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The sodium doped vanadium pentaoxide (Na.V 2 O 5) nanorods were synthesized through hydrothermal method. The sodium (Na) enriched V 2 O 5 nanorods with different concentration of Na varied from 1 wt%, 3 wt% and 5 wt%. X-ray diffraction, field emission scanning electron microscopy, UV–Visible spectroscopy and fourier transform infrared spectroscopy were used to investigate the structural, morphological and optical properties of the synthesized pure V 2 O 5 and Na-doped V 2 O 5 (1, 3 and 5 wt%). The microstructural studies confirmed the formation of nanorods structure for Na doped V 2 O 5. The photocatalytic performance of these synthesized photocatalysts were studied to degrade Rhodamine B dye in visible light region. Their efficiency to perform the photodegradation was improved in all Na doped V 2 O 5 samples (1, 3 and 5 wt%) than that of pure V 2 O 5 nanorods. Among all concentration of Na in V 2 O 5 nanorods, the Na.V 2 O 5 (5 wt%) exhibited the maximum degradation of the rhodamine dye having 88.9% degradation with rate constant 0.0619 min−1 of a reaction. [ABSTRACT FROM AUTHOR]

Tungsten oxide (WO3), MXene, and an WO3/MXene nanocomposite were synthesized to study their photocatalytic and biological applications. Tungsten oxide was synthesized by an easy and cost-effective hydrothermal method, and its composite with MXene was prepared through the sonication method. The synthesized tungsten oxide, MXene, and its composite were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR), energy-dispersive X-ray analysis (EDX), and Brunauer–Emmett–Teller (BET) for their structural, morphological, spectral, elemental and surface area analysis, respectively. The crystallite size of WO3 calculated from XRD was ~10 nm, the particle size of WO3 was 130 nm, and the average thickness of MXene layers was 175 nm, which was calculated from FESEM. The photocatalytic activity of as-synthesized samples was carried out for the degradation of methylene blue under solar radiation, MXene, the WO3/MXene composite, and WO3 exhibited 54%, 89%, and 99% photocatalytic degradation, respectively. WO3 showed maximal degradation ability; by adding WO3 to MXene, the degradation ability of MXene was enhanced. Studies on antibacterial activity demonstrated that these samples are good antibacterial agents against positive strains, and their antibacterial activity against negative strains depends upon their concentration. Against positive strains, the WO3/MXene composite's inhibition zone was at 7 mm, while it became 9 mm upon increasing the concentration. This study proves that WO3, MXene, and the WO3/MXene nanocomposite could be used in biological and environmental applications. [ABSTRACT FROM AUTHOR]

During the past few decades, rapid industrialization of the world communities and over use of antibiotics in the medical field have badly influenced our natural ecosystem. Now, these ever-worsening issues have succeeded in drawing the attention of the researchers. In this connection, we have fabricated binary metal substituted nickel ferrite (Ni 0.96 Cd 0.04 Gd 0.04 Fe 1.96 O 4 , NCGF) and its nanocomposite with r-GO via wet chemical method. The photocatalytic and antibacterial aptitude of the fabricated samples have been tested and compared by using organic pollutants (Methylene Blue and Rhodamine-B) and bacterial strains (Escherichia coli and Staphylococcus aureus), respectively as a representative. The nanocomposite showed better photocatalytic and antibacterial aptitude than that of pristine NCGF. More precisely, the NCGF/r-GO heterojunction based photocatalyst degraded 92.27% methylene blue (MB) dye and 53.18% Rhodamine-B (Rh–B) dye under visible light irradiation. In comparison, the NCGF photocatalyst degraded just 20.25% MB and 11.93% Rh–B dye under the same conditions. The higher activity of NCGF/r-GO photocatalyst is accredited to the suppression in the recombination process of the charge carriers caused by the addition of r-GO in the NCGF matrix. Moreover, the NCGF/r-GO photocatalyst retained 92% of its initial catalytic efficiency even after 5-recycles that indicate its higher stability and good reusability. Additionally, the NCGF/r-GO sample exhibited superior antibacterial aptitude than that of the pristine NCGF sample toward the E. coli and S. aureus bacteria. In fact, the primary constituent of the bacterial cell wall are organic compounds, lipopolysaccharide and peptidoglycan, that are also labile to degrade via photo-induced reactive oxygen species (H O • , O ‾ 2 • & H 2 O 2 ). The leakage of K+ ions from the raptured cell wall, stop the crucial cell functions that result in the death of the whole bacterial cell. This work offers new insights for the fabrication of substituted ferrites nanomaterials for environmental protection and ecological safety. [ABSTRACT FROM AUTHOR]

