rate. Thus, it can be used as a bioindicator of heavy metals.

One-pot molten salt synthesis of CdNb2O6/Cd2Nb2O7 heterojunction photocatalysts with enhanced photocatalytic properties

Abstract CdNb 2 O 6 /Cd 2 Nb 2 O 7 heterojunction photocatalysts were one-pot synthesized by a molten salt method using cadmium nitrate, niobium oxide as raw materials in Li 2 SO 4 - Na 2 SO 4 salt system at 900 °C. The as-synthesized photocatalysts were characterized by X-ray diffraction, scanning electron microscopy, photoluminescence, photocurrent, and UV–vis diffuse reflectance spectroscopy. The experimental results show that CdNb 2 O 6 /Cd 2 Nb 2 O 7 is composed of CdNb 2 O 6 rods and Cd 2 Nb 2 O 7 particles. as-synthesized CdNb 2 O 6 /Cd 2 Nb 2 O 7 composites exhibit enhanced photodegradation performances toward Rodamine and phenol under UV light irradiation compared with pure CdNb 2 O 6 and Cd 2 Nb 2 O 7 . The enhancement in photoactivity can be attributed to the construction of CdNb 2 O 6 /Cd 2 Nb 2 O 7 heterojunction and the typical mixed morphology of CdNb 2 O 6 rods and Cd 2 Nb 2 O 7 particles, which result in the effective separation of photogenerated electron/hole pairs and easy transfer of electrons to the surface through CdNb 2 O 6 rods. Moreover, the dominant active species and the photocatalytic mechanism were discussed in detail.

A novel method for fabrication of CdS quantum dot-sensitized solar cells

In this report, a novel and facile in situ gas–solid reaction method has been developed for the deposition of CdS quantum-dots (QDs) on a mesoscopic TiO2 film. In the approach, cadmium nitrate solution was first coated on mesoporous TiO2 films, and subsequently transformed into CdS QDs (with size about 2–3 nm) by reaction with hydrogen sulfide (H2S) gas generated in a closed container at room temperature. Different from the conventional solution techniques, this method offers new opportunities for rapid and facile deposition of CdS QD-coated TiO2 films without the introduction of the by-products. With the CdS QDs-decorated TiO2 active electrodes, the liquid and solid solar cells were fabricated with power conversion efficiencies (PCEs) of 1.90 and 0.80%, respectively.

Photovoltaic performance of an alternating cold–hot method deposited CdSe thin films

Cadmium selenide (CdSe) thin films were prepared on indium tin oxide substrate by an alternating cold–hot method, in which cadmium nitrate solution was used as a cold deposition solution, while sodium selenite and potassium borohydride mixed solution was used as a hot deposition solution. The influences of the preparation conditions such as the concentration of Cd(NO3)2, the number of deposition cycle and the cycle time, on the photoelectric performance of the sample under simulated sunlight were explored. The results show that the CdSe thin film prepared under the reaction conditions of 0.06 mol/l Cd(NO3)2 at the tenth deposition cycle (30 s per cycle) reaches the highest photovoltage of 0.285 V. Under the simulated solar illumination, the open-circuit voltage and short-circuit currents are 0.419 V and 5.57 mA/cm2, respectively. X-ray diffraction indicates that the strongest diffraction peak at 42.215° of the (111) crystal plane is corresponding to 15.15 nm CdSe nanocrystals. Scanning electron microscopy observation shows that the thickness of the CdSe film is about 200 nm and the size of the spherical and uniformly dispersed nanocrystals is around 50 nm.