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The electrochemical behavior of a synthesized Ru complex (RuL) was investigated at multiwalled carbon nanotubes modified carbon paste electrode. Some special properties of the electrochemical response of this modified electrode are suitable charge transfer rate, repeatability and independance of the pH of the solution. The modified electrode can catalyze the electrochemical oxidation of penicillamine (PA) by a heterogeneous chemical reaction between PA and RuL through catalytic EC’ mechanism. The rate constant of this catalytic reaction was obtained as 1.4×106 M−1 s−1 by chronoamperometry. Because of increasing the anodic current and decreasing the oxidation potential of PA at the prepared modified electrode, this electrode was used as an electrochemical sensor for determination of PA. This sensor can determine the concentration of PA in the wide concentration range of 0.20–750.0 µM with the low detection limit of 80 nM. Simultaneous determination of PA and 6-thioguanine in the presence of catecholamines is the other important advantage of this sensor.

Zirconia nanostructures have been prepared via a facile precipitation route using Zirconium (IV) oxynitrate hydrate and tetraethylenepentamine (TEPA). Here, TEPA was used as novel precipitator to fabricate zirconia nanostructures. The influence of reaction time, dosage of TEPA, and solvent was also examined to control the shape and particle size. Results of this work indicate that these reaction parameters have important impact on the control of shape and grain size of the zirconia. To characterize the as-synthesized nanostructures, techniques such as X-ray diffraction (XRD), ultraviolet–visible (UV–vis) spectroscopy, energy dispersive X-ray microanalysis (EDX), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and photoluminescence (PL) spectroscopy were applied. In addition, the formation mechanism of zirconia nanostructures was discussed.

Pure nanocrystalline zirconia has been successfully synthesized by sonochemical-assisted route from zirconyl nitrate and tetramethylethylenediamine (TMED) as starting materials. Here, TMED for the first time was used as precipitating agent to generate nanocrystalline tetragonal zirconia via a sonochemical-assisted route. The effect of solvent and concentration of TMED on the morphology and crystallite size was studied. It was found that these parameters have significant influence on the morphology and crystallite size of the products. The products were characterized by SEM, UV–vis absorption and TEM images, XRD patterns, PL, FTIR, and EDS spectroscopy.

We report the first detailed study of the characteristics of an octahydro-Schiff base derivative as a new luminophor in the peroxyoxalate chemiluminescence (POCL) system. The effect of reagents on this new POCL system was investigated. In addition, the response surface methodology was used for evaluating the relative significance of variables in this POCL system, establishing models and determining optimal conditions. The quenching effect of some cations and compounds such as Cu2+, Fe3+, Hg2+, imidazole, histidine and cholesterol on an optimized POCL reaction were studied. The dynamic ranges were up to approximaterly 100 and 175 × 10−6 M for Cu2+ and cholesterol respectively. The detection limits were 3.3 × 10−6 m and 2.58 × 10−6 m for Cu2+ and histidine, respectively. In all cases the relative standard deviations were 4–5% (n = 4). Copyright © 2014 John Wiley & Sons, Ltd.

Cadmium sulfide/organic nanocomposites, which were based on long nanowires, were synthesized by a simple reaction between cadmium nitrate and thioglycolic acid (TGA) at room temperature. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected-area electron diffraction (SAED), Fourier transform infrared (FTIR) spectra, and thermogravimetric analysis (TG). The CdS/organic nanocomposites was decomposed into pure wurtzite CdS nanorods through hydrothermal treatment at 190°C. Photoluminescence (PL) spectra were used to study the optical properties of CdS/organic composite and pure CdS. It is found that the emission maximum of the CdS/TGA nanocomposite is significantly blue-shifted, and the intensity is highly enhanced as compared to the luminescence spectrum of the bare CdS nanorods.

Current efficiency of perovskite solar cells has reached 23.7%, which is comparable with silicon solar cells. However commercial development is seriously hindered by the instability of the perovskite, especially under moisture conditions. Therefore it is crucial to gain clear understanding of the mechanism of degradation of organic-inorganic perovskite in order to achieve stable perovskite devices. In this paper, the formation and the degradation of perovskite film on different charge transport layers such as a compact TiO2 layer, compact ZnO layer, and ZnO foil, Si nanowires, and porous Si are studied. In addition, density functional theory studies are carried out to better understand the interaction between the perovskite film and substrates. Experimental and theoretical results are combined to draw more reliable conclusion regarding the degradation mechanism. Most notably, the investigations show that the interaction between the iodine (I) atom in the perovskite layer and substrate determine the stability of perovskite cells. As a result, Si has minimum interaction with I atoms and shows maximum stability, while perovskite film degrades on TiO2 film almost immediately.

