Copper-doped TiO₂ nanoparticles were synthesised using an ultrasonic-assisted sol–gel method with various doping concentrations from 0 to 2.5 at.%. The samples were characterised by X-ray diffraction, UV–vis diffuse reflectance spectroscopy (UV–vis), transmission electron microscopy (TEM), Brunauer–Emmett–Teller surface area determination, and zeta potential. The presence of copper in TiO₂ crystal structure was revealed by UV–vis spectra, and the TEM analysis showed that particles are mainly spherical around the size range of 15–20 nm. In addition, doping copper into TiO₂ lattice caused a decrease in the surface area due to the aggregation of nanoparticles and a shift of isoelectric point towards lower pH when the dopant concentration increased. The photocatalytic reactivity of these materials was evaluated by the degradation of methylene blue and methyl orange under the UV light. The effect of the initial solution pH on the adsorption capacity and the photocatalytic behaviour of the Cu-doped TiO₂ in the decolourisation of these dyes were also studied.

This article describes the synthesis of curcumin complexes with metal ions. Properties of these complexes such as spectra IR and UV-Vis and solubility were investigated. The optimum parameters of ultrasound to enhance the solubility was figured out as follows: the capacity of ultrasound: 750 W/g; the time of ultrasound: 7 min; the concentration of the surfactant Tween 80 : 2%. The maximum solubility (mg/ml) of complexes was as follows: Cur-Fe(III): 0.162 ± 0.01; Cur-Zn(II): 0.267 ± 0.02; and Cur-Ca(II): 0.417 ± 0.05. Antioxidant capacity (DPPH, %I) of curcumin complexes was higher than that of curcumin-free complexes. All of these curcumin complexes revealed antimicrobial activities, in which calcium complex had the best resistance against Salmonella, followed by Fe(III) complexes. Meanwhile, the zinc complex was not resistant to this bacterium. These complexes showed antibacterial activity on Staphylococcus aureus, in which Cur-Ca (II) complexes had the highest antibacterial activity. For Escherichia coli, the Cur-Zn (II) complex had no resistance, while the Cur-Ca (II) complex showed the highest antibacterial activity.

A novel Mn ₃ O ₄ /ZnO nanocomposite supported on microalgae-derived activated carbon demonstrated excellent photocatalytic efficiency, reusability, and safety for rhodamine B wastewater treatment.

In this research, nanostructured magnesium oxide was synthesized through the sol-gel calcination or hydrothermal calcination method using various surfactants. The X-ray diffraction pattern of the materials confirmed that all the prepared magnesium oxide samples were single phase without any impurity. The scanning electron microscopy images and specific surface area values showed that sodium dodecyl sulfate was the most suitable surfactant for the synthesis of magnesium oxide nanoplates with the diameter of 40–60 nm, the average thickness of 5 nm, and a specific surface area of 126 m²/g. This material was utilized for nitrogen dioxide and sulfur dioxide adsorption under ambient condition. The saturated adsorption capacities of magnesium oxide were 174 mg/g for nitrogen dioxide and 160 mg/g for sulfur dioxide, making the magnesium oxide nanoplates a promising candidate for toxic gas treatment.

This paper describes a new technique to enhance the solubility of metal curcumin complexes. The solubility of the complex has increased significantly by the homogenization technique with the assistance of surfactants. The optimum conditions of the method have been determined, such as time, temperature, and surfactant concentration. The antioxidant, antibacterial, and anti-inflammatory activities of these complexes have been studied. The results show that the curcumin complexes have promising potential in antibacterial, antioxidant, and in the treatment of restoring burns in rats. The wounds of rats, treated by using 0.2 mg mL⁻¹ of curcumin and its complex solutions three times daily, have wholly recovered after 12, 15, and 18 days of treatment with curcumin–Ca(II), curcumin–Zn(II), and curcumin–Fe(III), respectively.