Co-precipitation route was used to synthesize different oxides of transition metals nano photocatalysts (Fe2O3, MnO2, Co3O4, and ZnO). The crystal structure, morphology, and elemental composition confirmation were carried out energy dispersive X-ray spectroscopy through X-ray diffraction (XRD), field emission scanning electron microscopy, and EDXS techniques. XRD analysis results revealed that the transition metal oxides are highly pure and have a very small crystallite size. It was found that iron oxide and cobalt oxide nanostructures were cubic, whereas manganese oxide, and zinc oxide nanostructures have tetragonal crystal structures. Fourier transform infrared spectra were studied to further confirm and clarify the material's structure. Surface areas of the synthesized transition metal oxides nano photocatalysts were calculated through Brunauer--Emmett--Teller isotherms. The calculated optical band gap energy for different metal oxides was between 2.02 and 2.7 eV. The nano photocatalysts were applied in the presence of aqueous methylene blue solution under visible light incandescence in order to set up the ascendancy of heterogeneous photocatalysis. It is observed that the photocatalytic efficiency of the oxides of transition metals simply depends upon the particle size of the nano-sized material and its surface area. It is concluded that iron oxide nano-photocatalyst reveals the best photocatalytic efficiency because of the high surface/charge ratio and variation in surface orientations. It is suggested that nano-sized iron oxides (Fe2O3) is a propitious candidate to resolve environmental issues related to the poisonous ecosystem because it has a great potentiality in heterogeneous photo disintegration and can establish a better green environment. [ABSTRACT FROM AUTHOR]

A multipurpose, environment-friendly, and effective catalyst for control of environmental contaminants is an enduring interest in recent years. In the present study, lanthanum substituted spinel ferrite (La x MnFe 2-x O 4) nanoparticles were synthesized using an eco-friendly, low cost-effective reverse-micelle synthesis strategy. Thermal analysis was done to annualize the annealing temperature of prepared precipitates. X-ray diffraction (XRD) study revealed the well-defined cubic spinel structure of La x MnFe 2-x O 4 with the presence of a very minute secondary phase by the introduction of La3+ ion. Fourier transform infrared spectroscopy (FTIR) study confirmed the M − O metal-oxygen bond stretching at tetrahedral and octahedral sites. Surface morphology analyzed by field emission scanning electron microscopy (FESEM) revealed the narrow size distribution having nanoparticles size of nearly 60 nm. From the bandgap study, an enhanced redshift of 2.40 eV directed its semiconductor photocatalysis behavior. The degradation efficiency of pristine MnFe 2 O 4 and La3+ ion substituted MnFe 2 O 4 material was investigated using a contaminant crystal violet dye. Higher degradation efficiency, kinetic investigation smart degradation mechanism, and simple recovery suggested that the newly designed La3+ ion substituted MnFe 2 O 4 photocatalytic material is best for environmental remediation. [ABSTRACT FROM AUTHOR]

Cu 0.2 Ni 0.8 O nano-particles and their nano-hybrids were synthesized by wet chemical methods and examined by X-ray diffraction (XRD) technique, spectroscopic analysis, Field Emission scanning electron microscopic (FESEM) technique and energy dispersive x-rays (EDX) analysis. XRD results confirmed that the synthesized materials were crystallite in the cubic phase of Cu 0.2 Ni 0.8 O nano-particles annealed at 500 and 800 °C. The crystallite size synthesized product was found to be around 5–20 nm. FTIR and EDX results were supporting XRD data. Morphological studies represented the spherical nature of Cu 0.2 Ni 0.8 O nano-particles annealed at 500 and 800 °C with particle size <70 nm. Electrochemical measurements of Cu 0.2 Ni 0.8 O nano-particles annealed at 500 and 800 °C and their nano-hybrids were also performed. Brilliant specific capacitance (303 F g-1) was observed in the case of rGO-based nano-hybrid of Cu 0.2 Ni 0.8 O nano-particles annealed at 500 °C. This additional noted specific capacitance was credited to more conducting nature and relatively high surface area of graphene. [ABSTRACT FROM AUTHOR]

