Hierarchical nanostructures of copper(II) phthalocyanine on electrospun TiO(2) nanofibers: controllable solvothermal-fabrication and enhanced visible photocatalytic properties

In the present work, 2,9,16,23-tetranitrophthalocyanine copper(II) (TNCuPc)/TiO(2) hierarchical nanostructures were successfully fabricated by a simple combination method of electrospinning technique and solvothermal processing. Scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), UV-vis diffuse reflectance (DR), Fourier transform infrared spectrum (FT-IR), X-ray photoelectron spectroscopy (XPS), and thermal gravimetric and differential thermal analysis (TG-DTA) were used to characterize the as-synthesized TNCuPc/TiO(2) hierarchical nanostructures. The results showed that the secondary TNCuPc nanostructures were not only successfully grown on the primary TiO(2) nanofibers substrates but also uniformly distributed without aggregation. By adjusting the solvothermal fabrication parameters, the TNCuPc nanowires or nanoflowers were facilely fabricated, and also the loading amounts of TNCuPc could be controlled on the TNCuPc/TiO(2) hierarchical nanostructural nanofibers. And, there might exist the interaction between TNCuPc and TiO(2). A possible mechanism for the formation of TNCuPc/TiO(2) hierarchical nanostructures was suggested. The photocatalytic studies revealed that the TNCuPc/TiO(2) hierarchical nanostructures exhibited enhanced photocatalytic efficiency of photodegradation of Rhodamine B (RB) compared with the pure TNCuPc or TiO(2) nanofibers under visible-light irradiation.     

A molecular thermometer based on luminescence of copper(II) tetraphenylporphyrin

The photoluminescence (PL) spectra from solid samples consisting of polystyrene and 5,10,15,20-tetraphenyl-21H,23H-porphine copper(II) (CuTPP) revealed two sharp peaks at 653 and 720 nm, and indicated another broad peak at around 780 nm, which could not be observed in CuTPP solutions. The intensity ratio of the two peaks appearing at 653 nm and at around 780 nm demonstrated clear dependence on temperature. This dependence of the PL intensity ratio was observed under the atmosphere and even in water. The findings mean that we were able to utilize PL from CuTPP as a thermometer under various conditions. We measured the temperatures of an organic light-emitting diode (OLED) during operation based on its electroluminescence, where the OLED contained CuTPP as a light-emitting dopant, to demonstrate the CuTPP thermometer.     

Some aspects of reactivity of copper(I) sulphide with copper(II) sulphate

The reaction of Cu₂S with CuSO₄ in SO₂ at T>710 K proceeds forming liquid intermediates, Cu₂SO₂ and Cu₂SO₄, which decompose to solid products. Only SO₂ is a gaseous product out of all the intermediate reactions. The rate of each step is dependent, in a complex way, upon the liquid content of the reacting mixture. The relations of major importance between the rates of individual intermediate reactions, the liquid content of the reacting mixture, the composition of the liquid and the initial composition of the substrates mixtures have been discussed.     

Recovery of cesium ions from aqueous solutions with composite sorbents based on tripolite and copper(II) and nickel(II) ferrocyanides

Uptake of cesium ions from aqueous solutions with tripolite modified with nickel(II) and copper(II) ferrocyanides was studied. The composite sorbent based on tripolite and nickel(II) ferrocyanide exhibits the highest sorption-selective (K _d 1.6 × 10⁴ cm³ g^?1 against the background of 0.1 M NaCl) and kinetic properties among the samples studied. It efficiently takes up cesium ions from aqueous solutions, including salt-containing solutions.     

Study on the instability of organic field-effect transistors based on fluorinated copper phthalocyanine

The effects of positive and negative gate-bias stress on organic field-effect transistors (OFET) based on tantalum (Ta)/tantalum pentoxide (Ta₂O₅)/fluorinated copper phthalocyanine (F₁₆CuPc) structure are investigated as a function of stress time and stress temperature. It is shown that gate-bias stress induces a parallel threshold voltage shift (ΔV_T) of OFETs without changes of field-effect mobility μ_EF and sub-threshold slope (ΔS). The ΔV_T is observed to be logarithmically dependent on time at high gate-bias appropriate to OFET operation. More importantly, the shift is directional, namely, be large shift under positive stress and almost do not move under negative stress. The threshold voltage shift is temperature dependent with activation energy of 0.51 eV. We concluded that threshold voltage shift of the OFET with F₁₆CuPc as active layer is due to charge trapping in the insulator in which trapped carriers have redistribution.     

