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1.
Using solar energy to produce syngas via the endothermic reforming of methane has been extensively investigated at the laboratory- and pilot plant-scales as a promising method of storing solar energy. One of the challenges to scaling up this process in a tubular reformer is to improve the reactor's performance, which is limited by mass and heat transfer issues. High thermal conductivity Cu foam was therefore used as a substrate to improve the catalyst's thermal conductivity during solar reforming. We also developed a method to coat the foam with the catalytically active component NiMg_3AlO_x. The Cu foam-based NiMg_3AlO_x performs better than catalysts supported on SiSiC foam, which is currently used as a substrate for solar-reforming catalysts, at high gas hourly space velocity(≥400,000 mL/(g·h)) or at low reaction temperatures(≤ 720 °C). The presence of a γ-Al_2O_3 intermediate layer improves the adhesion between the catalyst and substrate as well as the catalytic activity.  相似文献   

2.
Zhang  Shicong  Ye  Haonan  Ding  Haoran  Yu  Fengtao  Hua  Jianli 《中国科学:化学(英文版)》2020,63(2):228-236
Dye-sensitized photoelectrochemical tandem cells have shown the promise for light driven hydrogen production from water owing to the low cost,wide absorption spectra in the visible region and ease to process of their constitutive photoelectrode materials.However,most photo-driven water splitting photoelectrochemical cells driven by organic dye sensitized solar cells exhibit unsatisfactory hydrogen evolution rate,primarily attributed to their poor light capturing ability and low photocurrent performance.Here we present the construction of a tandem system consisting of an organic blue-colored S5 sensitizer-based dyesensitized photoelectrochemical cell(DSPEC) wired in series with three spectral-complemental dyes BTA-2,APP-3 and APP-1 sensitizers-based dye-sensitized solar cell(DSC),respectively.The two spectral-complemental chromophores were used in DSC and DSPEC to ensure that the full solar spectrum could be absorbed as much as possible.The results showed that the photocurrent of tandem device was closely related to the open-circuit voltage(Voc) of sensitized DSC,in which the tandem configuration consisting of S5 based DSPEC and BTA-2 based DSC gave the best photocurrent.On this basis,tandem device with the only light energy and no external applied electrical bias was further constructed of BTA-2 based 2-junction DSC and S5 based DSPEC and obtained a photocurrent of 500 μA cm-2 for hydrogen generation.Furthermore,I-/I3-was used as a redox couple between dye regeneration and O2 production on the surface of Pt-IrO2/WO3.The strategy opens up the application of pure organic dyes in DSC/DSPEC tandem device.  相似文献   

3.
A novel benzodithiophene-containing organic dye BDT was synthesized and characterized as a sensitizer for a nanocrystalline TiO2-based dye-sensitized solar cell.The BDT dye shows two major electronic absorptions.The absorption of the BDT dye covers a broad visible range from 300 nm to 550 nm.The benzodithiophene unit was used as aπbridge with several advantages:(1) It facilitates the electron transfer from the donor to the acceptor;(2) A facile structural modification on the 4,8-positions in the benzodithiophene unit can be achieved;(3) Fusing benzene with two flanking thiophene units improves the thermal stability.Under simulated AM1.5G solar light(100 mW/cm2) illumination,the DSC based on BDT gives a power conversion efficiency of 1.78%.  相似文献   

4.
Here we reported the fabrication of efficient polymer solar cells from regioregular poly(3-hexylthiophene) (P3HT):fullerene derivative [6,6]-phenyl-C61 butyric acid methyl ester (PC6jBM) mixtures, in which solution- processed vanadium oxide (VOx) was used as a hole-extracting layer (HEL). The obtained devices exhibited a high power conversion efficiency of 3.96%, and can be enhanced to 4.06% and 4.16%, respectively, when two types of PEDOT:PSS with different conductivities were used in conjunction with the VOx layer. All the VOx-based devices showed a high fill factor (FF) over 70%, which was ascribed to efficient hole extracting efficiency associated with the solution-processed VOx hole-extracting layer. The origins of the improvement were also studied by transmission spectra, atomic force microscope (AFM), and capacitance-voltage characteristics.  相似文献   

