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A simple approach was used to create Fe3O4-methylcellulose (MC) nanocomposites, which were then analyzed using XRD, FTIR, and FE-SEM to determine their structure. The effective factors for enhancing the ratio of magnetite NPs in the samples were investigated using RTFM and optical absorbance. Fe3O4 was synthesized utilizing the reverse co-precipitation technique and magnetic characteristics. Fe3O4/MC nanocomposites with magnetite/MC weight ratios of 0, 0.07, 0.15, and 0.25 have been developed. The diffraction pattern of magnetite is well indexed in accordance with the spinal reference pattern of Fe3O4 (space group: R¯3m), as confirmed by the Rietveld analysis of XRD data of magnetite NPs with an average crystallite size of 50 nm. Magnetite's insertion into the MC network causes a red shift in the band gap energy (Eg) as the weight percentage of magnetite nanoparticles in the samples rises. The MC, MC-7, MC-15, and MC-25 samples have Eg values of 5.51, 5.05, 2.84, and 2.20 eV, respectively. [ABSTRACT FROM AUTHOR]

Water pollution is one of the main challenges currently facing scientists around the world because of the rapid growth in industrial activities. On this basis, 2D nanolayered and nanohybrid structures, which are based on a ternary system of nickel–titanium–zinc, are considered favorable sources for designing effective nanocomposites for the photocatalytic degradation of industrial pollutants in a short period of time. These nanocomposites were designed by modifying two-dimensional nanolayers to produce a three-dimensional porous structure of multi-doped Ni/Ti-ZnO nanocomposites. Additionally, another additive was produced by constructing nanohybrids of nickel–titanium–zinc combined with a series of hydrocarbons (n-capric acid, myristic acid, stearic acid, suberic acid, and sebacic acid). Energy-dispersive X-ray spectrometry, X-ray diffraction, scanning electron microscopy, infrared spectroscopy, and thermal analyses confirmed the growth of the nanolayered and nanohybrid materials in addition to the production of nanocomposites. The positive role of the dopants (nickel and titanium) in producing an effective photocatalyst was observed through a significant narrowing of the band gap of zinc oxide to 3.05–3.10 eV. Additionally, the high photocatalytic activity of this nanocomposite enabled the complete removal of colored dye from water after 25 min of UV radiation. In conclusion, this study proposes an unconventional approach for designing new optical nanocomposites for purifying water. Additionally, it suggests a novel supporting method for designing new kinds of nanohybrids based on multi-metals and organic acids. [ABSTRACT FROM AUTHOR]

Water pollution has emerged as a major challenge for the scientific community because of the rapid expansion of the population and the industrial sector in the world. The current study focuses on introducing a new track for designing new optical nanocomposites for purifying water in addition to providing a new additive for building new nanohybrids. These targets were achieved through building a ternary system of Co/Ti/Zn nanocomposites and nanolayered structures. The Co/Ti/Zn nanolayered structures were prepared and intercalated by different kinds of organic acids: monocarboxylic and dicarboxylic acids. Long chains of organic acids were used to construct series of organic–inorganic nanohybrids. X-ray diffraction, thermal analyses, Fourier Transform Infrared spectroscopy, and scanning electron microscopy confirmed the formation of nanolayered structures and nanohybrids. The optical properties of the nanolayered structure showed that the Co/Ti/Zn LDH became photo-active compared with the usual Al/Zn LDH because of the reduction in the band gap energy from 5.3 eV to 3.3 eV. After thermal treatment, a highly photo-active nanocomposite was produced through observing more reduction for the band gap energy to become 2.8 eV. In addition, the dye of Acid Green 1 completely decomposed and converted to water and carbon dioxide during 17 min of UV radiation by the dual Co/Ti-doped zinc oxide nanocomposite. In addition, the kinetic study confirmed that the high optical activity of the dual Co/Ti-doped zinc oxide nanocomposite accelerated the degradation of the green dyes. Finally, from these results it could be concluded that designing effective nanocomposite for purification of water was accomplished through converting 2D nanolayered structures to a 3D porous structure of Ni/Ti/Zn nanocomposites. In addition, a new additive was achieved for heterostructured hybrids through building new Co/Ti/Zn/organic nanohybrids. [ABSTRACT FROM AUTHOR]