Determination of copper(II) by displacement substoichiometric extraction with radiolabeled cobalt(II)

A substoichiometric radiochemical displacement technique has been employed for the quantification of trace amounts of copper from complex matrices. The procedure is based on higher stability of copper bipyridine complex compared to its cobalt analog, which leads to the displacement of spiked (⁶⁰Co) cobalt from its bipyridine complex in n-butanol by Cu(II). The amount of labeled cobalt stripped back into the aqueous phase is proportional to the amount of copper incorporated into the organic phase and is monitored for the quantitative estimation of copper. The interferences from various allied ions were critically examined. The proposed method has been successfully employed for the estimation of copper from various certified alloys.     

Prediction of biosorption efficiency for the removal of copper(II) using artificial neural networks

Various low-cost adsorbents have been used for removing Cu(II) ions from aqueous solutions for the treatment of copper containing wastewaters to remove organic compounds and color. Sawdust is an impressive adsorbent in terms of adsorption efficiency, cost and availability; hence the use of sawdust as biosorbent has been widely studied. Many earlier investigations tried to correlate the experimental data with available models or some modified empirical equations, but these results were unable to predict the values of parameters from a single equation. Artificial neural networks (ANN) are effective in modeling and simulation of highly non-liner multivariable relationships. A well-designed and very well trained network can converge even on multiple number of variables at a time without any complex modeling and empirical calculations. In this present work ANN is applied for the prediction of percentage adsorption efficiency for the removal of Cu(II) ions from aqueous solutions by sawdust. Artificial neural network model, based on multilayered partial recurrent back-propagation algorithm has been used. The performance of the network for predicting the sorption efficiency of sawdust for copper is found to be very impressive.     

Optical and photoelectric properties of manganese(II) phthalocyanine epoxy derivative

A novel soluble manganese(II) phthalocyanine (MnPc) epoxy derivative was synthesized and characterized by infrared (IR), electronic absorption spectrum and fluorescence spectrum. Fluorescence quantum yield of the derivative was measured in different solvents and reached 0.35 and 0.39 in dimethylsulfoxide (DMSO) and N, N-dimethylformamide (DMF), respectively. The derivative exhibits high solubility and excellent film-forming property. MnPc epoxy derivative can form cross-linked polymer films without the addition of high polymer. The current–voltage characteristics of films were measured in dark and under infrared irradiation.     

Experimental studies on substituted copper phthalocyanine Langmuir-Blodgett films

Using the Langmuir-Blodgett (LB) technique, novel copper bis(3-hydroxypropyloxy-hexaisopentyloxy)phthalocyanine molecules were deposited on quartz substrates. It is argued on the basis of pressure-area isotherms that films are deposited as monolayers. Optical absorption spectroscopy suggests that the deposited films were uniform. A.c. measurements were performed on LB films in a planar configuration at different temperatures. The power-law dependence of the conductivity on frequency is explained in terms of electronic conduction through hopping over a coulombic barrier 0.66 eV high. The Debye relaxation time is estimated to be of the order 811 µs at room temperature.     

Phase transition in copper(II) pyrovanadate

A new phase Cu₂V₂O₇ synthesized, exhibits phase transitions between 475°C and 500°C. These phase transitions are reversible with ease in contrast toα →β phase transition at 712°C of Cu₂V₂O₇ phase reported earlier. These phase transitions are identified by DTA technique and characterized by detailed XRD investigations at different temperatures. The crystal structures of these Cu₂V₂O₇ phases are related to either thortveitite (Sc₂Si₂O₇) type or a modification of it.     

Phase transitions in copper(II) orthovanadate

Data on the polymorphs of copper(II) orthovanadate are reported. The Cu₃V₂O₈ phase synthesized in this laboratory exhibits phase transitions between 460° and 560°C. These phase transitions are identified through detailed DTA and high temperature XRD techniques; it is observed that these structural transitions are rapid and reversible. The crystal structure of Cu₃V₂O₈ is similar to that of Mg₃V₂O₈, Zn₃V₂O₈, Co₃V₂O₈ and Ni₃V₂O₈.     

Studies on copper(II)- and zinc(II)-mixed ligand complexes of humic acid

Interactions between humic acid (HA), extracted from Brazilian peat soil, and cations of copper(II) and zinc(II) have been examined by infrared spectroscopy, and electrochemical and thermogravimetric analyses. Spectral studies revealed that the interaction with metals occurred mainly at the carboxylic acid groups of HA. The stability constants of HA complexes formed with Cu(2+) and Zn(2+) were found, by square wave voltammetry and application of the Lingane model, to be 8.93 x 10(10) and 2.92 x 10(2), respectively. Thermal analysis indicated that the stability of HA was increased by the presence of divalent cations of copper and zinc.     

