(Ba(x)La(1-x)(2))In(2)O(5+x) (0.4 < or = x < or = 0.6) electrolyte-supported mixed-potential CO sensors

The dense (Ba(x)La(1-x)(2))In(2)O(5+x) electrolytes with different compositions (x = 0.4, 0.5, 0.6) were synthesized by Pechini method. The obtained sintered (Ba(x)La(1-x)(2))In(2)O(5+x) electrolytes showed a high relative density of approximately 98%, and the major phase of three electrolyte compositions was indexed as a cubic phase. The CO sensing properties of as-fabricated planar-type (Ba(x)La(1-x)(2))In(2)O(5+x)-based sensors coupled with ITO and Pt as the sensing electrode and reference electrode, respectively, were investigated. The effects of factors such as gas flow rate, chemical compositions, and density of the electrolytes on the sensing performance were investigated. The sensors showed good sensitivity to different concentrations of CO from approximately 100 to approximately 500 ppm and excellent selectivity over low concentrations of methane (<500 ppm). Linear relationships between emf of the sensors and CO gas concentrations from approximately 100 to approximately 400 ppm were observed. However, the sensors indicated more sluggish response compared with the sensors coupled with a corresponding porous electrolyte. The probable reason has been discussed. The long-term stability of the sensor for the detection of CO was also investigated, which indicated a reasonably stable sensor signal after an initial decline during the incubation period.     

Nanosized cation-deficient Fe-Ti spinel: a novel magnetic sorbent for elemental mercury capture from flue gas

Nonstoichiometric Fe-Ti spinel (Fe(3-x)Ti(x))(1-δ)O(4) has a large amount of cation vacancies on the surface, which may provide active sites for pollutant adsorption. Meanwhile, its magnetic property makes it separable from the complex multiphase system for recycling, and for safe disposal of the adsorbed toxin. Therefore, (Fe(3-x)Ti(x))(1-δ)O(4) may be a promising sorbent in environmental applications. Herein, (Fe(3-x)Ti(x))(1-δ)O(4) is used as a magnetically separable sorbent for elemental mercury capture from the flue gas of coal-fired power plants. (Fe(2)Ti)(0.8)O(4) shows a moderate capacity (about 1.0 mg g(-1) at 250 °C) for elemental mercury capture in the presence of 1000 ppmv of SO(2). Meanwhile, the sorbent can be readily separated from the fly ash using magnetic separation, leaving the fly ash essentially free of sorbent and adsorbed mercury.     

Influence of Zn2+ Doping on CaFe2O4 Spinel Ferrites: An Analysis of Experimental Charge Density and Magnetism

Journal of Superconductivity and Novel Magnetism - Single-phase, nanocrystalline Zn2+ substituted cubic spinel CaFe2O4 with the composition ZnxCa1-x Fe2O4 (x?=?0.0, 0.05, 0.1, 0.15) was...     

Sorption of Radionuclides onto Cerium(IV) Hydrogen Phosphate Ce(PO4)(HPO4)0.5(H2O)0.5

Radiochemistry - The ability of cerium(IV) hydrogen phosphate Ce(PO4)(HPO4)0.5(H2O)0.5 to adsorb radionuclides was studied. The degree of sorption from aqueous solutions exceeds 95% at pH &gt;...     

Defluoridation from aqueous solutions by nano-alumina: characterization and sorption studies

The present study was conducted to evaluate the feasibility of nano-alumina (Al(2)O(3)) for fluoride adsorption from aqueous solutions. The nature and morphology of pure and fluoride-sorbed nano-alumina were characterized by SEM with EDX, XRD, and FTIR analysis. Batch adsorption studies were performed as a function of contact time, initial fluoride concentration, temperature, pH and influence of competing anions. Fluoride sorption kinetics was well fitted by pseudo-second-order model. The maximum sorption capacity of nano-alumina for fluoride removal was found to be 14.0 mg g(-1) at 25°C. Maximum fluoride removal occurred at pH 6.15. The fluoride sorption has been well explained using Langmuir isotherm model. Fluoride sorption was mainly influenced by the presence of PO(4)(3-), SO(4)(2-) and CO(3)(2-) ions.     

