[Cu2(UO2)4(suc)4(pac)4] (1), [(Cu(H2O)2)(4,4′-bipy)2][(UO2)2(H2O)2(Hca)2]·3H2O (2), and [(Cu(H2O)2)(UO2)(bta)]·4H2O (3) were synthesized by the reaction of succinic acid and 3-pyridinecarboxylic acid, citric acid and 4,4′-bipyridine, or 1,2,4,5-benzenetetracarboxylic acid ligands with Cu(NO3)2·3H2O and UO2(CH3COO)2·2H2O. The complexes were characterized by IR and UV–vis spectroscopy, powder X-ray diffraction, single-crystal X-ray diffraction, and photoluminescence spectroscopy. Photocatalytic activities of the complexes were also investigated. 相似文献
Two novel phosphonate compounds (H2L)·Hphen (1) and [Ca(HL)(H2O)]n·3.5nH2O (2) (L = N(CH2PO3H)33?) were synthesized under hydrothermal conditions. Compound 1 features a chain structure in the ac plane, where HL2? anions are interconnected through sharing hydrogen ions to form a 1D zigzag type. Compound 2 features a layered structure in the ab plane, which has inorganic calcium cores with the organic part of the phosphonate anions being encircling the cores through coordination actions. The free water molecules can form hydrogen bonds with the coordinated water molecules and phosphonate oxygen atoms, which are able to link the adjacent layers to generate a 3D network structure. In addition, the thermal stability and photoluminescence properties were also studied. 相似文献
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
Three fluorescent BINOL-Si complexes (FS1, FS2 and FS3) were rationally designed and synthesized to detect diethyl chlorophosphate (DCP), a mimic of lethal nerve agents. These three fluorescent probes showed green, yellow and orange fluorescence, respectively. Moreover, the series of fluorescent probes has the characteristics of fast response time (≤4 s), low detection limit (0.0097 μmol/L), high sensitivity and naked eye detection. More important, a fiber optic sensor capable of detecting DCP vapor in real time was also prepared for the first time, the lowest detection limits (down to 4.4 ppb) were all lower than that of the IDLH (immediately dangerous to life or health) concentration of Sarin (7.0 ppb). 相似文献
Reduced graphene oxide hollow microspheres (rGO HMS) were encapsulated with gold nanoparticles (AuNPs) by spray drying. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Raman spectroscopy were used to characterize the AuNP/rGO HMS. When placed on a glassy carbon electrode (GCE), it exhibits excellent electrochemical catalytic properties towards the oxidation of nitrite. The electrocatalytic properties were studied using various electrochemical techniques. Compared to AuNP-decorated graphene sheet based electrodes documented in the literature, the one presented here provides a larger surface area. This enhances the catalytic activity towards nitrite. The electrode, typically operated at a working potential of 0.82 V (vs. SCE), has a linear response in the 5.0 μM to 2.6 mM nitrate concentration range, and a detection limit as low as 0.5 μM (at an S/N ratio of 3).
Graphical abstract Schematic presentation of the synthesis of graphene hollow microspheres encapsulated with of gold nanoparticles (AuNP/rGO HMS) through a spray drying technique. The material was applied to the electrochemical determination of nitrite.
The Rose Bengal sensitized intermolecular [2 + 2]-cycloaddition of 3-ylideneoxindoles for the synthesis of spirocyclic oxindoles was developed successfully under visible light irradiation conditions. The cycloaddition products were obtained in good yields (up to 93%) with excellent diastereoselectivity and regioselectivity by using a low loading of Rose Bengal (0.125 mol%) as a triplet sensitizer. This work demonstrates the potential benefits of Rose Bengal in visible light catalysis. 相似文献
