ISSN 0253-2778

CN 34-1054/N

2014 Vol. 44, No. 8

Display Method:
Rhodanine-containing fullerene derivative as a new acceptor in polymer solar cells with enhanced light absorption
XIE Lixin, ZHAO Xuemei, ZHAO Zhiqiang, ZHEN Jieming, CHEN Muqing, ZHU Jun, DAI Songyuan, YANG Shangfeng
2014, 44(8): 623-636. doi: 10.3969/j.issn.0253-2778.2014.08.001
A dye unit, 3-ethyl rhodanine, was attached onto (6,6)-phenyl-C61 butyric acid methyl ester (PCBM) for the first time, affording a new fullerene acceptor PCBM-rhodanine (PCBRh) for polymer solar cells (PSCs) with enhanced light absorption. The successful attachment of the rhodanine moiety was confirmed by H NMR, 3C NMR and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectroscopies. UV-vis spectroscopic study indicated that PCBRh had stronger absorptions in the region of 300~600 nm than PCBM, and this was due to the high absorption coefficient of the dye unit of 3-ethyl rhodanine. Cyclic voltammetric measurement revealed that the lowest unoccupied molecular orbital (LUMO) level of PCBRh was 0.1 eV higher than that of PCBM, which can be understood by considering the electron donating property of the rhodanine moiety. Using PCBRh as an acceptor blending with poly(3-hexylthiophene-2,5-diyl) (P3HT), the bulk heterojunction (BHJ) PSC device exhibited a power conversion efficiency (PCE) of 146% under the optimized condition (blending ratio of P3HT:PCBM=1:1 (mass ratio), annealing treatment at 135 ℃ for 10 min). The effect of annealing on the morphology of P3HT:PCBRh active layer and its correlation with the device performance were studied by atomic force microscopy (AFM), revealing that in the annealed P3HT:PCBRh blend film P3HT aggregated to long stripes with an average length of ca. 20 nm and the RMS roughness increased compared to that for the reference P3HT:PCBM blend film, thus leading to unfavorable exciton diffusion and dissociation.
Catalytic adsorptive stripping determination of trace chromium based on the bismuth/MWCNTs modified electrode
ZHAO Qiping, WU Shouguo, ZHANG Zhixin, ZHOU Lei
2014, 44(8): 637-647. doi: 10.3969/j.issn.0253-2778.2014.08.002
A sensitive Bi/MWCNTs (multi-walled carbon nanotubes) composite film modified electrode was fabricated by two-step electrodeposition. First, the MWCNTs were electrodeposited instead of dropping coated on the glass carbon electrode(GCE), and the bismuth film was then deposited on the MWCNTs/GCE. A protocol used for the determination of total chromium and hexavalent chromium in water by square wave cathodic adsorptive voltammetry in the presence of cupferron (N-nitroso-N-phenylhydroxylamine ammonium salt) was proposed. In the presence of cupferron, Cr(Ⅲ) can form the complex with cupferron and be accumulated on the surface of the modified electrode by adsorption at a potential of -035 V, and then is reduced with the cathodic scan from -035 V to -110 V. An accumulation time of 2 min results in a detection limit of 005 μg/L Cr(Ⅵ) and a relative standard deviation of 52% (n=75) for 10 μg/L. Application to river water samples is demonstrated. The total chromium can be directly determined by standard addition of Cr(Ⅲ) or Cr(Ⅵ); the Cr(Ⅵ) can be separated with Cr(Ⅲ) by using an anion trapping column and then determined by standard addition of Cr(Ⅵ). The results are consistent with those detected by ICP-MS (inductive coupled plasma mass spectrometry). The attractive behavior of the new “mercury-free” chromium sensor holds great promise for on-site environmental and industrial monitoring of chromium.
Synergistic toxicity of bulk zinc oxide and cadmium chloride in mice
GAO Shang, XU Xiaolong, WANG Shasha, ZHU Shanshan, RONG Rui, LI Bing
2014, 44(8): 648-654. doi: 10.3969/j.issn.0253-2778.2014.08.003
The wide applications of zinc oxide (ZnO) and ubiquitous cadmium (Cd) pollution have increased the risk of humans co-exposure to ZnO and Cd. The synergistic toxicity of bulk ZnO and CdCl2 in mice was investigated. Mice were randomly divided into four groups: a control group and three experimental groups (bulk ZnO, CdCl2, bulk ZnO+CdCl2). Bulk ZnO shows low toxicity in mice. In contrast, CdCl2 causes siginificant damage in the liver indicated by severe liver dysfunction and histopathological abnormalities. Although co-exposure to bulk ZnO and CdCl2 has positive synergistic effects on the uptakes of Zn and Cd in the liver, bulk ZnO can significantly alleviate CdCl2-induced damage in the liver. The bulk ZnO-induced metallothionein synthesis and the inhibition of Cd-induced deprivation of tissue Zn by bulk ZnO might play two key roles in the protective effect of bulk ZnO on CdCl2-induced damage in the liver.
