Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States.
Published: July 2017
AI Article Synopsis
Article Abstract
Metal macrocycles are among the most important catalytic systems in electrocatalysis and biocatalysis owing to their rich redox chemistry. Precise understanding of the redox behavior of metal macrocycles in operando is essential for fundamental studies and practical applications of this catalytic system. Here we present electrochemical data for the representative iron phthalocyanine (FePc) in both aqueous and nonaqueous media coupled with in situ Raman and X-ray absorption analyses to challenge the traditional notion of the redox transition of FePc at the low potential end in aqueous media by showing that it arises from the redox transition of the ring. Our data unequivocally demonstrate that the electron is shuttled to the Pc ring via the Fe(II)/Fe(I) redox center. The Fe(II)/Fe(I) redox transition of FePc in aqueous media is indiscernible by normal spectroscopic methods owing to the lack of a suitable axial ligand to stabilize the Fe(I) state.
Uniform, mesoporous copper(II) oxide nanospindles (CuO NSs) were synthesized via a method based on templated hydrothermal oxidation of copper in the presence of monodisperse poly(glycerol dimethacrylate--methacrylic acid) nanoparticles (poly(GDMA--MAA) NPs). Subsequent decoration of CuO NSs with a CaO nanoshell (CuO@CaO NSs) yielded a nanozyme capable of Cu(I)/Cu(II) redox cycling. Activation of the Cu(I)/Cu(II) cycle by exogenously generated HO from the CaO nanoshell significantly enhanced glutathione (GSH) depletion.
The electrochemical nitrate reduction reaction (NORR) involves multiple hydrogenation and deoxygenation steps, which compete with the hydrogen evolution reaction (HER). Therefore, NORR driven in acidic media is challenging in spite of advantageous fast hydrogen transfers in its elementary steps. The findings presented in this article first demonstrate that the NORR is significantly activated even in acidic lithium nitrate solutions at LiNO concentrations exceeding 6 m on a Pt electrode (the highly effective catalyst for HER) by the formation of a "hydronium-in-salt" electrolyte (HISE), a new type of aqueous high concentration salt electrolyte.
The optical detection of arsenic (As) in human biological fluids and environmental water samples is presented using alpha-cyclodextrin-modified silver nanoparticles (α/CyD-AgNPs) at the trace level. This method is based on the measurement of a red shift of the LSPR band of α/CyD-AgNPs in the region of 200-800 nm. The color of α/CyD-AgNPs was changed from yellow to colorless by the addition of As(iii).
The conductive polymeric electrodes using 3D printing are an innovative material development with the advantage of the flexibility of integrating isolated polymers with a higher electrical conductivity of carbon-based materials, generating new possibilities in environmental, healthcare, and food monitoring. Based on the morphology, geometric arrangement, and dielectric properties of the composites, the performance of the electrodes is improved. Structural designs are optimized to enhance functionalities such as adhesion, catalytic activity, and the reduction of interface energy.
Dyeing, Printing and Textile Auxiliaries Department, Textile Research and Technology Institute, National Research Centre, 33 EL Buhouth St., Dokki, 12622, Giza, Egypt.
Development of supercritical carbon dioxide (SC-CO) dyeing technology for natural fabrics and their blended fabrics is essential for the textile industry due to environmental and economic considerations. Wool (W), polyester (PET) and nylon (N) fabrics and their wool/polyester (W/PET) and wool/nylon (W/N) blended fabrics were dyed in SC-CO medium with a synthesized reactive disperse dye containing a vinylsulphone (VS) reactive group, which behaves as a disperse dye for synthetic fibers and a reactive dye for protein fibers. The SC-CO dyeing performance of all fabrics was investigated in terms of color strength, fixation, colorimetric and fastness measurements and compared with the conventional aqueous dyeing method.
