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To produce clean energy due to the lack of fossil fuels, the development of cost-effective and highly efficient energy storage devices and multifunctional electrocatalysts is essential to substitute noble metal-based electrocatalysts. In this context, transition metal-based nickel phosphonate material (NiNAP) has been synthesized using 1,1′-binaphthyl-2,2′-diyl hydrogenphosphate and nickel nitrate hexahydrate in a hydrothermal reaction pathway in the absence of a templating pathway. The organic− inorganic hybrid structure with microporous arrays as a potential electrode material facilitates energy storage and conversion reactions. For the first time, a sphere-like NiNAP material has been developed, which is a potential electrode material for asymmetric supercapacitor applications with high specific capacitance and both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) with a low overpotential and higher current density. Moreover, the NiNAP material exhibits a specific capacitance of 4456 F g −1 in three-electrode assembly and 455 F g −1 in asymmetric supercapacitor at a scan rate of 1 mV s −1 , where the energy and power density are estimated to be 204 W h kg −1 and 409 W kg −1 , respectively. Interestingly, the NiNAP material displays outstanding catalytic activity toward OER with a low overpotential of 242 mV at the current density of 10 mA cm −2 and excellent ORR activity with an onset potential of 0.74 V vs RHE. Also, it shows long-term stability without significant changes in the current density for OER and ORR.

Fly ash generated from coal based thermal power plants creates environmental problems due to improper utilization and disposal. The present study was conducted to study the effects of various concentrations of FA (20, 40, 60, 80 and 100%) on the growth and photosynthetic activity of Oryza sativum (rice) and Zea mays (maize). Plant growth was mostly enhanced in the treatments with 20-40% fly ash, being optimal at 60%. From 80% onwards, the measured parameters tended to reduce. The most economic level of fly ash incorporation was 60%, which improved the growth of maize and rice. Hence fly ash can be utilized as a substrate or as a soil ameliorating material for the growth of plants, leading to the sustainable utilization of solid waste material.

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