Physical and chemical modification of distillery sludge for Pb(II) biosorption

The waste distillery sludge from sugar-cane industry was pretreated physically (boiled, heated and autoclaved) as well as chemically (HCl, H(2)SO(4), H(3)PO(4), NaOH, Ca(OH)(2), Al(OH)(3), C(6)H(6), HCHO, CH(3)OH and C1(2)H(25)OSO(3)Na (sodium dodecyl sulphate (SDS)) for assessing the comparative sorption capacity of untreated and modified distillery sludge for Pb(II) biosorption from aqueous solutions. Experiments were conducted in shake flasks on a batch basis to access the effect of different experimental parameters such as pH, biosorbent dosage, biosorbent size, initial Pb(II) concentration and contact time. The uptake capacity 'q' (mg/g) of untreated and pretreated distillery sludge was in following order: NaOH (51.29+/-1.21)>HCl (49.82+/-1.22)>HCHO (49.56+/-1.14)>H(2)SO(4) (47.71+/-1.20)>HgCl(2) (45.32+/-1.06)>Ca(OH)(2) (44.01+/-1.18)>MeOH (43.73+/-1.23)>C(6)H(6) (42.72+/-1.19)>H(3)PO(4) (42.01+/-1.17)>SDS (40.87+/-1.27)>autoclaved (40.23+/-1.24)>Boiled (39.95+/-1.19)>heated (38.87+/-1.32)>Al (OH)(3) (38.30+/-1.14)>untreated (37.76+/-1.21). In further parameter studies, the optimized biosorbent size was 0.250 mm at pH 5 and best dose was 0.05 g of biosorbent. The applicability of the Langmuir and Freundlich models for sorption process was tested and best fitted model was Langmuir with the coefficient of determination (R(2)) value, 0.97, the process followed second order kinetic mechanism.     

Monitoring of a calcination reaction of high reflective green-black (HRGB) pigments by using near-infrared electronic spectroscopy: calcination temperature-dependent crystal structural changes of their components and calibration of the extent of the reaction

This paper demonstrates the potential of near-infrared (NIR) electronic spectroscopy in nondestructive monitoring of a chemical reaction of inorganic functional material. For this purpose NIR spectra in the 12,000-4000 cm(-1) region were measured for high reflective green-black (HRGB) pigments (Co(0.5)Mg(0.5)Fe(0.5)Al(1.5)O(4)) calcined at 1000, 1100, and 1200 °C and pigments with the same components as HRGB but calcined at different temperatures (500-900 °C) (hereafter, called "Pigments A") . NIR spectra of their components such as Co(3)O(4), MgO, Fe(2)O(3), and Al(2)O(3) were also measured. The NIR spectra of Pigments A show two major broad bands. One arises from a (4)A(2)→(4)T(1) (T(h)) d-d transition of Co(II) in the 9000-6000 cm(-1) region. The other band in the 12,000-9000 cm(-1) region is assigned to a foot of the charge-transfer (CT) band of Fe(2)O(3). The Co(II) band contains three component bands that are characteristic of a spinel structure. A shoulder arising from (A(1-x)B(x))(Th)(A(x)B(2-x))(Oh)O(4) (A≡Co, Mg, B≡Fe, Al; inverse spinel structure) emerges near 5900 cm(-1) in the spectra of Pigments A calcined in the temperature range of 700-900 °C, indicating that the Pigments A calcined in this temperature range assume an inverse spinel structure. When the calcination temperature is above 1000 °C, the final product, HRGB, is produced. This is confirmed from the fact that HRGB shows peaks characteristic of a spinel structure that have different wavenumbers from those of the corresponding peaks of Pigments A. Wide-angle X-ray diffraction (WAXD) patterns were also measured for HRGB, Pigments A, and their components. Based on the NIR and WAXD data we investigated calcination-temperature-dependent crystal structural changes of the components. We also developed partial least squares (PLS) calibration models for the 9000-6000 cm(-1) region of the NIR spectra of HRGB and Pigments A. The score plot of latent variable (LV) 2 of the calibration model for calcination temperature demonstrates clearly the existence of an intermediate of the calcination reaction, which may be (A(1-x)B(x))(Th)(A(x)B(2-x))(Oh)O(4) (A≡Co, Mg, B≡Fe, Al).     

