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Author(s): Sna Rashid [sup.1], Ghulam Mustafa Peerzada [sup.1], Nadeem Bashir Ganaie [sup.1] [sup.2], Shafia Lateef [sup.1] Author Affiliations: (1) grid.412997.0, 0000 0001 2294 5433, Department of Chemistry, University of Kashmir, [...], Ion exchange resins are well known because of their vast applications in the processes like water softening, catalysis, waste water treatment, hydrometallurgy and chromatography. In the present investigation based on the interaction of different ion exchangers with ferroin to be used as catalyst in a nonlinear chemical reaction, quantitative estimation of Fe.sup.2+ was done by loading it on three different ion exchange resins, viz. Dowex Marathon C Na, Amberlite IRC86 and Dowex m4195 at different loading time intervals. The supernatant containing the residual ferroin was separated from ion exchange resins and added directly to the substrate molecule of the chemical oscillator as catalyst and the series of reaction systems were monitored by potentiometry and spectrophotometry and the results obtained were confirmed by advanced cyclic voltammetry as a supportive technique. Thus, the effect of catalyst after its interaction with ion exchange resins at optimal level was monitored. At the same time, it was found that the concentration of ferroin to be involved in the Belousov-Zhabotinsky reaction as a catalyst in the present interactive systems can be estimated up to 10.sup.-5 M and even lower, depending on the experimental conditions.

Anthropogenic CO2 emissions from fossil fuel combustion have led to the serious environmental consequence of global warming and associated climate change. Valorization of CO2 to value-added chemicals by electrochemical reduction has been suggested as one of the promising approaches of CO2 attenuation owing to its simple operational requirements and ambient process conditions. However, the sluggish kinetics and high overpotential of several CO2 reduction processes remain a challenge to its practical utility unless efficient electrocatalysts are applied. Over the past years, several electrocatalysts have been reported for the purpose with varying degree of success. In the current review, we critically evaluate the efficiency of various reported catalysts systems summarizing their advantages as limitations and providing insights into their mechanism of action. Based on the detailed review of different catalysts systems the outlook and future directions are proposed. [ABSTRACT FROM AUTHOR]

In this study, we prepared a polypyrrole-diphenyl diselenide [PPy/(PhSe) 2 ] nanocomposite by oxidative chemical polymerization for the purpose of temperature sensing applications. Fourier transform infrared spectroscopy, X-ray diffraction and scanning transmission electron microscopy confirmed the synthesis of the above material. Thermogravimetry (TG) revealed enhanced thermal stability as compared to pristine polypyrrole (PPy). Dielectric study showed the material to have a dielectric constant of colossal value. The material has been found to exhibit correlated barrier hopping conduction (CBH) wherein hopping of charge carriers takes place over the insulating (PhSe) 2 barrier. The maximum barrier height was found to be 0.224 eV. The nanocomposite material was found to exhibit a switching-type positive temperature coefficient (PTC) behavior with a Curie temperature of 400 K. This has been explained by a CBH model wherein PPy chains expand upon heating, thereby reducing the barrier height to facilitate current flow. However, above 400 K, disruption of PPy chains allows to reflect a PTC behavior. This has been in agreement with TG data., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)