5.
This paper reports the synthesis and characteristics of a series of alkyl-substituted planar polymers. The physical properties are carefully tuned to optimize their photovoltaic performance. Depending on the length of soluble alkyl side chains which modify the structural order and orientation substantially in polymer backbones, the device performance can be improved significantly. The tuning of HOMO energy levels optimized polymers’ spectral coverage of absorption and their hole mobility, as well as miscibility with fullerene; all these efforts enhanced polymer solar cell performances. The shortcircuit current, Jsc for polymer solar cells was increased by adjusting polymer chain packing ability. It was found that films with well distributed polymer/fullerene interpenetrating network exhibit improved solar cell conversion efficiency. Enhanced efficiency up to 5.8% has been demonstrated. The results provide important insights about the roles of flexile chains in structure-property relationship for the design of new polymers to be used in high efficient solar cells.  相似文献   

6.
Producing chemical fuels from sunlight enables a sustainable way for energy consumption.Among various solar fuel generation approaches,photocatalytic CO2 reduction has the advantages of simple structure,mild reaction condition,directly reducing carbon emissions,etc.However,most of the current photocatalytic systems can only absorb the UV-visible spectrum of solar light.Therefore,finding a way to utilize infrared light in the photocatalytic system has attracted more and more attention.Here,a Z-scheme In2S3-TiO2 was constructed for CO2 reduction under concentrated natural sunlight.The infrared light was used to create a high-temperature environment for photocatalytic reactions.The evolution rates of H2,CO,and C2H5OH reached 262.2,73.9,and 27.56μmol?h-1?g-1,respectively,with an overall solar to fuels efficiency of 0.002%.This work provides a composite photocatalyst towards the utilization of full solar light spectrum,and could promote the research on photocatalytic CO2 reduction.  相似文献   

7.
Ethidium bromide is a fluorescent tag and is used in biomedical applications.It is a potent mutagen because of its DNA intercalating nature.A catalyst composition for the feasible elimination of ethidium bromide using a broad spectrum of solar radiation was investigated.Nanostructured anatase TiO2 was synthesized by gel to crystalline conversion and its bandgap was engineered by doping with zirconium to effectively harness sunlight.The doped nanocrystals were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,energy dispersive X-ray analysis,and UV-Vis spectroscopy.The formed crystals retained the anatase phase with a marginal increase in size.The pulverization process used to dope Zr into titania resulted in a nano and doped lattice with an increased and extended light absorption range,which gave a nearly five-fold increase in photoactivity over pure titania.The catalytic effect of the modified titania,the dopant concentration,and the dynamics of the dopant concentration on the charge carriers(trapping-recombination)for the degradation of the mutagen was investigated.The modified titania is capable of total ethidium bromide elimination in sunlight.The loss of its mutagenic property was confirmed by an Ames test.The induced revertant colonies observed were nil in the treated sample indicating a complete loss of the intercalating property of the mutagen.  相似文献   

8.
How to utilize inexhaustible solar light as a means of disinfection technology for its cheap and green remains a challenge. In this work, core-shell ZnO@ZIF-8 was synthesized and used for bacterial inactivation synergizing with peroxymonosulfate(PMS) under visible light irradiation. It took 50 min to achieve thorough sterilization for 7.5-log Escherichia coli(E. coli) cells in vis/PMS/ZnO@ZIF-8 system, compared with that 4.5-log reduction completed in vis/PMS/Zn O system under the same condition...  相似文献   

9.
Two novel fluorene-based hole transporting materials(HTMs) were synthesized to be used in perovskite solar cells(PSCs). C102 was designed based on C101 by simply linking the two carbon–carbon single bonds to compose a "dispiro" structure. Their typically similar structures cause them sharing almost the same energy levels. However, their photovoltaic performances are quite different due to the small variations. The PSC that contained the "dispiro" structure, C102, reached a power conversion efficiency(PCE)of 17.4%, while the device contained C101, obtained a lower PCE of 15.5%. Electrochemical properties and Photovoltaic characterization of the two materials have been investigated to explain the result. It is shown that C102 has a stronger ability to transport holes and resist the charge recombination. Thus, the dispiro structure should be more appropriate being used as HTM in PSCs.  相似文献   

