Advanced Materials Research Vols. 399-401

Abstract: Nanoscale zero-valent iron (NZVI) particles were supported onto activated carbon fiber (ACF) by impregnating ACF with ferrous sulfate followed by chemical reduction with NaBH₄. A new kind of material ACF/NZVI with approximate 9.64% (wt%) iron was prepared, the structure of the prepared ACF/NZVI was characterized bySEM, XRD and BET. The average NZVI particles with the size of 8.1nm were well dispersed on the ACF. The activity of the prepared ACF/NZVI was evaluated for removing chloroform in water. When 5g/L of ACF/NZVI was added into water with 10 mg/L chloroform, more than 90% of chloroform in water was removed in 48h at pH7.0 and (25±2) ºС. The dechlorination and adsorption of chloroform on ACF/NZVI took place at the same time. The total Chloroform removal by ACF/NZVI was 53.1% after 48h. Consequently, ACF/NZVI exhibits the potential of simultaneous adsorption and dechlorination for chlorinated organic contaminants in water.

Abstract: Fe₂O₃/attapulgite(ATP) catalyst was successfully prepared for Fenton reaction to degrade anion an surfactant, Sodium dodecyl benzene sulfonate(SDBS). Through a number of batch degradation experiments under various conditions, it was found that the reactivity of the system increased by increasing Fe₂O₃/ATP dosage and temperature. The SDBS degradation ratio will increase with increasing H₂O₂ concentration at some extent. But too high H₂O₂ concentration will make degradation efficiency decrease. The system maintains high efficiencies all experimental pH value(2-10).

Abstract: The influence from the dense film coverings generated during the post treatment of TiCl₄ on the photoelectric conversion efficiency of the dye-sensitized solar cells (DSSCs) is investigated in the present paper. The effect of TiCl₄ treatment can be concluded into the following two points: 1. Covering TiO₂ nanoparticles with dense films and protecting the active Ti³⁺ can enhance the electron transport. 2. The dense TiO2 is an ideal conducting film to cover the neck of nanoparticles, reduce the electron scattering and strengthen the electron transport. Acceleration of the electron transport can increase the short circuit current of the DSSCs as to obtain higher photoelectric conversion efficiency.

Abstract: Through the application of parallel and vertical magnetic field, which range from 0T to 1.0T, the effects of electromagnetic field in electrodepositon process to prepare Ni-Mo-P coating on its micro-morphology, alloying component, crystal structure and hydrogen evolution activity were investigated. The results showed that the surface of Ni-Mo-P coating obtained was smooth with less ball cellular depositions under an external vertical magnetic field. The coating showed more ball cellular depositions, and the number of which increased gradually with the increasing of the magnetic field intensity under an external parallel magnetic field. The content of Mo increased slightly and the plating structure has switched from transition state into the amorphous state with applied magnetic field. Ni-Mo-P coating obtained with parallel magnetic field had the highest hydrogen evolution activity, while the hydrogen evolution activity decreased under Vertical magnetic field.

Abstract: A carbon supported Pt-SnO₂/C catalyst was prepared by hydrothermal method .The Pt-SnO₂/C electrode was prepared by electrostatic spinning. Factors of product in solution, different Nafion loading and different loading of Pt-SnO₂/C catalyst were evaluated for their effects on ethanol oxidation reaction (EOR). Electrocatalyst was characterized by SEM,EDS and XRD. At the same time, Electrocatalyst was tested by cyclic voltammetry (CV) , Chronoamperometry, AC impedance at three-electrode under similar conditions to those of the DEFC. The results show that the Nafion loadings was 7.5wt.％, which the loading amount of Pt was 1.5mg•cm^-2, the Pt-SnO₂/C electrode has the highest activity for ethanol oxidation. Compared to the low potential, the oxidation peak current density was 2 times high obtained.

Abstract: Nanocomposites supercapacitors electrodes are synthesized by homogeneously coating the nano-structured polypyrrole (PPy) on multi-walled carbon nanotubes (MWCNTs) via a facile electrochemical method. The capacitance properties of the composites are evaluated by cyclic voltammetry (CV) and galvanostatic charge/discharge techniques. The results show that the porous composites structure exhibit a remarkable specific capacitance of 674 F g^-1 at a current density of 2 A g^-1. Electrochemical experiments indicate that the high specific capacitance is associated with uniform PPy coating. Moreover, the composites present a nearly ideal rectangular shape of cyclic voltammetry characteristics. The stability of the composites electrode is also examined and only 10% capacitance decrease after 800 cycles. This technique provides a feasible solution for developing high-performance electrical energy storage devices.

Abstract: The nanocrystalline and amorphous Mg₂Ni_1-xCo_x (x=0, 0.1, 0.2, 0.3, 0.4) alloys were prepared by melt-spinning technique. The structures of the alloys were studied by XRD, SEM and HRTEM. The hydrogen absorption and desorption kinetics and the high rate discharge ability (HRD) of the alloys were measured. The results show that the as-spun Co-free alloy holds a typical nanocrystalline structure, whereas the as-spun alloys containing Co display a nanocrystalline and amorphous structure, confirming that the substitution of Co for Ni facilitates the glass formation in the Mg2Ni-type alloy. The substitution of Co for Ni evidently improves the hydriding and dehydriding kinetics and the HRD of the alloys. With an increase in the amount of Co substitution from 0 to 0.4, the HRD value rises from 52.9% to 60.3% for the as-cast alloy, and from 65.9% to 76.0% for the as-spun (30 m/s) alloy.

Abstract: In this paper, Bi₂O₃ and Fe³⁺-doped Bi₂O₃ photocatalysts with different molar ratio of Bi /Fe (nBi:nFe =100:1,2,3,4) was prepared by paralled flaw co-precipitation method. The prepared photocatalysts were characterized by Brunauer-Emmet Teller (BET) method, X-ray diffraction( XRD) and UV-Vis diffuse reflectance spectroscopy. The results show that 3% Fe³⁺-Bi₂O₃ prepared has the highest BET surface area, pore volume, the smallest pore size and the particle average size. 3% Fe³⁺-Bi₂O₃ exhibits the best photocatalytic activity. The results of further experiments show that the specific surface area, UV-Vis diffuse reflectance all play an important role in promotion of photocatalytic activity of Bi₂O₃ nanostructure.

Abstract: ZnO; Quantum Dot-sensitized Solar Cell; CdSe; Photoelectrochemical property Abstract: ZnO nanotubes (NTs) were successfully fabricated with a hydrothermal method at low temperature. X-ray diffraction (XRD) and scanning electron microscopy (SEM) have been utilized to characterize the samples. The ZnO nanotubes, sensitized by CdSe, were used as a photoanode of a quantum dot sensitized solar cell, which generated a maximum power conversion efficiency of 0.95%.

Abstract: Some hydrogen atoms were being charged into metal palladium lattice and reached a certain ratio in a H-Pd gas-loading system under the pressure of P_H2<1atm. The relationship between loading ratio, pressure and excess heat were studied at different reaction conditions. In one of the experiments the palladium wire was broken with a huge excess heat. The calculation results showed that about 2.2×10⁴ Joules excess energy were released in that abnormal process, which was corresponding to 2.5×10²eV for each palladium atom. Analysis on the surface of the melted broken section of palladium wire sample before and after the abnormal process with a scanning electron microscopy (SEM) and an energy dispersive spectrometer (EDS) revealed that new surface topographical features with concentrations of unexpected elements (Ag and Ca) were detected, which implied that the excess heat might come from a nuclear transmutation reaction