Relations between temperature coefficients of permittivity and elastic compliances in PZT ceramics near the morphotropic phase boundary

Variations of temperature coefficients of permittivity epsilon(33)(T), elastic compliances at constant electric fields s(11)(E), and constant polarization s(11)(P) with a Zr/Ti ratio of Pb(Zr(x)Ti(1-x))O(3) and Pb[(Sb(1/3)Mn(2/3))(0.05)Zr(x)Ti (0.95-x)]O(3) solid solutions, were investigated. Relations between temperature coefficients of epsilon(33)(T ), S(11)(E), and S(11) (P) were theoretically derived; a discrepancy was found between theoretical relations and experimental results. On the basis of the observed discrepancy, it is proposed that some extrinsic effects arising from the motion of interphase boundaries between the tetragonal and the rhombohedral phases which exist in grains contribute to values of both elastic compliances.     

Electromechanical properties of fine-grain, 0.7 Pb(Mg(1/3)Nb(2/3))O3-0.3PbTiO3 ceramics

A fine grain, relaxor-based piezoelectric ceramic 0.7 Pb(Mg(1/3)Nb(2/3))O3-0.3PbTiO3 (PMN-30% PT) has been investigated, which was fabricated using the columbite precursor method. The complete set of electromechanical properties of the piezoceramic at room temperature is determined using a combination of ultrasonic and resonance techniques. This fine-grain ceramic (grain size < or = 2.5 microm) exhibits ultra-high dielectric permittivity (epsilon33(T)/epsilon0 approximately 7000) and a high coupling coefficient k(33) (= 0.78). Ultrasonic spectroscopy was used to measure the dispersion of the phase velocity and attenuation for the longitudinal wave propagating in the poling direction. Lower attenuation and smaller velocity dispersion were observed compared to modified Pb(Zr(x)Ti(1-x)O3 (PZT-5H) ceramics. The measurement results show that this fine-grain PMN-30% PT ceramic is a very good material for making ultrasonic array transducers.     

Dumbbell-like PtPd-Fe(3)O(4) Nanoparticles for Enhanced Electrochemical Detection of H(2)O(2)

Dumbbell-like Pt(x)Pd(100-x)-Fe(3)O(4) nanoparticles (NPs) were synthesized and studied for electrocatalytic reduction and sensing of H(2)O(2). In 0.1 M phosphate buffered saline (PBS) solution, the 4-10 nm Pt(x)Pd(100-x)-Fe(3)O(4) NPs showed the Pt/Pd composition-dependent catalysis with Pt(48)Pd(52)-Fe(3)O(4) NPs having the best activity. The Pt(48)Pd(52)-Fe(3)O(4) NPs were tested for H(2)O(2) detection, and their H(2)O(2) detection limit reached 5 nM, which was suitable for monitoring H(2)O(2) generated from Raw 264.7 cells. These dumbbell-like PtPd-Fe(3)O(4) NPs are the most sensitive probe ever reported and can be used to achieve real-time quantitative detection of H(2)O(2) in biological environment for biological and biomedical applications.     