10.
顶空气相色谱法测定香水中的甲醇   总被引:20,自引:0,他引:20  
张强 《色谱》1995,13(2):144-144
In this paper. headspace GC was used to determine methanol in perfume. Separation was performed on a GDX-201 column. 2m×3mm i.d. at 150℃. The characteristics of this method are sensitive. accurate and with less interference. This new method can be used for determination of methanol in cosmetics.  相似文献   

11.
A new method for the analysis of copper and its speciation in Rhizoma coptidis was proposed using chelatometric dispersive liquid-liquid microextraction(cDLLME) followed by capillary electrophoresis. Dithizone was used as a chelating agent for extraction and carbon tetrachloride and ethanol were used as extraction and dispersive solvent,respectively.The calibration curve was linear in the range of 0.5- 20.0μg/mL with a correlation coefficient of 0.9990(n = 6) and the average recovery was in the range of 88.26%-94.44%.The method was successfully used to determine the total and water soluble copper in Rhizoma coptidis herbal medicine.The results suggested that it would be reasonable to setting the criterion of heavy metals in an herbal medicine according to the dosage forms.  相似文献   

12.
Metal-free g-C_3N_4 is widely used in photocatalytic reactions owing to its suitable band structure.However, it has low specific surface area and insufficient absorbance for visible light, and its photoexcited carriers have high recombination rates. In this study, the 3 D macropore C-vacancy g-C_3N_4 was prepared through a facile one-step route. Polymethylmethacrylate is used as a template to increase the surface reaction sites of g-C_3N_4 and extend its visible-light range. Compared to unmodified g-C_3N_4, the H2 production and CO_2 reduction rates of the fabricated g-C_3N_4 significantly improved. The special pore structure significantly improved the light utilization efficiency of g-C_3N_4 and increased the number of surface-active sites. The introduction of C-vacancy extended the absorption band of visible-light and suppressed the carrier recombination. The newly developed synthesis strategy can improve solar energy conversion efficiency and potentially modifies g-C_3N_4.  相似文献   

13.
Two-dimensional(2 D)covalent organic frameworks(COFs)with periodic functionalπ-electron systems are an emerging class of optoelectronic materials.However,almost all conjugated COFs so far are insoluble and hard to process,which hampers severely their optoelectronic applications.Here,a solution-processable,nanoscale and sp2 carbon-conjugated COF-like material,PDPP-C20 was successfully designed and synthesized.The solution-processed PDPP-C20 films exhibit high crystallinity and excellent charge transport properties along out-of-plane directions,combined with the highest occupied molecular orbital(HOMO)/lowest unoccupied molecular orbital(LUMO)levels of-5.36/-3.75 e V,making PDPP-C20 suitable for electronic device applications.An efficiency as high as 21.92%has been demonstrated when it was used as a functional interfacial layer in perovskite solar cells,coupled with dramatically improved stability in comparison with the control device due to the superior hydrophobicity of PDPP-C20 layer as well as its passivation effect on perovskite surface.Furthermore,the soluble PDPP-C20 could also be used as donor in bulk-heterojunction organic solar cells and an initial efficiency of 2.46%has been achieved.These results indicate that this new class of soluble and nanoscale COF-like materials should offer a new arena of functional materials for optoelectronic devices.  相似文献   

14.
A chromatographic method and a dynamic Wicke-Kallenbach method (DMWK) were used to determine the diffusion characteristics of two industrial copper containing catalysts. The first catalyst was used in nitrobenzene hydrogenation to aniline and the second was used in a low temperature water-gas shift reaction. Experimental results show that application of these two methods leads to similar results. Experimental data obtained allow for monitoring changes in the texture of the catalyst grains and intraparticle diffusivity of gaseous reagents at different states of the catalyst activity and use, which can be used as criteria for designing optimal industrial catalyst pellets.  相似文献   