Water pollution and deficient energy are the main challenges for the scientific society across the world. In this trend, new approaches include designing zinc oxide nanohybrids to be very active in sunlight. In this line, organic and magnetic species intercalate among the nanolayers of Al/Zn to build inorganic-magnetic-organic nanohybrid structures. A series of nanolayered and nanohybrid structures have been prepared through intercalating very fine particles of cobalt iron oxide nanocomposites and long chains of organic fatty acids such as n-capric acid and stearic acid inside the nanolayered structures of Al/Zn. By thermal treatment, zinc oxide nanohybrids have been prepared and used for purifying water from colored pollutants using solar energy. The optical measurements have shown that the nanohybrid structure of zinc oxide leads to a clear reduction of band gap energy from 3.30 eV to 2.60 eV to be effective in sunlight. In this line, a complete removal of the colored pollutants (naphthol green B) was achieved after ten minutes in the presence of zinc oxide nanohybrid and sunlight. Finally, this new approach for designing photoactive nanohybrids leads to positive results for facing the energy- and water-related problems through using renewable and non-polluting energy for purifying water. [ABSTRACT FROM AUTHOR]

The plate-like structure is the most familiar morphology for conventional layered double hydroxides (LDHs) in case their structures consist of divalent and trivalent cations in their layers. In this study, nanofibers and nanoneedles of Co–Si LDHs were prepared for the first time. By the inclusion of zirconium inside the nanolayers of LDH structures, their plates were formed and transformed to nanofibers. These nanofibers were modified by the insertion of titanium to build again plate-like morphology for the LDH structure. This morphology controlling was studied and explained by a dual anions intercalation process. The optical properties of Co–Si LDHs indicated that the incorporation of zirconium within their nanolayers decreased the band gap energy from 4.4 eV to 2.9 eV. Following the same behavior, the insertion of titanium besides zirconium within the nanolayers of Co–Si LDHs caused a further reduction in the band gap energy, which became 2.85 eV. Although there is no data for the optical properties of Co–Si LDHs in the literature, it is interesting to observe the low band gap energy for Co–Si LDHs to become more suitable for optical applications. These results concluded that the reduction of the band gap energy and the formation of nanofibers introduce new optical materials for developing and designing optical nanodevices. [ABSTRACT FROM AUTHOR]

Doping processes for optical materials are one of the driving forces for developing efficient and clean technologies for decontamination of aquatic effluents through lowering their band gap energy to become effective in sunlight. The current study has used a non-conventional technique for doping zinc oxide by multi metals, non-metals and organic dyes through a one-step process. In this trend, Zn-Al nanolayered structures have been used as hosts for building host–guest interactions. Organic dyes that have inorganic species of iron, nitrogen and sulfur have been used as guests in the intercalation reactions of Zn-Al layered double hydroxides. By intercalating green dyes, organic–inorganic nanohybrids were formed as nanolayered structures with expanding interlayered spacing to 2.1 nm. By changing the concentration of green dyes and thermal treatment, series of nanofibers and nanoplates of zinc oxides were formed and doped by aluminum, iron and sulfur in addition to colored species. The optical properties of the multi-doped zinc oxide indicated that it became suitable for solar applications because its band gap energy decreased from 3.30 eV to 2.80 eV. The experimental and kinetic results of the multi-doped zinc oxide concluded that the colored pollutants were effectively removed during 50 min of sunlight irradiation. [ABSTRACT FROM AUTHOR]

Development of optical materials has attracted strong attention from scientists across the world to obtain low band gap energy and become active in field of solar energy. This challenge, which cannot be accomplished by the usual techniques, has overcome through the current study using non-conventional techniques. This study has used explosive reactions to convert non-optical alumina to series of new optical nanocomposites with very low band gap energy for the first time. In this trend, alumina nanoparticles were prepared and modified by explosive reactions using ammonium nitrate as a solid fuel. By using methanol or ethanol as a source of carbon species, three nanocomposites were produced indicating a gradual reduction of the band gap energy of alumina from 4.34 eV to 1.60 eV. These nanocomposites were obtained by modifying alumina via two different carbon species; core-shell structure and carbon nanotubes. This modification led to sharp reduction for the band gap energy to become very sensitive in sunlight. Therefore, these nanocomposites caused fast decolorization and mineralization of green dyes after illuminating in sunlight for ten minutes. Finally, it can be concluded that reduction of the band gap energy introduces new optical materials for developing optical nano-devices and solar cells. [ABSTRACT FROM AUTHOR]