Synthesis and self-assembly of ultrathin Ni(x)Fe(1-x)(OH)2 nanodiscs via a wet-chemistry method

Self-assembled ultrathin Ni(x)Fe(1-x)(OH)2 nanodiscs have been synthesized by using a wet-chemistry method. The uniformity and the assembly of Ni(x)Fe(1-x)(OH)2 nanostructures are sensitive to the iron ion concentration in the precursor. An optimum iron concentration of 10% results in the formation of uniform ultrathin Ni(x)Fe(1-x)(OH)2 nanodiscs with a typical side length of 50 nm and a thickness of 10 nm. They are also self-assembled by connecting their (001) facets with in-plane orientation and form a chain-like microstructure. Lattice relaxation is present within several atomic layers at the interfaces between two adjacent nanodiscs, which introduces about 6 degrees misalignment of these nanocrystals. Analytical electron microscopy analysis reveals that the iron additive atoms distribute uniformly in the nanodiscs and they are substitution atoms of Ni atoms. It has been found that the iron species is critical to the formation and assembly of the hexagonal nanodiscs.     

Sorption of aqueous phosphorus onto bituminous and lignitous coal ashes

Aiming at the development of a phosphorus removal technology for waste water, phosphate (PO(4)(3-)) retention behavior of bituminous and lignitous coal ashes was investigated using a batch reactor. Ash samples, including fresh and weathered fly and bottom ashes, were studied for their sorption isotherms and reversibility. Fly ashes had a much higher phosphate retention capacity (4000-30,000mgP/kg) than bottom ashes (15-600mgP/kg). Lignitous coal ashes were more capable of retaining phosphate than bituminous coal ashes. The retention process was largely irreversible, and the irreversibility increased with the increase in the retention capacity. Weathering enlarged the retention capacity of the bituminous bottom ash, but substantially lowered that of the fly ash, likely due to the difference in the weather-induced changes between the fly and bottom ashes. Sorption isotherms of fly ashes were found to be adequately represented by the Langmuir model while those of bottom ashes fitted better to the Freundlich model. Concentrations of Ca(2+) and PO(4)(3-) in the aqueous phase were measured at the end of sorption and desorption experiments, and were compared with solubilities of three calcium phosphate minerals. The aqueous solutions were saturated or super-saturated with respect to tricalcium phosphate (Ca(3)(PO(4))(2)) and hydroxyapatite (Ca(5)(PO(4))(3)OH), and slightly under-saturated with respect to amorphous calcium phosphate. It is concluded that precipitation of calcium phosphate is the predominant mechanism for phosphate retention by coal ash under the conditions studied. There is a strong and positive correlation between alkalinity and phosphate sorption capacity. Consequently, acid neutralization capacity (ANC) can be used as an indicator of phosphate sorption capacity of coal ashes.     

Fabrication of (Nd(0.01)La(x)Y(0.99-x))2O3 nanoparticles and transparent ceramics by combustion synthesis

Y2O3 acts as the matrix material when doped with different content of La2O3 for reducing sintering temperature and refining grains. The (Nd(0.01)La(x)Y(0.99-x))2O3 nanoparticles and transparent ceramics are fabricated by a combustion synthesis. The powder feature is characterized by TEM. The microstructure, mechanical properties and transmittance of the samples are examined by SEM, HV-1000 hardness tester and fluorescence analyzer respectively. The results show that the (Nd(0.01)La(x)Y(0.99-x))2O3 nanoparticles are homogeneous in size and nearly spherical with average diameter in the range of 40-60 nm. There are no other phases except the Y2O3 cubic phase in the (Nd(0.01)La(x)Y(0.99-x))2O3 nanoparticles. The grains of the samples significantly reduce with increasing La2O3 content. The hardness and fracture toughness increase rapidly first and then gradually tend to plateau with increasing La2O3 content. The transmittance of sample also increases gradually with increasing La2O3, the largest transmittance exceeds 77% when the La2O3 content is x = 0.12.     

Morphology and magnetic properties of diluted magnetic semiconductor 1D nanostructure Ni(x)Sn(1-x)O(2-delta)

SnO2 and Ni(x)Sn(1-x)O(2-delta) (x = 0.007-0.043) 1D nanostructures are fabricated using a catalyzer assisted chemical vapor deposition (CVD). The morphology of the 1D nanostructure is sensitive to the fabrication conditions. As the Ar flux rate is decreased from 50 sccm to 40 sccm, the 1D nanostructure changes from nanowire to nanobelt. All of the Ni(x)Sn(1-x)O(2-delta) 1D nanostructures exhibit room temperature ferromagnetism (RTFM). With the increasing x, magnetic moment per Ni ion increases at first, reaches a maximum of 3.33 microB in x = 0.025, then decreases. The results of annealing in vacuum and oxidizing atmospheres reveal that oxygen vacancies play a crucial role in introducing ferromagnetism, which implies that the origin of RTFM can be understood by the bound magnetic polaron model (BMP).     