15.
In this work,ternary organic solar cells(OSCs)combining a fullerene derivative PC71BM with a nonfullerene acceptor N2200-F blended with a polymer donor PM6 were reported.Compared with the binary systems,the highest power conversion efficiency(PCE)of 8.11%was achieved in ternary solar cells with 30 wt%N2200-F content,mainly due to the improved short-circuit current density(Jsc)and fill factor(FF).Further studies showed that the improved Jsc could attribute to the complementary abso rption of the two acceptors and the enhanced FF was originated from the higher hole mobility and the fine-tuned morphology in the ternary system.These results demonstrate that the combination of fullere ne and nonfullerene acceptors in ternary organic solar cells is a promising approach to achieve high-performance OSCs.  相似文献   

16.
Polyurea microcapsules about 2.5μm in diameter containing phase change material for thermal energy storage application were synthesized and characterized by interfacial polycondensation method with toluene-2,4-diisocyanate and ethylenediamine as monomers in an emulsion system. Hexadecane was used as a phase change material and OP, which is nonionic surfactant, and used as an emulsifier. The chemical structure and thermal behavior of the microcapsules were investigated by FTIR and thermal analysis respectively. The results show encapsulated hexadecane has a good potential as a solar energy storage material.  相似文献   

17.
Combinatorial approach was first used to synthesize and optimize luminescent Gd2O3:Tb nanocrystals. Orthogonal Design was used to investigate their properties comprehensively. The megascopic photoluminescence properties have been observed under ultraviolet light by a 254 nm laser. The structural properties of Gd2O3:Tb were further studied and optimized by X-ray diffraction and transmission electron microscopy. The visible luminescence spectra were investigated under excitation by a 284 nm laser. Glutin reaction process was discussed as the possible mechanisms. Finally, the optimized sample was obtained with the best properties in some scope.  相似文献   

18.
Pentamethylcyclopentadienyl-trimethylphosphine-metal compounds play an important role in the activation studies of saturated hydrocarbons. A method to synthesize ethyltetramethylruthenium compounds was established, which started from the reaction of RuCl_3. H_2O with ethyltetramethylcyclopentadiene to give a dimer compound of 2. When 2 was reacted with different amounts of trimethylphosphine, compounds 3 [C_5Me_4EtRu(PMe_3)Cl_2] and 4 [(C_5Me_4Et)Ru(PMe_3)_2Cl] were obtained. Compound 3 is a 17-electron species which is in formula similar to Bergman's Ir compound used in hydrocarbon activation reaction, but might be more reactive because of its unsaturated electron structure. The crystal structure analysis of compounds 2, 3 and 4, showed that the ruthenium atom was coordinated in a "threeleg-piano-stool" geometry in all the three compounds. The Ru—Cl bond in 3 and 4 was lengthened, making it labile to other substitution reactions.  相似文献   

19.
When ketones were treated with ammonium chloride and Oxone~ in MeOH at room temperature,a directα-chlorination of ketones was occurred and a series of the corresponding a-chloroketones were obtained in moderate to good yields after 24 h.In this reaction,ammonium chloride was used as the source of chlorine and Oxone~ was used as an oxidant.This method was simple, convenient and providing a novel procedure for preparation of a-chloroketones.  相似文献   

20.
The 5'-nontranslated leader(omega sequence) of Tobacco mosaic virus(TMV) was used as a translational enhancer sequence in the expression of the hepatitis B surface antigen(HBsAg) gene in transgenic ginseng callus cultures. The adr subtype HBsAg gene was placed under the control of the Cauliflower mosaic virus(CaMV) 35S promoter linking to the TMV leader sequence. The antisense omega sequence was used in a control construct. The resulting constructs cloned in the binary vector pBI121 were used to transform the ginseng callus tissue via the Agrobacterium-mediated procedure. The integration and expression of the HBsAg gene were evaluated by PCR and western blot, respectively. Enzyme-linked immunoassays(ELISA) using a monoclonal antibody directed against human serum-derived HBsAg revealed a three to four-fold enhanced expression of HBsAg in ginseng cells conferred by the TMV omega element.  相似文献   

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