Application of Anaerobic Digestion Model No.1 combining hydrodynamics in UASB reactor
HE Jia, HUO Yinchao, ZHANG Ze, MU Yang, Raymond J Zeng
2014, 44(8): 655-660. doi: 10.3969/j.issn.0253-2778.2014.08.004
A novel Anaerobic Digestion Model No.1 based dispersive model was developed to simulate the upflow anaerobic sludge blanket reactor (UASB), in which both hydrodynamics and bio-dynamics were taken into account. The partial differential equations in the model was solved by finite difference method in Matlab. A tracer study and two loading-shock experiments were used to validate the reactors hydrodynamics and bio-dynamics, respectively. The simulated data match the experimental data very well. Besides, the developed model can reflect the reactors status at different heights, which makes it possible to give early warnings in abnormal situations.
Photocatalytic activity of ZnO/graphene core-shell structure and its mechanism study
YANG Xiaoyu, WANG Chao, HONG Dexiong, FANG Mingliang, CAI Liang, CHEN Ling, YAN Wensheng
2014, 44(8): 661-666. doi: 10.3969/j.issn.0253-2778.2014.08.005
The ZnO@RGO quasi-core-shell composite photocatalyst, where ZnO nanoparticles (NPs) were wrapped by graphene nanoshells, was prepared via a one-step method. Photocatalytic experiments indicated that the photodegradation efficiency of ZnO@RGO on methylene blue (MB) increased by about 10 times compared to that of ZnO NPs. ZnO nanocrystals with the particle size of about 6 nm wrapped by RGO (reduced graphene oxide) nanosheets could be observed in transmission electron microscopy (TEM) images. X-ray diffraction (XRD) patterns showed that the structure of ZnO was hexagonal wurtzite. X-ray photoelectron spectroscopy (XPS) and Raman scattering manifested that there was strong interfacial interaction between ZnO and graphene which introduced about 3% interfacial stress and quantities of oxygen vacancies(VO). Photoluminescence (PL) further evidenced the approximately 80% decrease in band-gap emission intensity in ZnO@RGO compared with that in ZnO and the presence of interfacial VO. Finally, the mechanism of the enhanced photocatalytic activity in ZnO@RGO was proposed. The effective synergetic capture of graphene nanoshells and VO as a result of interfacial strain interaction improves the photocatalytic activities of ZnO based semiconductor photocatalysts.
Magnetic properties of Ni1-xMnxO diluted magnetic semiconductor
WANG Chao, HONG Dexiong, YANG Xiaoyu, FANG Mingliang, CAI Liang, CHEN Ling, YAN Wensheng
2014, 44(8): 667-671. doi: 10.3969/j.issn.0253-2778.2014.08.006
The microstructural and magnetic properties of Ni1-xMnxO (001≤x≤005) thin films prepared by pulsed laser deposition (PLD) were studied by combining X-ray absorption near edge structure (XANES) spectroscopy, superconducting quantum interference device (SQUID) and first-principles calculations. XANES results at Mn K-edge show that at the low Mn doping level of x≤003, the Mn ions in the mixed oxidation valence state (+2/+3) are incorporated substitutionally into the NiO host, while at higher doping level of x>003 Mn2O3-like impurity phase is formed. Magnetization measurements indicate that the saturation magnetic moment of Ni1-xMnxO film increases from 03 to 045 μB/Mn as the Mn content rises from 001 to 003. It is proposed that interactions between Mn3+ ions mediated by Ni vacancies exhibit ferromagnetic coupling, while interactions between Mn2+ ions exhibit antiferromagnetic coupling through superexchange interaction.
Study on the structure and supercapacitive properties of Mesoporous Co3O4 nanosheets
FANG Mingliang, BAO Jie, WANG Chao, YANG Xiaoyu, HONG Dexiong, CAI Liang, CHEN Lin, SUN Zhihu
2014, 44(8): 672-678. doi: 10.3969/j.issn.0253-2778.2014.08.007
Measurements of XRD (X-ray diffraction), TEM (transmission electron microscopy) and N2 adsorption-desorption isotherms were combined to study the phase and microstructure of mesoporous Co3O4 nanosheets synthesized at different temperatures. The mechanism of calcination temperature influencing the supercapacitive performance of the Co3O4 nanosheets was also investigated. It is indicated from the XRD and TEM results that the as-prepared Co3O4 nanosheets are in a pure spinel phase and in a mesoporous morphology, and the crystallinity increases with the calcination temperature. The N2 adsorption-desorption isotherms measurement shows a decrease of the specific surface area from 279 to 22 m2/g as the calcination temperature increases from 300 to 500 ℃. Electrochemical characterization reveals the best supercapacitor performance of the nanosheets obtained at 400 ℃, with a capacity of 151 F/g that is twice the values of the products calcined at 300 and 500 ℃. Based on these results, it was proposed that the synergistic effects of the crystallinity and the surface microstructure of the mesoporous microstructures are key factors for the supercapacitive performance of the Co3O4 nanosheets. Compared with the nanosheets calcined at 300 ℃, the 400 ℃ sample possesses better crystallinity, which is beneficial to the electron transfer during the redox reaction of the electrodes. In comparison with the nanosheets calcined at 500 ℃, the 400 ℃ calcined sheets have the proper BET specific surface area, facilitating the participation of electrolyte in the electrode reaction.