Bi2S3 hierarchical columniform structures assembled by nanothorns have been first synthesized by a hydrothermal method through the reaction between bismuth(III) monosalicylate [BiO(C7H5O3)] as the precursor and sodium thiosulfate in H2O at 180 °C without any surfactants. These new Bi2S3 structures were characterized by X-ray diffraction, scanning electron microscopy, ultraviolet–visible spectroscopy, photoluminescence spectroscopy, Fourier transform infrared spectra, X-ray photoelectron spectroscopy, and energy-dispersive x-ray microanalysis. The influences of the synthetic parameters were discussed, and a possible growth mechanism for the formation of these complex structures was proposed. © 2013 Curtin University of Technology and John Wiley & Sons, Ltd.

Fluorescence study of the complexation between uranyl salophen (L) and some common anions in acetonitrile–water (90:10, v/v) solution showed a tendency of L toward acetate ion (AcO−). The fluorescence enhancement of L is attributed to a 1:1 complex formation between L and acetate ion which was utilized as the basis for the selective detection of AcO−. The association constant of the 1:1 complex formation of L–AcO− was calculated as 6.60 × 106. The linear response range of the fluorescent chemosensor covers a AcO− concentration range of 1.6 × 10−7 to 2.5 × 10−5 mol/L, with a detection limit of 2.5 × 10−8 mol/L. L showed a selective and sensitive fluorescence enhancement response toward acetate ion over I3−, NO3−, CN−, CO32−, Br−, Cl−, F−, H2PO4− and SO42−, which was attributed to the higher stability of inorganic complex between acetate and L. Copyright © 2012 John Wiley & Sons, Ltd.

In this work, a highly selective membrane triiodide sensor based on a new charge-transfer complex of bis(2,4-dimethoxybenzaldehyde)butane-2,3-dihydrazone with iodine (Iodide Charge Transfer complex: ICT) as membrane carrier is introduced. The influences of five different solvent mediators on sensitivity and selectivity of the proposed sensor were considered. The best performance was obtained with the membrane composition containing 30% poly (vinyl chloride), 63% DBP, 5% ICT and 2% HTAB. The electrode shows a Nemstian behavior over a very Wide triiodide ion concentration range (1.0 x 10 -7 -1.0 x 10 -2 M), and a detection limit value of 8.0 x 10 M. The effect of pH on the potentiometric response of the sensor was also studied, and it was found that the response of the electrode is independent of the pH of the solution in the pH range of 4.0-10. The proposed sensor has a very fast response time (< 12 s), and good selectivities relative to a wide variety of common inorganic and organic anions, including iodide, acetate, bromide, chloride, fluoride, nitrite, nitrate, sulfite, sulfate, cyanide and thiocyanate. In fact the selectivity behavior of the proposed triiodide ion-selective electrode shows great improvements compared to the previously reported electrodes for triiodide ion. The proposed membrane sensor can be used for at least 6 months without any divergence in the potentials. The electrode was successfully applied as an indicator electrode in the titration of triiodide with thiosulfate ion.

We found that bis(thiophenal) pyridine-2,6-diamine (BPD) can be used as an excellent ion carrier to prepare a gadolinium-selective PVC-based membrane sensor. The use of oleic acid (OA) and potassium tetrakis(p-chlorophenyl borate)(KTKpClPB), as anionic additives, and dibutyl phthalate (DBP), acetophenone (AP) and nitrobenzene (NB), as plasticizing solvent mediators was investigated. The best performance was observed with a membrane having the composition of 30% PVC; 62% BA; 5% BPD; and 3% KTKpClPB. The resulting sensor works well over a relatively wide concentration range (1.0×10−6–1.0×10−1 M) with a Nernstian slope of 19.4±0.4 mV per decade of gadolinium activity over a wide pH range (3.5–8.0). The limit of detection of the sensor is 7.0×10−7 M (ca. 110 ng mL−1). The proposed electrode shows excellent discriminating ability toward gadolinium ions with regard to common alkali, alkaline earth, transition, heavy metal ions, and specially, lanthanide ions. The proposed sensor was applied as an indicator electrode for titration of gadolinium ions with EDTA.

In this work a dysprosium [Dy(III)]-selective solvent polymeric membrane sensor based on N,N-bis(pyrrolidene) benzne-1,2-diamine, poly(vinyl chloride)(PVC), the plasticizer benzylacetate (BA), and anionic site is described. This sensor responds to Dy(III) activity in a linear range from 1.0×10−5 to 1.0×10−1 M, with a slope of 20.6±0.2 mV per decade and a detection limit of 6.0×10−6 M at the pH range of 3.5–8.0. It has a fast response time of

A simple and fast method for the extraction and determination of ppt level of Pb2+ and Cu2+ ions using octadecyl-bonded silica membrane disks modified by a new tetradentates Schiffs base [Bis(2,4-dimethoxy benzaldehyde) ethylen diimine](TDSB) and inductively coupled plasma atomic emission spectrometry is described. Extraction efficiency, and influence of flow rate, pH, type and the least amount of acid for stripping of Cu2+ and Pb2+ from the modified disks and break through volume were evaluated. The maximum capacity of the membrane disks modified by 5 mg of TDSB used was found to be 347 +/- 7 and 470 +/- 6 microg of copper and lead, respectively. The concentration factor is 500 (for 2500 mL water sample and flow rate of 20 mL min(-1)) and detection limit of the proposed method is 12.5 and 150.5 pg/ml for Cu2+ and Pb2+, respectively. The method was applied to the determination of Cu2+ and Pb2+ ions from various water, wastewater, black tea, and hot pepper samples.