Kinetics of decolorization of an azo dye in UV alone and UV/H(2)O(2) processes

The decolorization of C.I. Acid Red 27 (AR27), a monoazo anionic dye, was studied in the ultraviolet radiation (UV) alone and UV plus hydrogen peroxide (UV/H(2)O(2)) processes. The experimental results indicated that the kinetics of both oxidation processes fit well by pseudo-first order kinetics. The reaction rate was sensitive to the operational parameters and increased with increasing H(2)O(2) concentration and light intensity. The reaction orders of H(2)O(2) concentration and light intensity in both processes were obtained with linear regression method. A regression model was developed for pseudo-first order rate constant (k(ap,UV/H(2)O(2))) as a function of the Cconcentration and UV light intensity. (k(ap,UV/H(2)O(2)))=(2 x 10(-4)I(0.75)(0) + k(3)I(1.38)(0)[H(2)O(2)](n)(0))phi(AR27). As a result of two opposing effects of H(2)O(2) concentration at low and high concentrations, n has a value of 0.49 and -0.39 and k(3) has a value of 3 x 10(-4) and 0.1 for the regions of 0 mg l(-1) < [H(2)O(2)](0) < 650 mg l(-1) and 650 mg l(-1) < [H(2)O(2)](0) < 1500 mg l(-1)1, respectively. PhiAR27 is the initial dye concentration correlation index for developing of model for different initial concentrations of AR27. This rate expression can be used for predicting k(ap,UV/H(2)O(2) at different conditions in UV alone and UV/H2O2 processes. The results show that UV alone cannot be an efficient method for decolorization of AR27 in comparison with UV/H(2)O(2) process, therefore the first term of the model can be neglected.     

Ametryn degradation in the ultraviolet (UV) irradiation/hydrogen peroxide (H2O2) treatment

Ultraviolet (UV) irradiation (253.7nm) in the presence of hydrogen peroxide (H(2)O(2)) was used to decompose aqueous ametryn. The concentrations of ametryn were measured with time under various experiment conditions. The investigated factors included H(2)O(2) dosages, initial pH, initial ametryn concentrations, and a variety of inorganic anions. Results showed that ametryn degradation in UV/H(2)O(2) process was a pseudo-first-order reaction. Removal rates of ametryn were greatly affected by H(2)O(2) dosage and initial concentrations of ametryn, but appeared to be slightly influenced by initial pH. Furthermore, we investigated the effects of four anions (SO(4)(2-), Cl(-), HCO(3)(-), and CO(3)(2-)) on ametryn degradation by UV/H(2)O(2). The impact of SO(4)(2-) seemed to be insignificant; however, Cl(-), HCO(3)(-), and CO(3)(2-) considerably slowed down the degradation rate because they could strongly scavenge hydroxyl radicals (OH) produced during the UV/H(2)O(2) process. Finally, a preliminary cost analysis revealed that UV/H(2)O(2) process was more cost-effective than the UV alone in removal of ametryn from water.     

