[en] In era of modern disposable and bendable energy storage technology, flexible and environmentally safe electrodes are extremely feasible. This study elaborates the synthesis of highly flexible and stretchable polymer gel membrane by covalently cross linking of chitosan (CS) and poly vinyl alcohol (PVA) immobilized MnO₂ for efficient, light-weight and cost-effective energy storage technologies. Fourier transform infrared spectroscopy (FTIR) revealed the existence of CS/PVA as well as MnO₂ in original form without any chemical change. 3-dimensional morphology including porosity of the presented fabricated membranes are examined by scanning electron microscopy (SEM). Presented CS/PVA based MnO₂ membranes were bendable and can be cut in any shape by the simple usage of scissor to employ by means of working electrode. Furthermore, electrochemical behaviour was tested by cyclic voltammetry (CV) and Galvanostatic charge/discharge (GCD) measurements in neutral/acidic electrolytes. CS/PVA based MnO₂ membranes showed excellent capacitive behaviour with specific capacitance of ∼140 F g⁻¹. GCD measurements also verified efficient kinetics of charging/discharging at low and high current rates as curves were symmetric. Presented flexible and electroactive CS/PVA based MnO₂ membranes will be highly suitable candidates for bendable electrode material in modern high-tech flexible energy storage devices. (paper)

[en] The authors report on the synthesis of carboxy functionalized graphene oxide (fGO) decorated with magnetite (Fe₃O₄) nanoparticles. The resulting nanomaterial was used to prepare a composite with polyaniline (PANI) which was characterized by UV-vis, Fourier transform-infrared and Raman spectroscopies. Its surface morphologies were characterized by atomic force and scanning electron microscopies. A screen-printed carbon electrode was then modified with the nanocomposite to obtain an enzyme-free glucose sensor. The large surface of fGO and Fe₃O₄ along with the enhanced charge transfer capability of PANI warrant a pronounced electrochemical response (typically measured at 0.18 V versus Ag/AgCl) which is suppressed in the presence of glucose. This reduction of current by glucose was used to design a sensitive method for quantification of glucose. The response of the modified SPCE is linear in the 0.05 μM – 5 mM glucose concentration range, and the lower detection limit is 0.01 μM.

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