Green Synthesis of ZnO Nanoparticles and Ag-Doped ZnO Nanocomposite Utilizing Sansevieria trifasciata for High-Performance Asymmetric Supercapacitors.

This study provides a comprehensive analysis of a biofabricated nanomaterial derived from Sansevieria trifasciata root extract, evaluating its structural, morphological, and optical properties for use in asymmetric supercapacitors. The nanomaterial comprises pristine ZnO nanoparticles (ZnO NPs) and a 1% Ag-doped ZnO nanocomposite (Ag@ZnO NC), synthesized through a green-assisted sol-gel autocombustion method. Employing techniques such as X-ray diffraction, ultraviolet-visible near-infrared, scanning electron microscopy-energy-dispersive X-rayspectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and transmission electron microscopy, the study confirms a hexagonal wurtzite structure and nanocrystallites with spherical and hexagonal shapes (30 nm). Optical analysis reveals a red shift in the band gap with Ag doping, indicating improved conductivity. The material shows potential applications in solar cells, optoelectronics, spintronics, wastewater treatment, and high-performance asymmetric supercapacitors. Raman spectra validate the wurtzite phase and identify intrinsic defects. Electrochemical tests demonstrate remarkable supercapacitive behavior with a 94% capacitance retention after 10,000 cycles, highlighting its promise as advanced asymmetric supercapacitors.

Polyalthia longifolia-mediated green synthesis of zinc oxide nanoparticles: characterization, photocatalytic and antifungal activities.

The biological synthesis of zinc oxide nanoparticles (ZnO NPs) from plant extracts has emerged as a novel method for producing NPs with great scalability and biocompatibility. The present study is focused on bio-fabricated zinc oxide nanomaterial characterization and investigation of its photocatalytic and antifungal activities. ZnO NPs were biosynthesized using the leaf extract of Polyalthia longifolia without using harmful reducing or capping chemicals, which demonstrated fungicidal activity against Fusarium oxysporum f. sp. ciceris. The results showed that the inhibition of the radial growth of F. oxysporum f. sp. ciceris was enhanced as the concentration increased from 100 ppm to 300 ppm. The effectiveness of the photocatalytic activity of biosynthesized ZnO NPs was analyzed using MB dye degradation in aqueous medium under ultraviolet (UV) radiation and natural sunlight. After four consecutive cycles, the photocatalytic degradation of MB was stable and was 84%, 83%, 83%, and 83%, respectively, during natural sunlight exposure. Under the UV sources, degradation reached 92%, 89%, 88%, and 87%, respectively, in 90 minutes. This study suggests that the ZnO NPs obtained from plant extract have outstanding photocatalytic and antifungal activities against F. oxysporum f. sp. ciceris and have the potential for application as a natural pest control agent to reduce pathogenesis.

Eco-friendly synthesis of an α-Fe2O3/rGO nanocomposite and its application in high-performance asymmetric supercapacitors.

This work presents an innovative and environmentally friendly biological synthesis approach for producing α-Fe2O3 nanoparticles (NPs) and the successful synthesis of α-Fe2O3/reduced graphene oxide (rGO) nanocomposites (NCs). This novel synthesis route utilizes freshly extracted albumin, serving as both a reducing agent and a stabilizing agent, rendering it eco-friendly, cost-effective, and sustainable. A combination of characterization techniques including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and field emission scanning electron microscopy (FE-SEM) was employed to predict and confirm the formation of the as-synthesized α-Fe2O3 NPs and α-Fe2O3/rGO NCs. Transmission electron microscopy (TEM) verified the anisotropic nature of the synthesized nanoparticles. To gain insight into the enhanced capacitance of the α-Fe2O3/rGO NCs, a series of electrochemical tests, namely cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), electrochemical impedance spectroscopy (EIS), and stability assessments, were conducted in a conventional three-electrode configuration. Furthermore, a two-electrode asymmetric supercapacitor (ASC) device was fabricated to assess the practical viability of this material. The α-Fe2O3/rGO NCs exhibited a remarkable potential window of 2 V in an aqueous electrolyte, coupled with exceptional cycling stability. Even after undergoing 10 000 cycles, the capacitive retention exceeded 100%, underlining the promising potential of this material for advanced energy storage applications.

Mycosynthesis of highly fluorescent selenium nanoparticles from Fusarium oxysporum, their antifungal activity against black fungus Aspergillus niger, and in-vivo biodistribution studies.

In the past few years, photo-luminescent inorganic materials have been studied extensively as fluorescent sensors, and diagnostic and bioimaging tools. The assessment of photoluminescence (PL) properties of selenium nanoparticles (Se NPs), especially mycosynthesized Se NPs, is still in its infancy. Herein, we have biosynthesized highly dispersed fluorescent Se NPs (42 nm) using endophytic fungus Fusarium oxysporum, and fully characterized them using sophisticated instruments like TEM, XRD, UV-Vis spectrophotometer, FTIR, and PL spectrometer. To determine the therapeutic efficacy and side effect profiles, these crystalline Se NPs were radiolabeled with technetium-99m (99mTc) and their biodistribution and renal clearance times were investigated in the normal Wister rat. The results showed that these Se NPs may be useful for targeting the lungs and liver dysfunction as significant accumulation of these NPs was observed in the liver (approx. 19.47 ± 4%) and lungs (at 6 ± 1%) after 10 min of post-injection. Quick circulation and the presence of Se NPs in kidney (3.8 ± 2%) also suggested the easy excretion of these NPs from the body through urinary tract. Furthermore, the antioxidant activity of Se NPs (IC50, 159.5 µg/mL) has been investigated using DPPH free radical scavenging assay with scavenging efficacy of 80.4% where ascorbic acid (IC50, 5.6 µg/mL) was used as a positive control. Additionally, the microscopic study of the inhibition zone encircled around Se NPs confirmed their strong antifungal and antisporulant activity against the black fungus Aspergillus niger.