AgBr@TiO2/GO (graphene oxide) ternary composite photocatalyst was synthesized by fabricating core–shell-structured AgBr@TiO2 and anchoring it onto the surface of GO. The obtained samples were characterized by transmission electron microscopy, X-ray diffraction analysis, X-ray photoelectron spectroscopy, ultraviolet–visible (UV–Vis) diffuse reflectance spectrum, and photoluminescence (PL) spectroscopy. It was found that the AgBr nanoparticles were prone to aggregation while the core–shell-structured AgBr@TiO2 possessed excellent dispersity. PL analysis revealed that the ternary-structured AgBr@TiO2/GO could effectively promote the separation rate of electron–hole pairs. Photocatalytic oxidation of benzyl alcohol to benzaldehyde under visible-light irradiation was selected as probe reaction to evaluate the photocatalytic activity of the different samples. It was found that the AgBr@TiO2/GO ternary composite exhibited evidently improved photocatalytic activity compared with AgBr, AgBr@TiO2, and AgBr/GO. On the basis of the experiment results, the photocatalytic oxidation mechanism of benzyl alcohol over AgBr@TiO2/GO is tentatively discussed. 相似文献
Well-dispersed Au/Bi nanoparticles with average size below 10 nm were prepared by using NaBH4 to reduce HAuCl4 with glucose as dispersant. The obtained Au/Bi NPs were well characterized by UV-Vis spectra, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and electrochemical measurements. The electrochemical study found that Bi adlayers on the surface of Au nanoparticles owns two kinds of surface structures, including a low coverage (2 × 2)-Bi adlayer and a close-packed (p × √3)-2 Bi adlayer due to the strong interaction between the two Bi layers and the below Au atoms, which is same with that bulk on Au surface. 相似文献
Crown ether complexes of sodium and potassium 2-(benzotriazol-2-yl)phenolates were synthesized and characterized. In the presence of BnOH these complexes are highly active catalysts for the controlled ring-opening polymerization of rac-lactide. The polymerizations are iso-selective and the Pm of polylactide reached 0.77 when the polymerization was performed in toluene at ?60°C; whereas heterorich-polylactide was obtained when the polymerization was carried out in CH2Cl2 or THF. 相似文献
Let {Xi = (X1,i,...,Xm,i)?, i ≥ 1} be a sequence of independent and identically distributed nonnegative m-dimensional random vectors. The univariate marginal distributions of these vectors have consistently varying tails and finite means. Here, the components of X1 are allowed to be generally dependent. Moreover, let N(·) be a nonnegative integer-valued process, independent of the sequence {Xi, i ≥ 1}. Under several mild assumptions, precise large deviations for Sn = Σi=1nXi and SN(t) = Σi=1N(t)Xi are investigated. Meanwhile, some simulation examples are also given to illustrate the results. 相似文献
The title complex [(C12H8N2)2Bi(O2NO)3] was synthesized by reaction of 1,10-phenanthroline (phen) and Bi(NO3)3·5H2O. The structure of the complex was characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental analysis. An advanced solution-reaction isoperibol microcalorimeter was applied to determine the standard molar enthalpies of formation at 298.15 K of the complex and Bi(NO3)3·5H2O, giving –(798.92 ± 5.99) and –(1986.87 ± 0.20) kJ mol−1, respectively. The biological effect of the complex was evaluated by microcalorimetry on the growth of Schizosaccharomyces pombe (S. pombe). According to thermogenic curves, the corresponding thermokinetics and thermodynamic parameters were derived. The complex had good bioactivity on the growth metabolism of S. pombe, with the value of IC50 being 2.8 × 10−5 mol L−1.
Journal of Solid State Electrochemistry - A hydrophilic polypyrrole/tellurium (PPy/Te) nanocomposite was synthesized by a facile approach in which H2TeO3 was used as the oxidizing agent of pyrrole... 相似文献
Two named reactions of fundamental importance and paramount utility in organic synthesis have been reinvestigated, the Barton decarboxylation and Giese radical conjugate addition. N ‐hydroxyphthalimide (NHPI) based redox‐active esters were found to be convenient starting materials for simple, thermal, Ni‐catalyzed radical formation and subsequent trapping with either a hydrogen atom source (PhSiH3) or an electron‐deficient olefin. These reactions feature operational simplicity, inexpensive reagents, and enhanced scope as evidenced by examples in the realm of peptide chemistry. 相似文献
Recently, we developed methods to stabilize peptides into various secondary structures, including α‐helix, type III turn and β‐hairpin via proper thioether based macrocyclization. These conformationally constrained peptidomimetics confer enhanced biophysical properties and provide a valuable avenue towards clinically‐relevant therapeutic molecules. In this personal account, thioether‐derived macrocyclization methods developed by our group for stabilization of α‐helix, type‐III β turn and β‐hairpin conformations are discussed. 相似文献