Unsubstituted NiO and its derivatives with Cu +2 and Zn +2 were synthesized by co-precipitation method. Structural characterizations were done by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopic and scanning electron microscopic (SEM) techniques. XRD results confirmed the cubic phase of NiO and all its derivatives. The crystallite size for all compositions of NiO nanoparticles was found 10–20 nm. XRD data was also used to calculate other physical parameters like lattice constant, unit cell volume, micro-strain, dislocation density, X-rays density and porosity. It was found that the synthesized nanomaterials have single phase. XRD data was supported by FTIR results. Morphological studies confirmed the spherical nature of NiO particles with size <100 nm. Optical characterization was done by UV–Visible spectroscopic technique. The indirect band gap energy of NiO was ∼3.42 eV and band gap tuning was noticed in the case of transition metal cations substitution. Zn+2 substituted NiO nano-crystallites exhibited lowest band gap energy (3.06 eV). The nanoparticles with lower band gap may have better photocatalytic and other related properties. DC electrical properties were recorded by two probe technique. An increase in electrical conductivity was noticed as a result of divalent transition metal cations substitution. Cu +2 substituted NiO exhibited highest conductivity due to more conductive inherent nature of copper. Thus the Dc conductivity values for various compositions of NiO nanoparticles were observed in range 4.39 × 10-10 to 4.50 × 10-8 Scm-1. [ABSTRACT FROM AUTHOR]

Abstract: New type of aromatic–aliphatic polyamide/montmorillonite nanocomposites were produced using solution intercalation technique in dimethylacetamide. The modification of clay was carried out with ammonium salt of long chain alkyl amine. The nanocomposites were probed for organoclay dispersion, mechanical, thermal and water absorption measurements. Formation of delaminated and intercalated nanostructures was confirmed by X-ray diffraction and TEM studies. Improvement in tensile strength and modulus was observed for nanocomposites with optimum organoclay content (8-wt.%). Thermogravimetric analysis indicated an increase in thermal stability of nanocomposites as compared to pristine polyamide. Differential scanning calorimetric results revealed increase in glass transition temperatures (T g ) with augmenting organoclay in the nanocomposites. Water uptake of the nanocomposites reduced than the neat polyamide rendering decreased permeability. [Copyright &y& Elsevier]

A facile strategy was used for the synthesis of nickel ferrite/zinc oxide (NiFe 2 O 4/ ZnO) nanocomposite via an ultra-sonication method and observed its recyclability and photostability with enhanced visible light-driven photocatalytic performance. The photo degradation activities of as-synthesized photocatalysts were investigated using various dyes including methylene blue, crystal violet and methyl orange under solar light irradiation. Prepared material degrades 49.2% methyl orange, 44.4% methyl blue and 41.3% crystal violet in 40 min. Further, the synergistic effect of nickel ferrite and zinc oxide can reduce the probability of recombination of charge carrier and boost the charge separation which leads to remarkable photocatalytic performance. Magnetic properties of nickel ferrite reduces the agglomeration of material and increases the recyclability. The NiFe 2 O 4/ ZnO nanocomposites also exhibited better antibacterial activity for Pseudomonas aeruginosa and Staphylococcus aureus , which shows that they can be used for both environmental and biological applications. [ABSTRACT FROM AUTHOR]

