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Solid polymer electrolytes (SPEs) for symmetrical supercapacitors are proposed herein with activated carbon as electrodes and optimized solid polymer electrolyte membranes, which serve as the separators and electrolytes. We propose the design of a low-cost solid polymer electrolyte consisting of guanidinium nitrate (GuN) and poly(ethylene oxide) (PEO) with poly(vinylpyrrolidone) (PVP). Using the solution casting approach, blended polymer electrolytes with varying GuN weight percentage ratios of PVP and PEO are prepared. On the blended polymer electrolytes, structural, morphological, vibrational, and ionic conductivity are investigated. The solid polymer electrolytes' morphology and level of roughness are examined using an FESEM. The interlinking bond formation between the blended polymers and the GuN salt is verified by FTIR measurements, indicating that the ligands are chemically complex. We found that, up to 20 wt.% GuN, the conductivity value increased (1.84 × 10−6 S/cm) with an increase in mobile charge carriers. Notably, the optimized PVP/PEO/20 wt.% solid polymer electrolyte was fabricated into a solid-state symmetrical supercapacitor device, which delivered a potential window of 0 to 2 V, a superior energy density of 3.88 Wh kg−1, and a power density of 1132 W kg−1. [ABSTRACT FROM AUTHOR]

Metal oxide-based electrode materials and redox additive electrolytes hold great promise as essential components of energy storage devices and have a great impact on their overall performance. Co3O4 nanoflakes (NFs) have been prepared by a simple hydrothermal method. After thorough characterization of structure, functional group, and surface morphology, the potential of the as-prepared Co3O4 NFs is assessed as an electrode material for a supercapacitor. The powder XRD analysis confirms the formation of the spinel cubic phase and space group Fd 3 ‾ m. Morphological studies showed prepared Co3O4 having nanoflakes-like structures and, with analysis by EDX, the presence of elemental composition has been confirmed. The electrochemical performance of the Co3O4 electrodes has been studied in three electrode configurations using a redox-additive electrolyte. The electrode demonstrates enhanced supercapacitor performance with a redox additive electrolyte due to the reversible oxidation states of Co2+/Co3+ and Fe2+/Fe3+, which significantly reinforced the Faradaic redox reaction. The CV curve has maintained its shape even at all scan rates, confirming the outstanding rate capability of the electrode. The Co3O4 electrode showed a greater specific capacitance (Csp) of 611.16 F g−1 at a current density of 10 A g−1 in a redox additive electrolyte solution and capacitance retentions up to 69.23 % after 10,000 cycles. The calculated charge transfer resistance (Rct) of before and after GCD 10,000 cycles is obtained. The overall performance of the electrode material being consider as a promising candidate for supercapacitor applications. [ABSTRACT FROM AUTHOR]

Developing a robust material holding antimicrobial assets has been an efficient strategy for reducing the risk of infections related to healthcare, significantly with medical devices and touch surfaces. Molybdenum-based compounds have drawn momentous attraction because of their unique characteristics. A series of undoped and 5 % rare earth (Ce & La) doped metal (Ni, Co & Bi) molybdate nanocomposites have been prepared by facile microwave combustion method and characterized. The present study investigates the effect of dopants on crystal structure and morphology, and their impact on anti-bacterial properties is noticed. The UV–Vis. absorption spectra of all samples show a broad absorption band between 280 and 430 nm. The antibacterial properties of the prepared nanocomposites have been examined by the agar diffusion method against three Gram-positive and two Gram-negative bacteria, showing good bactericidal efficiency for all samples, except 5 % Ce–NiMoO4 (antibacterial activity exclusively against Gram-positive bacteria) and 5 % La–NiMoO4 (no antibacterial activity) nanocomposites. This work provided a novel pathway in the biomaterial field. [ABSTRACT FROM AUTHOR]

Novel flake-like Ni1−xSnxO2 particles were successfully prepared by template-free hydrothermal synthesis. The prepared samples were investigated for their properties by different characterization techniques. Scanning micrographs showed that the obtained particles consisted of nanoflakes. The X-ray diffraction results of the Ni1−xSnxO2 revealed the formation of mixed-phase Ni/SnO2 having the typical tetragonal structure of SnO2, and the cubic structure of Ni in a nanocrystalline nature. The doping with Ni had a certain influence on the host's lattice structure of SnO2 at different doping concentrations. Confirmation of the functional groups and the elements in the nanomaterials was accomplished using FTIR and EDS analyses. The electrochemical performance analysis of the prepared nanomaterials were carried out with the help of the CV, GCD, and EIS techniques. The specific capacitance of the synthesized nanomaterials with different concentrations of Ni dopant in SnO2 was analyzed at different scanning rates. Interestingly, a 5% Ni-doped SnO2 nanocomposite exhibited a maximum specific capacitance of 841.85 F g−1 at 5 mV s−1 in a 6 M KOH electrolyte. Further, to boost the electrochemical performance, a redox additive electrolyte was utilized, which exhibited a maximum specific capacitance of 2130.33 at 5 mV s−1 and an excellent capacitance retention of 93.22% after 10,000 GCD cycles. These excellent electrochemical characteristics suggest that the Ni/SnO2 nanocomposite could be utilized as an electrode material for high-performance supercapacitors. [ABSTRACT FROM AUTHOR]