Iron oxide nanoparticles (IONPs) are highly effective and environmentally sustainable adsorbents for the removal of heavy metals from wastewater. This study focuses on exploring a green route for synthesizing IONPs using Hibiscus rosa-sinensis petal extract, promoting an eco-friendly approach. The synthesized particles were evaluated analytically using XRD, confirming a crystallite size of 6.16 nm, and were assessed for adsorption of Pb(II) and Cu(II) ions. Optimized adsorption conditions, including pH 5 and an interaction period of 30 minutes, resulted in high removal efficiencies of 95.48% for Pb(II) and 84.9% for Cu(II). Adsorption behavior was best explained by the Langmuir isotherm, revealing maximum adsorption capacities of 30.77 mg/g and 28.74 mg/g for Pb(II) and Cu(II) respectively, while kinetic studies confirmed a pseudo-second-order model. These findings underscore the potency of green-synthesized IONPs as a promising and sustainable solution for wastewater treatment, paving the way for their potential real-world applications.

Nanotechnology has been a constant subject of innovation in the past two decades. Novel innovations have been carried out to enhance the properties of nanoparticles, especially by doping. It is one of the main ways to augment the properties of a semiconductor. In the present paper, alkali (Na/K) doped cobalt ferrite nanoparticles (NPs) were successfully synthesized and investigated for their effectiveness for photocatalytic degradation of Methylene Blue (MB) and Methyl Orange (MO), as well as antioxidant properties. So obtained Na/K doped CoFe₂O₄ were characterised for the evaluation of their structural, elemental, morphological, and optical criteria via using standard characterisation methods like XRD, SEM, EDX, TEM, and UV-Visible spectroscopy. The XRD results showed the crystallite size of Na-doped CoFe₂O₄ to be between 25 to 26 nm, while that for K-doped it was between 15 to 16 nm. The smaller crystallite size of K-doped particles can be attributed to the fact that K has a larger ionic radius than Na and causes more lattice strain, disrupting the lattice growth. The morphological variations with the dopants and elemental composition have been confirmed by using SEM-EDS and TEM results. The UV-Visible results implied the absorption regions for Na/ CoFe₂O₄ with band gap energy between 1.65 to 1.5 eV, while for K/CoFe₂O₄ it is between 1 to 1.41 eV. Based on the results, it was established that K/CoFe₂O₄ exhibited greater photocatalytic and antioxidant properties.

Zirconia nanoparticles (ZrO₂ NPs) are eco-friendly and biocompatible materials used for various biological applications. Herein, we reported Terminalia catappa (T. catappa) fallen leaves extract encapsulated ZrO₂ NPs without using a chemical reducing agent. The bandgap, absorption, functional groups, and crystalline structure were identified using a UV-Visible spectrophotometer (UV-Vis), a Fourier transform infrared spectrometer (FT-IR), and an X-ray diffractometer. The transmission electron microscope (TEM) images confirmed the formation of spherical particles with an average size of 6 nm. The absorption in the range of 299-307 nm confirmed the formation of ZrO₂ NPs. The stretching vibration bands at 467 and 621 cm⁻¹ confirmed the presence of the Zr-O-Zr bond in ZrO₂ NPs. According to the X-ray diffraction pattern (XRD), the average crystallite size of the ZrO₂ NPs was 4 nm with a cubic structure. The nanoparticles Zr0.01, Zr0.02, and Zr0.03 exhibited 26, 28, and 32 mm zones of inhibition against Lactobacillus acidophilus, Staphylococcus albus, and Streptococcus mutans at a maximum concentration of 25µg/ml. The ZrO₂ exhibited an IC₅₀ value of ZrO₂ to be 32.63 μg/mL against A549 cell lines. Therefore, biogenic T. catappa extract-encapsulated zirconia nanoparticles can be used for the development of potential antibacterial and anticancer agents.

The catalytic liquid-phase Beckmann rearrangement of cyclohexanone oxime to ε-caprolactam has been effectively achieved using ZSM-5 nanoparticles as catalysts. Comprehensive characterization of the catalysts was performed by utilizing techniques such as DLS, XRD, FT-IR, N₂ adsorption–desorption isotherms and NMR analysis. A systematic investigation of key reaction parameters, including the concentration of cyclohexanone oxime, catalyst loading, reaction temperature, and catalyst reusability, was conducted to optimize the catalytic process. The results demonstrate that the ZSM-5 nanoparticles aged at 80°C for 24 h and calcined at 550°C for 5 h (denoted as ZSM-5(50)-24/c) exhibited superior catalytic performance, achieving the highest conversion of cyclohexanone oxime and exceptional selectivity for ε-caprolactam under optimized conditions. The optimum reaction conditions are 0.10 g of ZSM-5(50)-24/c catalyst, cyclohexanone oxime concentration of 100 mmol and the reaction temperature of 120°C. This catalytic system offers notable advantages, including environmental sustainability, straightforward separation, and efficient catalyst recovery and recyclability. These features make it a promising approach for industrial applications in ε-caprolactam production, aligning with the green chemistry principle.

Reactive oxygen species (ROS), are highly reactive molecules formed as a natural by-product during cellular metabolism primarily within the mitochondrial matrix. Excessive production of ROS may cause serious illnesses like cardiovascular disease, diabetes, cancer, Alzheimer's and Parkinson's disease. The therapeutic drugs currently available in the market for the treatment of these illnesses have larger systemic effects and a variety of adverse effects. Therefore, it is important to identify an alternative way of delivering drugs in the form of nanomedicine, which has low cost, great efficacy, fewer side effects, and narrower systemic effects. Nanoparticles have the potential to deliver drugs at specific targeted sites and can be used as new therapy methods for the treatment of various diseases and can also be used in diagnostic methods. This review paper aims to examine the synthesis of nanomedicine, its delivery methods within the body and its mechanism of action against ROS-induced diseases. The findings of our study suggest that nanomedicine-based therapy may be a very effective method in the treatment of cancer, diabetes mellitus, cardiovascular diseases, Alzheimer's and Parkinson's disease. However, nanomedicine raises a variety of safety concerns, including the risk of toxicity and persistence in the tissues of humans.