Ionic Liquid-assisted Synthesis of Polyaniline/Gold Nanocomposite and Its Biocatalytic Application

In this report, a novel chemical synthesis of polyaniline/gold nanocomposite is explored using ionic liquid (IL) 1-Butyl-3-methylimidazolium hexafluorophosphate. The direct chemical synthesis of polyaniline/gold nanocomposite was initiated via the spontaneous oxidation of aniline by AuCl4−in IL. A nearly uniform dispersion of polyaniline/Au particles with a diameter of 450 ± 80 nm was produced by this method, which indicates that this method is more suitable for controlling particle dimensions. It was also found that the electrical conductivity of the polyaniline/gold nanocomposite was more than 100 times higher than that of the pure polyaniline nanoparticles. The polyaniline/gold nanocomposite displays superior function in the biocatalytic activation of microperoxidase-11 because of the high surface area of the assembly and the enhanced charge transport properties of the composite material. We also report the possible application of polyaniline/gold nanocomposite as a H2O2biosensor

The role of internally financed capex in rising Chinese corporate debts

International audienceThis paper aims to identify potential drivers behind China's rising corporate leverage, using an international aggregate panel dataset. We find strong evidence of significantly negative effects of the internally financed share of capital expenditure on the change of corporate debt/GDP: a rise in internally generated funds relative to gross capital formation consistently slows corporate debt buildup. While our core finding is robust to choices of benchmark models, control variables, and data samples, this negative effect appears more pronounced in China's case. Our regressions also suggest more important roles played by real economic factors than monetary factors. While the investment rate contributes to rising corporate debt, a higher saving rate dampens corporate leveraging. Finally, we present some evidence of consistently negative impacts of government debt on corporate leveraging, suggesting possible interactions between corporate and government debts. Overall, our empirical evidence points to the declining investment efficiency as a possible important driver behind China's high and rising corporate leverage, in light of its high investment rate and low internally funded capex ratio

Easy preparation of SnO2@carbon composite nanofibers with improved lithium ion storage properties

SnO2@carbon nanofibers were synthesized by a combination of electrospinning and subsequent thermal treatments in air and then in argon to demonstrate their potential use as an anode material in lithium ion battery applications. The as-prepared SnO2@carbon nanofibers consist of SnO2 anoparticles/nanocrystals encapsulated in a carbon matrix and contain many mesopores. Because of the charge pathways, both for the electrons and the lithium ions, and the buffering function provided by both the carbon encapsulating the SnO2 nanoparticles and the mesopores, which tends to alleviate the volumetric effects during the charge/discharge cycles, the nanofibers display a greatly improved reversible capacity of 420 mAh/g after 100 cycles at a constant current of 100 mA/g, and a sharply enhanced reversible capacity at higher rates (0.5, 1, and 2 C) compared with pure SnO2 nanofibers, which makes it a promising anode material for lithium ion batteries