Observation study on concentration diurnal variation of atmospheric pollutants in Tongling City
ZHANG Hong, LIU Guijian, MEI Jianming, LIU Huijuan, XUE Huaqin
2014, 44(8): 679-688. doi: 10.3969/j.issn.0253-2778.2014.08.008
Using the monitoring data of atmospheric pollution and meteorological data from 2007 to 2010, the concentration diurnal variations of atmospheric pollutants (including SO2, NO2 and PM10) in Tongling City were analyzed, and the relationship between the diurnal variations of atmospheric pollutants and meteorological factors was studied. The results show that the diurnal variations of atmospheric pollutant concentrations and meteorological factors can be classified into two types, “single pink and single valley type” and “double pinks and double valleys type”. There is no spatial variation in SO2 and PM10, while NO2 exhibited obvious spatial variation. For areas near the pollution source, pollutant concentration is correlated with atmospheric pressure, relative humidity and temperature, but not with wind speed. For the observation points free from pollutants, the relationship of pollution concentration variation and meteorological factors is similar to the area near the pollution source, and the pollution concentration variation is reversely correlated with wind speed. The other observation points of Tongling City, which are not included in the two, showed little relationship between pollutant concentration variation and meteorological factors.
Effect of Chaohu Lake sediment on inorganic nitrogen components of copper tailings and growing development of three leguminous species
WANG Yupeng, SHEN Zhangjun, ZHANG Zhen
2014, 44(8): 689-696. doi: 10.3969/j.issn.0253-2778.2014.08.009
To study the effect of Chaohu Lake sediment on inorganic nitrogen components of copper tailings and the growing development of leguminous plants, three leguminous plants Crotalaria juncea, Amorpha fruticosa, and Robinia pseudoacacia were potted in copper mine tailings sand as matrix with rotten airing Chaohu Lake sediment according to different mixing proportions. The results showed that the values of chlorophyll a, chlorophyll b and chlorophyll a+b of the leaves in C. juncea and R. pseudoacacia were the biggest. The ratios of chlorophyll a/b of the three leguminous plants were between 089 and 118. With the raising of Chaohu Lake sediment contents in the matrix, the ratios of chlorophyll a/b of plants increased. In the same treatment, the values of chlorophyll a and chlorophyll b, chlorophyll a+b in C. juncea were significantly higher than those of A. fruticosa and R. pseudoacacia (P<005). The activities of SOD and POD in the three kinds of plant leaves increased with the increase in the proportion of Chaohu Lake sediment. Nitrate nitrogen was the main form of availability nitrogen in the treatment matrix with the 3 kinds of leguminous plants growing, whose content reached 855%~9384% of the total inorganic nitrogen content. After adding the Chaohu Lake sediment, ammonium nitrogen and nitrate nitrogen contents in the matrix were both raised: 100~134 times and 134~157 times the value of the control in A. fruticosa matrix, 133~324 times and 074 ~ 110 times the value of the control in C. juncea matrix, and 085~116 times and 085~109 times of the control in R. pseudoacacia matrix. Comprehensive analysis shows that Chaohu Lake sediment can effectively improve the nutrition conditions of copper tailings matrix and promote plant growth. Under the improved nutrition condition, all three plants can be used as ecological restoration plants in tailings, among which C. juncea is the best.
Simulation research on leakage and dispersion of multi-source heavy gas
ZHU Hongya, CHEN Haodong, WANG Qingsong, SUN Jinhua
2014, 44(8): 697-703. doi: 10.3969/j.issn.0253-2778.2014.08.010
The risk from the leakage and dispersion of heavy gas is much more serious than that of light gas due to the existence of heavy gas effect. A multi-source dispersion model of heavy gas was developed on the basis of a single SLAB model. And the dispersion behaviors of single and multi-source heavy gas at the mode of continuous and instantaneous leakage were simulated. Then, with a case study of chlorine, the downwind time-averaged concentration distribution under corresponding conditions was calculated. Further, combined with the toxicity criteria, the accident-affected areas at different toxic levels were presented to provide theoretical guidance for emergency rescue and evacuation decision-making.
Experimental study and hazard analysis on flammable liquids in an altitude chamber
DING Chao, ZHOU Dechuang, YAO Jiajie, WANG Jian
2014, 44(8): 704-708. doi: 10.3969/j.issn.0253-2778.2014.08.011
Flash point, one of the main indicators to evaluate the fire hazard, is an important physical property of the flammable liquids. Using a portable flash point measuring apparatus, a series of measurements of two mono compound fuels (n-decane and n-hexanol) and two mixture compound fuels (0# diesel and Jet A) at different pressures were carried out in an altitude chamber at 35, 45, 55, 65, 75, 85, 45 and 101 kPa. The experiment results show that the flash point is in a non-linear relationship with the pressure. And using the theoretical analyses from previous studies, it can be verified that analog low pressure is in good agreement with the real situation. Based on the classification codes in China, the fire hazard class of the flammable liquids at different pressures has been given. The results can provide a scientific basis for the production, storage, transport and use of fuel in the plateau environment, as well as fire safety in aviation.