Advanced Materials Research Vols. 953-954

Abstract: A novel disk photo-bioreactor was employed to produce hydrogen continuously by Rhodopseudomonas faecalis RLD-53. The ability of hydrogen production was investigated in different feeding times and HRTs. The maximum total hydrogen yield in the photo-bioreactor reached 2.68 mol H₂/mol acetate at 48h HRT and 4d feeding time. Experimental results indicated that feeding times and HRTs are two key factors determined biomass in the photo-bioreactor and hydrogen production capacity. Moreover, the photo-fermentation hydrogen production is strongly dependent on light energy supply, the light conversion efficiency of the novel photo-bioreactor was 1.6%, it is higher than that that of most of reported photobioreactors. Therefore, these results demonstrated that the disk photo-bioreactor was a useful and efficient reactor in entire continuous hydrogen production.

Abstract: On the help of the atmosphere plasma spraying (APS) and suspension plasma spraying (SPS) conditions optimized previously, APS and SPS were both introduced to prepare the PEN (Positive- Electrolyte-Negative) of planar solid oxide fuel cells (SOFCs). Then the microstructure and material components of the PEN cells were analyzed. Experimental results show that the electrolyte layer fabricated by SPS represents higher densification, thinner thickness and more homogeneous component distribution than that manufactured by APS, and meets the microstructure and density requirements of SOFC. The porosities of cathode and anode layers by APS and SPS reached 25%-35%. Therefore, the SPS could be a better and suitable approach to fabricate PENs of SOFC stacks, and effectively improve the conductivity of electrodes.

Abstract: The catalytic hydrogenation kinetics of N-ethylcarbazole over 5 wt% Ru/Al₂O₃ was investigated at various temperatures. The results shows that the hydrogenation reaction was exothermic and high temperature is unfavorable for the reaction rate. Fully hydrogenation was achieved within 1 hour under the best reaction temperature of 170 °C. The kinetics of N-ethylcarbazole follows the first-order kinetics in terms of the reactant concentration but independent of hydrogen pressure, which was maintained as a constant in the reaction process. The apparent activation energy of N-ethylcarbazole hydrogenation reaction at 150-180 °C was found to be 71.2 kJ/mol.

Abstract: Two kinds of proton exchange membranes (PEMs) containing POSS are designed and prepared, one is sulfonated poly (ether ether ketone) (SPEEK)/bisphenol S diglycidyl ether (DEBS)/POSS hybrids with the semi-interpenetrating polymer networks (IPNs) structure and the other is sulfonated polyimides (SPI)/POSS hybrids with cross-link structure. IPNs should be more contributed to improve the proton conductivities of PEMs than cross-link structure.

Abstract: ZnSe cluster is the main form of growth mechanism in CuInGaSe based solar cells as the buffer layer and the building blocks for larger bulk ZnSe materials as well. With the generalized gradient approximation in first principle all-electron calculations, a number of configurations and structural isomers of Zn_nSe_n (n=1~13) nanoclusters has been geometrically optimized to get the lowest energy constructions of Zn_nSe_n (n=1~13). Second-order energy difference were applied to investigate the stability of small ZnSe nanoclusters. And the nanocage Zn₁₂Se₁₂ cluster has been identified to be in rather stable state and can be the building block of larger ZnSe nanoclusters materials. Energy gap between lowest unoccupied molecular orbital and the highest occupied molecular orbital, Infrared Spectroscopy have also been investigated for further study on size and optical properties through testing methods.

Abstract: Plasmonic Au decorated TiO₂ nanosheet film was firstly prepared by the combination of a hydrothermal method and a microwave-assisted chemical reduction process. The prepared sample was characterized by scanning electron microscopy (SEM), UV-vis absorption spectrum (UV-vis) and photoluminescence spectrum (PL) respectively. Results show that Au nanoparticles with narrow distribution are uniformly loaded on the nanosheet surface, and the resulted composite nanostructure exhibits distinct surface plasmon absorption and quenched photoluminescence compared to pure TiO₂ nanostructure. Photocatalytic tests show that Au decorated TiO₂ exhibits enhanced photocatalytic activity for photocatalytic reduction of CO₂ to methanol.

Abstract: Nano-ZnO with high photocatalytic performance was prepared by paralled flaw precipitation method under ultrasonic radiation with Zn(NO₃)₂·6H₂O and NH₃·H₂O as raw materials. The prepared samples were characterized by XRD, SEM and TG/DTA. The decolorization of methylene blue solution as model reaction, the effect of calcining temperature on the structure and photocatalytic performance of the samples were investigated. The results show that nano-ZnO with well crystal property and uniform size distribution, prepared by calcining the precursor at 300 °C for 2 h, had the average diameter of about 38 nm. When 100 mL methylene blue solution with 10 mg/L of mass concentration is treated with the nano-ZnO photocatalyst for 60 min, the decolorizing efficiency of the methylene blue solution reached 62.5 %.

Abstract: Abstract. The large-pore mesoporous Bi-B-TiO2 nanoparticles with the different Bi/Ti rations were prepared by EISA(evaporation-induced self-assembly) method. The prepared catalysts were characterized by X-ray diffraction, transmission electron microscopy, N2 absorption-desorption, ultraviolet visible light spectroscopy and photoluminescence spectroscopy technologies. The results revealed that all the samples are large aperture mesoporous structures. The crystallite sizes were in the range7-11nm, as confirmed by the results obtained from TEM images. The photodecomposition experiments showed that the photodegradation activity of Bi-B-doped TiO2 was higher than that of undoped TiO2 in degradation of 2, 4–dichlorophenol under visible light irradiation.

Abstract: This paper aims to investigate the mass and characteristics of colloid in leaching process to provide useful information for assessing the effects of colloid on leach at vertical and safety assessment of the disposal of (ultra-) low uraniferous radioactive waste. The variation of pH, colloid mass and effects on leach were studied at ambient conditions. The experimental results showed that the formation of colloid was strongly influenced by the pH value, it increased with time from 24 h to 96 h, and mass of colloid showed the opposite trend. The mass of colloid increased by the thick of uranium residual ores from 0.2 m to 0.8 m, but the pH showed opposite trend. The colloid morphology was identified using S-4800 scanning electron microscopy (SEM/EDS), and confirmed Al, Fe, Mg, Cs, U, Pr, O, and C as main composition. It implies that the existence of colloids would retard uranium leaching process. The residue grade of different thick nicely verified this point.

Abstract: Two different types of carbon-based composites are made, to measure their electromagnetic parameters through experiments, which are applied to the construction of high impedance surface electromagnetic band gap absorbing structure. Then, through the application of electromagnetic simulation software HFSSv.11 the reflection coefficients of the models are measured as the electromagnetic frequency changes. The research shows that the application of carbon-based composites can improve the EBG absorbing structure, thus having such functions as heat resistance, corrosion resistance, light weight and high tensile strength. Therefore, it is feasible to apply the carbon-based composite to the EBG absorbing structure to improve its performance.