Adsorption behavior of Cu(II) onto titanate nanofibers prepared by alkali treatment

Novel low-cost adsorbents of titanate nanofibers with formula Na(x)H(2-x)Ti(3)O(7) · nH(2)O have been prepared by alkali treatment for Cu(II) removal from aqueous solutions. The nanofibers have structures in which three edge-shared TiO(6) octahedras join at the corners to form stepped, zigzag Ti(3)O(7)(2-) layers. The sodium cations located between the layers are exchangeable. The results of batch adsorption experiments suggest that the nanofibers with high sodium content can be effective adsorbents for Cu(II) removal. Effects of several important factors such as Na amount in adsorbents, pH, temperature, contact time and initial concentration are systematically studied. Results show that the adsorption is highly pH-dependent and the removal is almost complete (99.8%) for initial concentration under 100mg/l at pH 4. Equilibrium adsorption follows Langmuir isotherms well and the maximum Cu(II) uptake calculated is 167.224 mg/g. The adsorption kinetics can be explained by pseudo-second-order model well and the time needed for equilibrium is 180 min. Thermodynamic study indicates that the adsorption is spontaneous and endothermic. Desorption of Cu(II) from adsorbents using EDTA-2Na solutions exhibits a high efficiency and the adsorbents can be used repeatedly. These results demonstrate that the titanate nanofibers are readily prepared, enabling promising applications for the removal of Cu(II) from aqueous solutions.     

涂层成分对IrO_2（5）TiO_2（60）Co_3O_4（x）RuO_2（35

用电化学和Ｘ射线衍射方法研究了氧化物涂层成分对热分解法制备的ＩｒＯ２（５）ＴｉＯ２（６０）Ｃｏ３Ｏ４（ｘ）ＲｕＯ２（３５—ｘ）／Ｔｉ阳极材料析氯速率的影响．ｘ值为０－１３ｍ／ｏ时，氧化物涂层为单相金红石型固溶体，阳极析氯速率随ｘ值增加，ｘ值大于１３ｍ／ｏ时，涂层中出现尖晶石Ｃｏ３Ｏ４第二相，析氯速率随ｘ值下降．     

Temperature dependence of oriented growth of Pb[Yb(1/2)Nb(1/2)]O(3)-PbTiO(3) thin films deposited on LNO/Si substrates

(1-x)Pb[Yb(1/2)Nb(1/2)]O(3)-xPbTiO(3) (PYbN-PT, x=0.5)(001) oriented thin films were deposited onto LaNiO3 (LNO)/Si(001) substrates by sol-gel processing. The crystallographic texture of the films was controlled by the annealing temperature and heating rate. Highly (001) oriented LNO thin films were prepared by a simple metal organic decomposition technique, and the samples were annealed at 700 °C and 750 °C using a rapid thermal annealing process and furnace, respectively. X-ray diffraction analysis revealed that the films of PYbN-PT were highly (001) oriented along LNO/Si substrates. The degree of PYbN-PT orientation is dependent on the heating rate and annealing temperature. Annealing heating rate of 10 °C/s and high annealing temperature near 750 °C produce the greatest degree of (001) orientation, which gives rise to improved dielectric properties.     

Electrochemical and thermal behaviour of Li[Li(x)(Ni0.3Co0.1Mn0.6)1 - x]O2 (x = 0.09, 0.11) cathode Materials for lithium rechargeable batteries

High rate capable Mn-rich layered Li[Li(x)(Ni0.3Co0.1Mn0.6)1-x]O2 (x = 0.09, 0.11) cathode materials that are fully charged are investigated with respect to stability. Differential scanning calorimetry is used to determine the thermal stability of cathode material compositions together with PVdF binder and a conductive agent by heating from 30 degrees C to 400 degrees C at 10 degrees C/min. In the Li[Li(x)(Ni0.3Co0.1Mn0.6)1-x]O2 (x = 0.09, x = 0.11) cathode materials, the exothermic reaction started at 100 degrees C. Due to thermal runway, a sharp peak was observed at 279.25 degrees C for the material of x = 0.09 with exothermic heat generation of 168.4 J/g. For the Mn-rich cathode material, where x = 0.11, two relatively smaller peaks appeared at 250.72 degrees C and 268.60 degrees C with heat evolution of 71.49 J/g and 93.67 J/g, respectively. These layered cathode materials are thermally stable. The x = 0.09 composition shows huge heat flow occurrence when compared to the x = 0.11. It is concluded from a heat generation analysis that the two Mn-rich cathode materials are thermally stable for lithium rechargeable batteries.