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In the present paper, the authors studied fluorescence resonance energy transfer (FRET) phenomenon between silver triangular nanoplates and bovine serum albumin (BSA)/Rhodamine 6G fluorescence complex, and established a fluorescence method for the detection of cobalt ions. We found that when increasing the silver triangular nanoplates added to certain concentrations of fluorescent bovine serum albumin (BSA)/Rhodamine 6G complex, the fluorescence of Rhodamine 6G would be quenched up to 80% due to the FRET between the quencher and donor. However, in the presence of cobalt ions, the disassociation of the fluorescent complex from silver triangular nanoplates occurred and the fluorescence of the Rhodamine 6G recovered. The recovery of fluorescence intensity rate (I/I0) has a good relationship with the cobalt ion concentration (cCO2+) added. Thus, the authors developed a fluorescence method for the detection of cobalt ions based on the FRET of silver triangular nanoplates and Rhodamine 6G.

The involvement of manganese radical for halogen atom transfer (XAT) reactions has been esteemed as one reliable method but encountered with limited catalytic models. In this paper, a novel bimetallic relay catalysis of Mn2(CO)10 and cobaloxime has been developed for divergent dehydrogenative difluoroalkylation of alkenes using commercially available difluoroalkyl bromides. A wide range of structurally diverse terminal, cyclic and internal alkenes as well as tetrasubstituted alkenes are found to be good coupling partners to deliver difluoroalkylated allylic products and difluoromethylated cyclic products, accompanied with the production of H2 as the by‐product. This bimetallic relay strategy features broad substrate scope, mild reaction conditions and excellent functional group compatibility. Its success represents an important step‐forward to expedite the construction of a rich library of difluoroalkylated products. [ABSTRACT FROM AUTHOR]

The effect of the incorporation of a third transition metal cation (Fe–O) and its concentration on the configuration of cobalt nickel oxide has been studied. An attempt has been made to synthesize hierarchical porous cobalt–nickel–iron ternary oxide heterostructure arrays by a simple two-step approach, which is a novel galvanostatic electrochemical technique, followed by calcination. The synthesized ternary oxide heterostructures have been targeted as an electrode for hybrid capacitor application due to their high redox potentials. A diaphragm cell was used for the electrodeposition of the ternary hydroxide at room temperature from a nitrate bath of the corresponding metal ions at a pH of 2. A series of experiments was carried out with a fixed concentration of Co (30 g dm−3) and Ni (30 g dm−3) while varying the concentration of Fe (10, 20 and 30 g dm−3) at the optimized pH of 2. The electrodeposited ternary metal hydroxides were calcined at an optimum temperature of 300 °C for 2 h to obtain the ternary oxide heterostructure. The formation of the ternary oxide heterostructure has been confirmed by X-ray diffraction analysis. The field emission scanning electron microscopy images suggest the formation of a hierarchical nanoflower architecture consisting of an interconnected flower petal with a porous surface and spherical nano crystallites at various Fe concentrations. Transmission electron microscopy supports the formation of nano crystallites with the size of ∼20 nm. Elemental analysis of the ternary oxides was carried out by using atomic absorption spectrophotometry, which suggests that all the materials contain Co, Ni, and Fe in various ratios. The result showed that with an increase in Fe concentration from 10 to 30 g dm−3 with the fixed concentration of Co and Ni, the % iron content in the ternary composite increases with a decrease in the concentration of Co and Ni. The increasing concentration of Fe in the metal oxide decreases the specific capacitance from 440 F g−1 to 272 F g−1, indicating a significant difference in the observed redox processes. However, the cycling stability for both these samples showed an excellent retention of over 92% after 1000 cycles. [ABSTRACT FROM AUTHOR]

Abstract: New cobalt-based metal oxide thin films (MxCoyOz with M=Mn, Cu, Ni) have been deposited on commercial aluminum and glass substrates using sol–gel dip-coating method. The as-deposited films were characterized by a wide range of complementary techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), spectrophotometry and nanoindentation techniques. A light absorption study for coatings on glass substrates within a wavelength range of 300–1100nm was also conducted. Topographical and morphological investigations showed the presence of nano-sized, grain-like particles in the copper–cobalt oxide coatings, which consequently had the roughest surface among the three coatings. All coatings on glass substrate exhibited higher absorption of ultraviolet (UV) light compared to visible light, while coatings on aluminum substrate generally had low reflectance (<50%) of UV light, moderate reflectance (<80%) of visible light and high reflectance (up to 100%) of infrared light. Implications of optical properties as a function of film thickness controlled by dip-heating cycles were discussed. The elastic modulus (E) and hardness (H) of thin film samples compared with stand‐alone commercial aluminum substrate were also measured. [Copyright &y& Elsevier]

[Display omitted] • Unique porous hollow carbon material with N-Co interacting with carbon nanotubes. • Electron-rich/poor reaction sites achieve efficient ozone catalysis. • Pollutants are efficiently removed: as electron donors and attacked by active species. • DFT calculation was used to reveal the catalytic mechanism. Metal − organic framework (MOF) derived carbon-based nanocatalysts have received great attention in environmental remediation applications. Herein, a hollow carbon polyhedron with nitrogen-coordinated cobalt embedded has been synthesized by thermal transformation of the core–shell structure ZIF-8@ZIF-67 (marked as ZIF-8@ZIF-67-C). Remarkably, the ZIF-8@ZIF-67-C catalyst could remove almost 98% of CH 3 SH after running for 60 min, exceeding the reported values (about 30 times higher than that of commercial MnO 2 catalysts). Elimination performance experimental results demonstrate that ZIF-8@ZIF-67-C has better anti-interference ability and anti-toxicity properties. The excellent catalytic performance can be attributed to the following facts: unique structure, high conductivity, abundant hierarchical porous structure, and accessible active sites. Theoretical calculation reveals the mechanism is that the Co-N electron bridge promotes Co nanoparticles adsorb O 3 , providing electrons to O 3 and producing 1O 2 to further oxidize CH 3 SH into CO 2 /SO 4 2−. Also, the ZIF-8@ZIF-67-C catalyst supported on Al 2 O 3 still shows excellent catalytic activity and durability, which deepened the practical application. This work provides a strategy for the development of MOF-on-MOF-derived metal/carbon hybrid materials in environmental applications. [ABSTRACT FROM AUTHOR]