Highly efficient fluorescence probe for copper (II) ions based on gold nanoclusters supported on wool keratin

A highly efficient fluorescence gold nanoclusters probe for copper (II) (Cu²⁺) ions among various ions has been prepared through wool keratin as chelating and reducing agent. The main features of fluorescent gold nanoclusters supported on wool keratin (AuNCs@WK) probe are the high fluorescence in aqueous solution, the simplicity of synthesis and the hypotoxicity for living cells. The fluorescence probe exhibits high stability of pHs and shows more sensitivity under acidic condition. Upon exposure to various metal irons, only AuNCs@WK system with Cu²⁺ ions shows a fluorescence turnoff response changing from red to blue under UV light, which lead to the dramatically decreased fluorescent intensity of AuNCs@WK at 690 nm. Moreover, the high sensitivity of AuNCs@WK around 1 µM meets the need of detection standards. The slope of Stern–Volmer plot at low concentration of Cu²⁺ ions is greater than it at high concentrations, which indicates the aggregated AuNCs are from small amounts to large numbers with the increasing concentration of Cu²⁺ ions. The design mechanism of AuNCs@WK probe is the coordination of reactive groups to produce the complex (wool keratin-Cu-wool keratin) at 1:2 between Cu²⁺ ions and fluorescence probe. Furthermore, the cytotoxicity in cells indicates that AuNCs@WK system is safe for the selective imaging of copper ions in living cells.     

MOS dosemeter using bismuth oxide (Bi2O3) and copper phthalocyanine (CuPc) polymer thick film

A metal-oxide-silicon (MOS)-capacitor having an Ag/Bi2O3/CuPc/Ag and an MOS-transistor with Ag (gate)-Bi2O3 (gate insulator)-CuPc (semiconductor)-CdO (drain and source) structure were fabricated using screen-printing polymer thick film. The effects of gamma irradiation on the characteristics of both MOS-capacitor and MOS-transistor were investigated. The flat band voltage (VFB) of the MOS-capacitor showed a shift towards the negative gate voltage when exposed to gamma rays. The IDS-VGS characteristics displayed enhancement mode transistor for such devices. The threshold voltage was found to be 4.25 V, which displayed a linear and gradual decrease in DeltaVT = 0.5 V at VDS = 0 V and DeltaVT = 1.0 V at VDS = 2 V when exposed to gamma rays of dose step of 60 Gy.     

Effect of copper (II) chelate on photodegradation of poly (1-butene)

Photo-oxidative degradation of isotactic poly(1-butene) in the presence and absence of copper (II) bis-(1,3-diphenyl triazine-N-oxide) chelate has been studied, by measuring the weight average molecular weight, measuring changes in the carbonyl groups and by measuring changes in the hydroperoxide contents in the temperature range of 267 to 313 K using monochromatic light of wavelength 253.7 nm. The mechanism leading to the stabilization observed, resulting from the addition of chelate, is discussed.     

On the correlation between morphology and electronic properties of copper phthalocyanine (CuPc) thin films

The morphology of vacuum deposited copper phthalocyanine (CuPc) thin films surface deposited on Si(111) have been studied using the contact mode Atomic Force Microscope (AFM). The influence of substrate temperature during deposition and of the post-deposition UHV annealing on surface roughness as well as on the average and maximum grain height was determined. The observed changes of surface morphology were in a good correlation with the shift of surface Fermi level position in the band gap after O₂ exposure determined in our recent photoemission studies.     

Utilization of copper phthalocyanine and bathocuproine as an electron transport layer in photovoltaic cells with copper phthalocyanine/buckminsterfullerene heterojunctions: Thickness effects on photovoltaic performances

In this work, copper phthalocyanine (CuPc) and bathocuproine (BCP) were used as electron transport layers (ETL) in organic photovoltaic (PV) cells with a structure of indium-tin-oxide/CuPc/C60/ ETL/Al. It was found that PV performance was sensitive to the ETL thickness. A complete coverage of ETL on the C60 film was essential to avoid an insulative C60/Al contact. ETL thickness of 6 nm resulted in optimal PV performance. The PV cells with BCP layers of 2-10 nm demonstrated good PV performance due to efficient electron transport from C60 to Al cathode. Similar result was obtained from the devices with CuPc ETL. However, thicker ETL resulted in considerable lose in PV performance. In both cases, different mechanisms responsible for the dependence of PV performance on ETL thickness are discussed.