Adsorption of organic pollutants, toxic metal ions, and removal of harmful bacteria can give us clean and pure drinkable water from wastewater resources. Respective magnetite nanoparticles (MNPs) were synthesized using a cheaper and greener way in an open-air environment with the use of crude latex of Jatropha curcas (JC) and leaf extract of Cinnamomum tamala (CT). Characterization of MNPs had been performed by dynamic light scattering (DLS), Ultraviolet-visible (UV-vis) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, powdered X-ray diffraction (XRD), and field emission scanning electron microscope (FE-SEM). The size ranges of the synthesized MNPs were observed in between 20–42 nm for JC-Fe₃O₄ and within 26–35 nm for CT-Fe₃O₄ by FE-SEM images. The effect of synthesized magnetic nanoparticles in wastewater treatment (bacterial portion), dye adsorption, toxic metal removal as well as antibacterial, antioxidant, and cytotoxic activities were studied. This purification will lead to an increase in the resources of pure drinking water in the future.

Herein, catalyst-free, eco-friendly, photo-triggered, self-degradation of malachite green (MG) and crystal violet (CV) dyes in comparison to photocatalytic degradation were investigated. To the best of our knowledge, this is the first systematic study to demonstrate the reactive oxygen species (ROS), electron (e⁻) and hole (h⁺) generation ability of dyes to initiate self-degradation in the presence of direct solar energy (a free source of UV radiation) and UV light (254 and 365 nm). Various experimental conditions, e.g., different dye concentrations, pH, vessel-materials (borosilicate glass and quartz) were optimized to achieve the optimum degradation outcomes. The degradation kinetics of dyes suggested the applicability of second-order-kinetics to all kinds of applied light sources. Investigation of the thermodynamic approach reveals that the self-degradation procedure was endothermic, with activation energies of 46.89 and 52.96 kJ mol⁻¹, respectively, for MG and CV. The self-degradation mechanism was further corroborated by the quantum calculations, while the formation of final degraded products for dye-degradations was established on the basis of mass spectroscopy and total organic carbon (TOC) analysis. The computed emission energies for MG and CV advocate that the excitation energy occurs due to the sole-attribution electron excitation from the Highest Occupied Molecular Orbital (HOMO) to the Lowest Unoccupied Molecular Orbital (LUMO). The close energy difference between the hydroxyl anions and the dyes also facilitates the creation of the hydroxyl radical. In a similar manner, the excited electrons from the aforementioned dyes may readily be transferred to triplet molecular oxygen, which makes it possible to generate super oxide. The radical generated in the process facilitates the self-degradation of the dyes.

Contaminated waterways, particularly effluent from the dye industry, are one of the major issues today. Among various methods adsorption is the most straightforward, effective, and successful to treat such effluents. For this purpose Copper oxide nanoparticles (CuO) and Copper oxide nanoparticles embedded within Polyvinyl alcohol (PVA) and Polyvinyl pyrrolidone (PVP) mixed polymer (CuO/PVA-PVP) were synthesized using precipitation methods and different analytical techniques such as dynamic light scattering (DLS), UV-Vis, band gap measurement, powdered X-ray diffraction(XRD), Fourier-transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) were used to characterize morphology and size. Synthesized nanomaterials were used for the adsorption of malachite green (MG) dye in aqueous solution by the batch adsorption method. Various experimental conditions e.g. contact time, concentrations, pH, were optimized to obtain the best adsorption outcome. Adsorption kinetics and isotherm suggested that it follows the pseudo-second-order kinetic and Freundlich isotherm that have maximum adsorption capacity of 40 and 76.92 mg/g for CuO and CuO/PVA-PVP, respectively. The in vitro antibacterial activity was investigated using disk diffusion and minimum inhibitory concentration (MIC) test against Staphylococcus aureus (S. aureus), a gram-positive and Escherichia coli (E. coli), a gram-negative bacteria, where both the synthesized nanoparticles showed a decent antibacterial activity against both the bacterial strain.

Phenalenyl (PLY)‐based metal complexes are a new addition to the metal complex family. Various applications of metal‐based phenalenyl complexes (metal‐PLY) have been reported, such as catalyst, quantum spin simulators, spin electronic devices, and molecular conductors, but the biological significance of metal‐PLY (metal = Co(II), Mn(III), Ni(II), Fe(III), and Al(III)) systems has yet to be explored. In this study, the anticancer properties of such complexes were investigated in ovarian cancer cells (SKOV3 and HEY A8), and the cytotoxicity was comparable to that of other platinum‐based drugs. Antibacterial activity of the metal‐PLY complexes against both gram‐negative (E. coli) and gram‐positive (S. aureus) bacteria was studied using a disk diffusion test and minimum inhibitory concentration (MIC) methods. All five metal‐PLY complexes showed significant antibacterial activity against both bacterial strains. The antioxidant properties of metal‐PLY complexes were evaluated following the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) scavenging method and were acceptable. The DNA‐binding properties of these metal‐PLY complexes were investigated using absorption spectroscopy, fluorescence spectroscopy, viscosity measurements, and thermal denaturation methods. Experimental evidence revealed that the complexes bind to DNA through intercalation, and the molecular docking study supported this conclusion.

FeSnO(OH)₅, an oxyhydroxide perovskite also known as jeanbandyite, was prepared by a co-precipitation method and investigated using XRD, SEM, TEM and UV-Vis characterization techniques. The crystal structure of the title compound adopts a cubic system of space group Pn with unit-cell parameters a = 7.6381(5) Å and V = 445.61(5) ų. The optical bandgap energy was estimated from diffuse reflectance data using a modified Kubelka–Munk function. The E_g value for the direct bandgap is 3.00 eV. The Urbach energy (E_U) was determined from the logarithmic absorption coefficient and found to be 1.256 ± 0.006 eV. The dependence of incident photon energy on optical parameters such as refractive index, extinction coefficient, real and imaginary parts of the dielectric function, real and imaginary parts of the complex conductivity, real and imaginary parts of the electrical modulus, dielectric loss and optical conductivity was investigated using UV-Vis spectrophotometer experiments. The obtained values for oscillator energy, dispersion energy, static refractive index, average oscillator strength and average oscillator wavelength were determined using the Wemple–DiDomenico model. The third-order nonlinear optical susceptibility χ⁽³⁾ and nonlinear refractive index (n₂) were calculated from linear optical parameters such as refractive index (n) and susceptibility χ⁽¹⁾.