Morphological influence of BiVO4 nanostructures on peroxymonosulfate activation for highly efficient catalytic degradation of rhodamine B

Bismuth vanadate (BiVO₄) nanostructured films were prepared and successfully applied for peroxymonosulfate (PMS) activation for the degradation of rhodamine B (RhB) in aqueous solution. The BiVO₄ thin films were obtained by thermal reaction between electrodeposited bismuth (Bi) films and vanadium precursor. The as-prepared BiVO₄ porous, nanoflowers, and cluster nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and BET analysis. The catalytic performance of BiVO₄ nanostructures has been carefully evaluated in activating PMS for the degradation of RhB. The nanoflower-like BiVO₄ nanostructures exhibit the best catalytic activity. Under optimized conditions, the complete catalytic degradation of RhB using BiVO₄ nanoflowers/PMS system was achieved in 17 min at room temperature as revealed by high-performance liquid chromatography (HPLC) analysis. Quenching experiments suggested that sulfate radicals are the main active species in the degradation process. Additionally, BiVO₄ catalyst remained stable without any apparent activity loss after five cycling runs.

Regulation of Mitochondrial and Cytosol Antioxidant Systems of Fenugreek (Trigonella foenum graecum L.) Exposed to Nanosized Titanium Dioxide

In the present study, the interactions between nanoparticle (NP) exposure, root application and plants were examined. NPs are potentially responsible for conformational changes in polysaccharides, lipids, proteins, pectin, suberin and lignin molecules. 4 days of treatment with metal oxide caused a statistically significant increase in nicotinamide adénine dinucléotide oxidase activity in mitochondria and cytosol. Following exposure to TiO₂NP, even lipid peroxidation levels decreased in the mitochondria (leaves, stem and root) and in the cytosol (leaves and root), although it increased in the cytosol of the stem. Malondialdehyde accumulation was found to be higher in the cytosol compared to the mitochondria of stems, and in the cytosol of leaves and roots. NPs caused alterations in metabolism, antioxidant enzyme activities (guaiacol peroxidase, catalase and ascorbate peroxidase) and the generation of oxidative stress. Effects caused by exposures to NPs were influenced by differences in metabolic responses in plant parts, plant compartments, the period of exposure and the NP doses.