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Flexible and environmentally safe electrodes are high in demand for modern energy storage devices. This study reports the fabrication of cerium oxide (CeO2) and cerium oxide-manganese oxide nanoparticles (Ce0.98Mn0.02O2NPs) via co-precipitation synthesis technique and further development of bendable paper-based energy storage electrodes by employing lignocelluloses fibers as binder, extracted from self-growing plant, Monochoria Vaginalis. The structural and optical properties of the prepared products are carried out by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). XRD study reveals that Mn ions are incorporated into the CeO2lattice to synthesize the Ce0.98Mn0.02O2nanoparticles. SEM/EDX and TEM/SAED are performed for surface morphological analysis and successful composite formation of CeO2/LC and Ce0.98Mn0.02O2/LC sheets. Electrochemical measurements of CeO2/LC and Ce0.98Mn0.02O2/LC composite sheets were performed where fabricated sheets were employed as freestanding working electrode in 2 M KOH electrolyte. CeO2/LC and Ce0.98Mn0.02O2/LC composite sheets have shown specific capacitances of 401.5 and 544 F/g, respectively from three electrode cyclic voltammetry (CV) measurements. 2-electrodes galvanostatic charge–discharge (GCD) measurements were performed in symmetric cell which reveal the capacitance of 436 F/g and 560 F/g for CeO2/LC and Ce0.98Mn0.02O2/LC composite paper sheets, respectively. The Ce0.98Mn0.02O2/LC (1:1) composite paper sheet shows the capacitance retention stability up to 80% after 1000 cycles at applied current density of 3.3 A/g. It can conclude that the fabricated paper electrodes can employ as working electrodes in modern energy storage devices having dual advantages of flexible and environmentally safe characteristics in the absence of any synthetic substrate/binder.

Zinc oxide (ZnO) nanostructures were synthesized via a one‐step solid‐state reaction approach in ammonia (NH3) gas environment with different temperature ramp rates. The so‐formed nanostructures were characterized using X‐ray diffraction (XRD) for phase identification, where the typical wurtzite hexagonal structure was observed. Scanning electron microscopy (SEM) confirmed the particle size to be in the range 45–50 nm, the same as calculated by the XRD pattern for the ramp rate of 10 °C/min. Energy dispersive X‐ray (EDX) spectroscopy and X‐ray photoelectron spectroscopy (XPS) confirmed the chemical purity of the samples. The photoluminescence (PL) spectrum indicated multiple near‐band‐edge emissions and energy‐band emissions. Then, these ZnO nanomaterials were used for the degradation of crystal violet (CV) dye under UV light irradiation. The CV solution was completely degraded in 2 hr. The initial photocatalyst and dye amounts of 0.2 g/100 ml and 0.5 mg/L, respectively, were found to be the optimum values for maximum degradation efficiency. The ZnO‐based photocatalyst was stable up to three cycles of reuse. These results indicate that the high surface area and porosity of the nanomaterials are responsible for the high efficiency, which was confirmed by specific surface area analysis. In this study, Zinc oxide nanomaterials have been prepared by one step solid state reaction method. Photocatalytic efficiency of synthesized nanomaterials have been evaluated by degrading crystal violet dye under UV light irradiation.

In the era of modern disposable electronic technology, flexible substrate materials are excessive in demand due to foldable, bendable and stretchable choices. This paper reviews the research undertaken on flexible substrates particularly employed in high-tech applications of radio frequency and antenna design technologies. Irrespective of traditional applications, natural fibrils based substrates are considered most promising candidates as substrates for next-generation electronic applications due to abundant, low profile, light-weight, flexible and environment safe characteristics. This paper also presents a comprehensive study of the design and methods that have been applied to use mentioned materials in radio frequency applications. Several challenges are highlighted in the large-scale production and deployment of these technologies in real-world systems.

In order to obtain an efficient electrode material with large ion-exchange capacity, we chemically polymerized a thin (~30-50 nm) PPy layer on a high surface area Cladophora sp. algae cellulose substrate. The resulting composite had the appearance of a black flexible paper sheet with good mechanical strength, large specific surface area (80 m2/g), and high electron conductivity (~2 S/cm). The latter material was previously utilized as an electrode material for efficient (and fully reversible) separation of inorganic (chloride and nitrate) and organic (p-toluenesulfonate) anions. The oxidation of these PPy conducting paper electrodes also resulted in the inclusion of single stranded d(T)6 hexamers as a counter ion into the film even in the presence of large amounts of other competitor anions. In this study carbon chopped fibers (CCF) were incorporated with the PPy-cellulose nano fibers to improve the reversibility of the electrochemically controlled DNA separation. The addition of CCF into above material increased the electron transfer mechanism among the PPy sites during reduction state. The outcome of the above-described investigations showed a partial reversibility of the electrochemically-controlled DNA extraction accounting to ~45% recovery from the extracted amount. The PPy composite paper electrode material can thus serve as a new technology platform for developing electrochemically-controlled separation techniques in biotechnology, nanoanalytical systems, paper-based diagnostic devices, and immunosensors.

•Hydrothermal synthesis of GO based nickel sulfide nanoplates.•Electrode structure showed excellent specific capacitance 1745.50 Fg−1and energy density 87.30 WhKg−1.•Two electrodes symmetric measurements revealed good energy density of 15.72 WhKg−1.•GO based nickel sulfide can be engaged effectively for pseudocapacitor applications.

In order to obtain an efficient electrode material with large ion-exchange capacity, we chemically polymerized a thin (~30-50 nm) PPy layer on a high surface area Cladophora sp. algae cellulose substrate. The resulting composite had the appearance of a black flexible paper sheet with good mechanical strength, large specific surface area (80 m2/g), and high electron conductivity (~2 S/cm). The latter material was previously utilized as an electrode material for efficient (and fully reversible) separation of inorganic (chloride and nitrate) and organic (p-toluenesulfonate) anions. The oxidation of these PPy conducting paper electrodes also resulted in the inclusion of single stranded d(T)6 hexamers as a counter ion into the film even in the presence of large amounts of other competitor anions. In this study carbon chopped fibers (CCF) were incorporated with the PPy-cellulose nano fibers to improve the reversibility of the electrochemically controlled DNA separation. The addition of CCF into above material increased the electron transfer mechanism among the PPy sites during reduction state. The outcome of the above-described investigations showed a partial reversibility of the electrochemically-controlled DNA extraction accounting to ~45% recovery from the extracted amount. The PPy composite paper electrode material can thus serve as a new technology platform for developing electrochemically-controlled separation techniques in biotechnology, nanoanalytical systems, paper-based diagnostic devices, and immunosensors.