A novel chloride PVC-based membrane sensor based on a ruthenium(III) Schiff's base complex, as an excellent neutral carrier, has been developed. The ruthenium complex, in combination with a ketonic plasticizer and a cationic additive led to ISEs with fundamental characteristics, such as slope sensitivity, short response times and selectivity coefficients, which were sufficient for practical applications. The sensor with composition of 30% PVC, 62% benzyl acetate, 5% ruthenium(III) Schiff's base complex and 3% hexadecyltrimethyl ammonium bromide displays near-Nernstian behavior in a wide concentration range (1.0×10−1–3.0×10−6 M with slope of −54.5±0.5) with a detection limit of 2.0×10−6 M (71.0 ng per mL). The response of the electrode is independent on pH in the range of 4.0–10.0 and can it be used for at least ten weeks. The proposed electrode shows a very short response time (

A novel bromide PVC-based membrane sensor, based on iron(III)-salen (IS) as an electroactive material, is successfully developed. The sensor possesses the advantages of low detection limit (6.0×10−6), wide working concentration range (7.0×10−6–1.0×10−1 M), Nernstian behavior (slope of 59.0±0.5 mV per decade), low response time (

Three nickel(II)-hexaazacyclotetradecane complexes were studied to characterize their abilities as perchlorate ion carrier in PVC membrane electrodes. The electrodes based on these complexes exhibit Nernstian responses for ClO over very wide concentration ranges (1.0×10−1 −5.0×10−7 M) with detection limits of 2.0×10−7 −5.0×10−7 M (20–50 ng/mL). The sensors show very good selectivity for ClO ion in comparison with the most common organic and inorganic anions. The responses of the proposed electrodes are independent of pH in the range of 3.5–11.0. The perchlorate selective membranes show fast response time (

A highly selective and sensitive membrane electrode based on vanadyl salen complex (VS), which responds to monohydrogenphosphate (MHP) ions is described. The response of the sensor is Nernstian over the wide concentration range (1.0×10−1 − 5.0×10−6 M) of MHP. The sensitivity of the electrode is high enough to permit the detection of as little as 0.6 μg/mL of MHP without any significant interference from high levels of other anions. The potentiometric selectivity coefficient data revealed negligible interference from 11 common anions. The electrode has a fast response time (

A highly sensitive and selective membrane electrode for the determination of ultra trace amount of nickel was prepared. The PVC membrane electrode based on benzylbis(thiosemicarbazone) which was directly coated on graphite, displays a Nernstian response for Ni2+ ions over a wide concentration range (1.0×10−2−1.0×10−7 M) with a limit of detection of 4.0×10−8 M (ca. 2.4 ppb). It has a fast response time of ca. 15 s and can be used for at least 3 months without observing any major deviation. The electrode revealed a very good selectivity with respect to all common alkali, alkaline earth, transition and heavy metal ions. It was used as an indicator electrode in potentiometric titration of nickel ions and direct determination of nickel in edible oil and wastewater of nickel electroplating samples.

La2(CO3)3·1.7H2O nanoparticles are prepared by sonication of aqueous solutions of Na2CO3 and La(OAc)3.

HgTe rod-shape composed of crystalline particles has been prepared by a hydrothermal method, and characterized by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transition electron microscopy (TEM). The effects of capping agents, reductants, reaction temperatures, and reaction times on crystal structures and shapes of HgTe have been investigated. The results showed that the CTAB as capping agent plays a crucial role in the hydrothermal process. The synthesis procedure is simple and uses less toxic reagents than the previously reported methods.

Studies on complex formation of tris(3-(2-hydroxybenzophenone)propyl)amine (THPA) with a number of metal ions in acetonitrile solution revealed the occurrence of a selective 1 : 1 complexation of the proposed ligand with Sn2+ ion. Consequently, THPA was used as a suitable neutral ionophore for the preparation of a polymeric membrane-selective electrode. The electrode exhibits a Nernstian behavior with a slope of 29.4±0.3 mV per decade and a detection limit of 2.0×10−7 M. It also showed a good selectivity for Sn2+ ions in comparison with some of group A and B metal ions over a wide concentration range of 5.0×10−7–1.0×10−1 M. Improved selectivity was achieved compared to the best selectivity recently reported by other authors for tin(II). The electrode was successfully applied to the determination of Sn2+ ion in waste water and various canned products.