In this work, we produced nickel oxide nanostructures that show high electrochemical capacitive behaviour, using fungus-one of the most common life forms in nature. Cladosporium cladosporioides fungi are particularly attractive biotemplates due to their tubular structures. The nanostructured porous microtubes were prepared by chemical precipitation onto fungi. The morphological properties of the biosynthesized NiO microtubes were studied by transmission electron microscope (TEM). The Brunauer-Emmett-Teller (BET) surface area was found to be 119.72 m 2 g-1 with an average pore size distribution of 7.5 nm. A maximum capacitance value of 334 F g-1 was observed at 0.8 A g-1 , and a capacitance retention of approximately 95% was obtained after 1000 cycles.

Recently, plant pollen has been used as a source of activated carbon to produce carbon-containing supercapacitor electrodes. However, in this study, pollen was used as a biotemplate with a completely different approach. As a biotemplate, pollen offers a wide range of varieties in terms of exterior, porosity, shape, and size. An electrode formed by the use of metal oxide grown on the pollen exine layer (sporopollenin microcapsules) as the active substance will inevitably exhibit good electrochemical capacitive properties. Juglans male flowers have been distinguished by dissection from anthers. Isolation of pollen grains from anthers was carried out using sieving from suitable sieves (45–200 μm). Juglans sporopollenin exine microcapsules (SECs) were separated from the intine and protoplasm by acetolysis in combination with reflux. The solution containing SECs, metal ions, and Ni foam was put into a Teflon-lined hydrothermal container, and then, it was reacted at 120 °C for 15 h. The resulting precipitate, as well as the Ni foam, was heat-treated at 300 and 360 °C for 3 h in air. The raw pollen, chemically treated pollen, and cobalt-coated SEC (CoSEC) and CoSEC/Ni foam were characterized using scanning electron microscopy, Brunauer–Emmett–Teller surface area analysis, thermogravimetric analysis, and X-ray diffraction techniques. Two different types of supercapacitor electrode designs, with the use of exine microcapsules of Juglans sporopollenin, were performed for the first time. The maximum specific capacitance was up to 1691 F g –1 at 5 A g –1 .

In this work, nanostructured La-based materials were produced by chemical precipitation method onto Cladosporium cladosporioides fungal hyphae in aqueous solution. Materials were annealed at various temperatures between 100• C-600• C. The morphological properties of the synthesized material were studied by transmission electron microscopy. The surface area for sample annealed at 360• C was determined to be 85.64 m 2 /g using Brunauer-Emmett-Teller method. The nitrogen adsorption and desorption isotherm displayed a typical type-IV isotherm. Electrochemical properties of produced material were studied using cyclic voltammetry, long term charge/discharge analysis and impedance spectroscopy in the 0.5 M Na2SO4 electrolyte. The obtained nanostructured porous electrode exhibits quasi-rectangular shaped cyclic voltammetry curves with a specific capacitance of 2190 F/g at a scan rate of 2 mV/s.