In this study, a novel potential-triggered electroactive composite film consisting of mesoporous silica SBA-15, polyaniline (PANI), and polystyrenesulfonate (PSS) was fabricated in an aqueous electrolyte solution via a facile pulse potentiostatic method. The obtained composite film was characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric (TG) analysis, and scanning electron microscopy (SEM). The ion exchange properties were evaluated in a solution containing 0.1 M Pb(NO3)2 by using an electrochemical quartz crystal microbalance (EQCM) as well as cyclic voltammetry (CV) method. It was found that the uptake/release of Pb2+ ions in/from SBA-15/PANI/PSS composite film was successfully achieved by modulating the redox states of the electroactive composite film, and the composite film exhibited different ion exchange behaviors at different scan rates. Based on these results, the ion exchange mechanism was proposed. Compared with the PANI/PSS composite film, the SBA-15/PANI/PSS composite film had higher adsorption capacity as well as higher selectivity toward Pb2+ ions, which should be attributed to the 3D porous morphology of the composite film with more active sites in the mesoporous SBA-15. Remarkably, the film maintained a high stability over 97% even after 500 successive cycles. It is expected that this SBA-15/PANI/PSS composite film can serve as a promising electroactive material for the effective separation of Pb2+ ions from wastewater.
The efficiency of impregnation methods for making Cu-based solid oxide fuel cells (SOFCs) is qualitatively characterized for the first time through a conformal coating model. It is found that the low-efficiency results from the uneven distribution of Cu instead of the small loading. Most of the Cu deposits form isolated islands, e.g., in a 20.4 vol.% Cu-loaded anode, 81% Cu is isolated from each other. In order to address the limited impregnation efficiency, two different procedures are adopted to fabricate the practical Cu/CeO2 anodes, namely, simultaneous and sequential impregnation procedures. It is found that CeO2 works as a solid dispersant, improving the Cu distribution drastically. Compared to the Cu-only anode, more than a threefold improvement of impregnation efficiency is achieved by both methods. The anode made by the sequential impregnation yields the best performance in CH4 at 700 °C, 170 mW cm?2, which represents an 18% enhancement over that of the simultaneous impregnation, or 340% over the Cu-only anode. These findings demonstrate that it is of importance to optimize the Cu impregnation to yield a highly active anode, and the sequential impregnation method is a promising procedure to break the efficiency-limiting factor and produce a high-performance anode with minimized fabrication effort. 相似文献
A thermo- and pH- dual responsive luminescent hydrogel was successfully constructed by coupling dysprosium-containing polyoxometalates Na9DyW10O36 (DyW10) with the ABA triblock copolymer, where the B block is PEO and the A block is the thermosensitive poly(methoxydi(ethylene glycol) methacrylate-co-N,N-dimethylaminoethyl methacrylate). The complex hybrid underwent a sol-gel phase transition above the lower critical solution temperature (LCST) of the A block. DyW10 was electrostatically encapsulated into the hydrophobic domain of the A block with enhanced photoluminescence. When temperature cooled down, the luminescence could be restored. By addition of acids to protonate the A block, and emission of DyW10 was simultaneously enhanced. Sensitivity of poly(N,N-dimethy laminoethyl methacrylate) (PDMAEMA) to pH also enabled the emission of DyW10/copolymer hydrogel to be reversibly switched by alternating acid/base treatments. 相似文献
This paper discusses the oscillation of solutions for systems of nonlinear neutral type parabolic partial fuctional differential equations of the form 相似文献
Selective catalytic reduction (SCR) of nitric oxide with propane in excess oxygen was investigated on Ni-ZrO2 (NZ) and sulfated Ni-ZrO2 (SNZ), prepared by coprecipitation from a mixture of nickel nitrate-zirconium oxychloride followed by modifying with (NH4)2SO4. It was found that sulfated Ni-ZrO2 catalyst showed higher activity for the SCR of NO with propane than that of Ni-ZrO2. The structural and surface properties of catalysts were studied by XRD, BET, SEM and FT-IR of pyridine adsorption. The experimental results indicated that the modification of (NH4)2SO4 resulted in the generation of strong BrOnsted and Lewis acid sites and promoted the dispersion of the Ni species, which could lead to higher NO conversion and propane efficiency in NO reduction. 相似文献
Retarding grid and Fourier transform ion cyclotron resonance (FTICR) mass spectrometry variable trap potential measurements are performed to determine factors that contribute to the kinetic energy distribution of ions formed in an electrospray source that uses a heated capillary for desolvation. The control of ion kinetic energies is achieved by manipulating the skimmer position in the postcapillary expansion and by varying the potential appEed to the skimmer. The selective generation of either charge-dependent or charge-independent ion energy distributions is demonstrated. Charge-dependent energy distributions of electro-sprayed ions are created by sampling ions near the Mach disk of the supersonic expansion and by using a larger diameter skimmer orifice; the FTICR spectra acquired under these conditions exhibit mass-to-charge ratio-dependent mass discrimination determined by the potential used to trap the ions. Charge-independent energies of electrosprayed ions are created by positioning the capillary adjacent to the skimmer to sample thermal ions and by using a smaller skimmer orifice to reduce expansion cooling; under these conditions ion kinetic energy is determined primarily by the skimmer potential and no mass-to-charge ratio-dependence is observed in the selection of optimum FTICR trapping conditions. The ability to select between proteins of different conformation on the basis of kinetic energy differences is demonstrated. For example, a 0.4 V difference in trap potential is observed in the selective trapping of open and closed forms of the +10 charge state of lysozyme. Finally, it is demonstrated that by operating the source under conditions which deliver a beam of ions with charge-independent energies to the cell, it is possible to obtain precursor and product ion signal magnitudes in FTTCR spectra without charge-dependent mass discrimina-tion. 相似文献
The incorporation of H(3)N(CH(2))(7)NH(3) with CH(3)NH(3)SnI(3) resulted in the formation of a mixed-valent and semiconducting (Eg = 0.84 eV) organic-based perovskite, [H(3)N(CH(2))(7)NH(3)](8)(CH(3)NH(3))(2)Sn(iv)Sn(ii)(12)I(46), with a unique 3D defect-perovskite structure with ordered vacancies at the Sn and I sites. 相似文献