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A low temperature aqueous growth followed by mild pyrolysis was used in this study to synthesize high-quality carbonized materials from the deserted plant Citrullus Colocynthis. It was found that the carbon material prepared for this study contained an abundance of functional groups and surface active sites. A few microns were evidently the size of the carbon material. This study investigated a variety of photocatalytic performance evaluation parameters, including initial dye concentration of methylene blue, pH effect on dye solution, scavenger stability, and recycle stability via irradiating UV light. Methylene blue degradation was found to be significantly affected by pH and concentration of the dye solution. It has been found that pH five is the most effective pH for the removal of dyes. As a result of the study, we found that methylene blue decays according to pseudo first order kinetics and is estimated to remove dye at an almost 100% rate.

The development of new energy conversion and storage technologies has contributed to the widespread use of renewable energy. However, new methodologies for electrochemical energy storage systems remain to be developed. This study presents a facile, low-cost, scalable, and environmentally friendly method for the synthesis of nickel oxide (NiO) nanostructures by hydrothermal methods using lotus root extract. The different volumes of lotus root extract were tested on NiO nanostructures (sample 1, sample 2) using 1 ml and 2 ml amounts of the extract, respectively. Therefore, phytochemicals from lotus extract have influenced the surface morphology, crystal quality, optical band gap, electrical conductivity, and surface active sites of NiO nanostructures. Sample 2 of the NiO nanostructures was found to be highly active for oxygen evolution reaction (OER) and showed an overpotential of 380 mV at 10 mA cm ^−2 and a durability of 30 h at 10 mA cm ^−2 . Furthermore, sample 2 of NiO has shown specific capacitance of 1503.84 F g ^−1 at 2 A g ^−1 as well as cycling stability over a period of forty thousand GCD cycles. The percentage specific capacitance retention were highly improved up to 100.6%. An asymmetric energy storage device has been constructed using NiO sample 2 as the anode electrode material, demonstrating excellent specific capacity of about 1113 C g ^−1 at 5 A g ^−1 . For the asymmetric supercapacitor device, a power density of 20000 W kg ^−1 and an energy density of 245 Wh kg ^−1 were obtained. In a study of cycling stability for 40000 GCD cycles, it was observed that the asymmetric device retained 96.86% of its specific capacitance. A significant contribution was made to the electrochemical performance of sample 2 of NiO by phytochemicals derived from lotus extract.

The present study describes the use of a leaf extract from Ficus carica as a source of natural antioxidants for the surface alteration of bulk titanium dioxide (TiO2) in two steps. First, the hydro-thermal treatment of the bulk TiO2 material was carried out and followed by thermal annealing at 300 °C for 3 h in air. The role of the leaf extract of Ficus carica on the performance of the bulk TiO2 material for the removal of methylene blue (MB) was also studied. Various analytical techniques such as powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) were used to explore the crystalline structure, morphology, and composition. The bulk TiO2 material after the leaf-extract treatment exhibited mixed anatase and rutile phases, a flower-like morphology, and Ti, O, and C were its main elements. The average crystallite size was also calculated, and the obtained values for the bulk TiO2 material, 18.11 nm, and the treated bulk TiO2 material with various amounts, 5, 10, and 15 mL, of leaf extract were 16.4, 13.16, and 10.29 nm respectively. Moreover, Fourier-transform infrared spectroscopy validated the typical metal–oxygen bonds and strengthened the XRD results. The bulk TiO2 material chemically treated with Ficus carica has shown outstanding activity towards the degradation of MB under sunlight. The 15 mL of Ficus carica extract significantly enhanced the photocatalytic activity of the bulk TiO2 material towards the degradation of MB. The dye degradation efficiency was found to be 98.8%, which was experimentally proven by the Fourier Transform Infrared spectroscopoyy (FTIR) analysis. The obtained performance of the bulk TiO2 material with Ficus carica revealed excellent surface modifying properties for poorly-performing photocatalysts towards the degradation of synthetic dyes when used in their pristine form. The presented approach suggests that Ficus carica could be of great interest for tuning the surface properties of materials, either in the form of nano-size or bulk-phase in a particular application.