In practical scenarios, viologen-derivatives face an accelerated degradation in the unavoidable presence of traces of oxygen in large-scale redox flow batteries. Herein, we confirm the primary degradation mechanism and propose a straightforward, cheap, and fast method to evaluate the stability of viologen-derivatives toward this degradation. Considering that the cleavage of the N-substituent is the main proposed pathway for viologen degradation, a new viologen-derivative, bearing an alkylsulfonate chain with a secondary carbon center joined to the N atom, is synthesized to illustrate how molecular engineering can be used to improve stability.
View Article and Find Full Text PDFBoth multi-walled carbon nanotubes (MWCNTs) and metal or metal oxides have demonstrated virus removal efficacy in drinking water applications. In this study, MWCNTs were coated with copper(I) oxide (CuO) using three distinct synthesis procedures (copper ion attachment, copper hydroxide precipitation, and [Cu(NH)] complex attachment) and virus removal efficacy (using MS2 bacteriophages) was evaluated. All synthesis procedures resulted in the presence of adsorbed, nanosized CuO particles on the MWCNTs, shown using X-ray diffraction.
View Article and Find Full Text PDFLithography-based ceramics manufacturing (LCM) processes enable the sophisticated 3 dimensional (3D) shaping of ceramics by additive manufacturing (AM). The build-up occurs, like many other AM processes, layer by layer, and is initiated by light. The built-in digital mirror device (DMD) enables the specific exposure of desired pixels for every layer, giving as a consequence a first estimation of the printing resolution in the x and y axes.
View Article and Find Full Text PDFPerovskite oxides have been at the forefront among catalysts for the oxygen evolution reaction (OER) in alkaline media offering a higher degree of freedom in cation arrangement. Several highly OER active Co-based perovskites have been known to show extraordinary activities and stabilities when the B-site is partially occupied by Fe. At the current stage, the role of Fe in enhancing the OER activity and stability is still unclear.
View Article and Find Full Text PDFTiO(2) and TiO(2)/Er(3+) nanoparticulate sols were obtained by the colloidal sol-gel route. Thanks to the combination of three optical techniques (laser diffraction, LD, dynamic light scattering, DLS, and multiple light scattering, MLS), the peptization time was quantified, demonstrating that erbium(III) ions retard the process. The isoelectric point of TiO(2) shifts up to higher pH's when Er(3+) ions are present, which suggests that they are adsorbed onto the surface of the TiO(2) nanoparticles.
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