2D material-based Bi 2 O 3 /MXene nanohybrids were successfully fabricated through an ultrasonication method. MXene (Ti 3 C 2 Tx) nanosheets were prepared via simple H.F. etching while bismuth oxide nanoflowers were prepared by the co-precipitation method. The structure, morphologies, and optical properties of all the prepared samples were analyzed by various advance techniques such as X-ray diffraction (XRD), UV–Visible spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). To check the photocatalytic efficiency of prepared material was performed for both colored and colorless dyes. A significant increase in photocatalytic properties were observed for methylene blue and benzoic acid. The prepared nanohybrid showed 1.6 folds higher efficiency than bismuth oxide nanopetals. The relatively higher utilization efficiency of sunlight and the rapid separation rate of photogenerated electron and hole pairs helped to enhance the photocatalytic performance synergistically. Additionally, the antibacterial activity of all samples was also carried out using the disc diffusion method against K. pneumonia and S. aureus. Improved properties could be attributed to an increase in d-spacing of 2D MXene layers by inserting nanopetals which reduced the restacking of MXene layers. Furthermore, multiple functional groups on the surface of MXene will also play an important role in enhancing the properties of its nanohybrids. We expect that the as-synthesized nanohybrid will attract researchers' attentions for the degradation of industrial pollutants. [ABSTRACT FROM AUTHOR]

DyCr x Fe (1-x) O 3 (0 ≤ x ≥ 0.4) nanoparticles were prepared using facile chemical route. Structural and morphological evaluation was carried out using X-ray diffraction (XRD) and electron microscopy. Formation of orthorhombic DyFeO 3 nanoparticles was confirmed by XRD with crystallite size of 9–10 nm. FESEM images revealed nearly spherical morphology of the fabricated nanoparticles. Energy dispersive X-ray (EDX) technique was employed to confirm the presence of Dy, Cr, Fe and O elements in DyCr x Fe (1-x) O 3 nanoparticles. FTIR studies illustrated the presence of characteristics stretching and bending vibrations. UV–visible spectroscopy was used to analyze the photocatalytic performance of the DyFeO 3 and Cr-substituted DyFeO 3 nanoparticles and optical band gap measurements. Photocatalytic activities of the prepared substituted and un-substituted DyFeO 3 nanoparticles were conducted using three different dyes. These dyes were (i) methyl orange, (ii) rhodamine B and (iii) methylene blue. Lower band gap and higher photocatalytic performance was observed for Cr-substituted DyFeO 3 nanoparticles with methylene blue dye. [ABSTRACT FROM AUTHOR]

• NiFe 2 O 4 was successfully synthesized via co-precipitation route. • Various physio-chemical techniques were employed to characterize the prepared samples. • The prepared photocatalysts were used for the degradation of pendimethalin under sunlight. • rGO based nanocomposite showed maximum degradation efficiency. • Gd doping and insertion of rGO sheets help to enhance the photo-degradation ability of nickel ferrite. NiFe 2 O 4 (F-1) and rare earth metal (Gd) doped NiFe 2 O 4 (F-2) were prepared via a co-precipitation approach. Gd-NiFe 2 O 4 @rGO (F-3) was prepared via an ultrasonication route for the degradation of pendimethalin under sunlight. The structural confirmation of as-fabricated samples was done via XRD. The Tauc plot of F-1 showed a bandgap energy of 2.79 eV and F-2 exhibited a bandgap energy of 2.63 eV. The optical band gap was lowered due to the presence of rare-earth metal ions. NiFe 2 O 4 and Gd-NiFe 2 O 4 showed 48.88 %, and 61.11 % degradation of pendimethalin. Gd-NiFe 2 O 4 @rGO nanocomposite showed the highest degradation efficiency. It exhibited 84.44 % degradation of pendimethalin in 140 min at the rate of 0.01 min−1. The reason for the greater activity is due to the insertion of rare earth (Gd) ions and rGO sheets in the nickel ferrite. The doping with rare earth metal ions lowers the recombination of electrons and holes which was further supported by the addition of carbonaceous material. The surface area of the nickel ferrite was improved by rGO sheets and in turn more active sites were formed on the surface of the catalyst which fastens the rate of reaction. [ABSTRACT FROM AUTHOR]

Transition metal spinel type mixed oxides (FeCo 2 O 4 , MnCo 2 O 4 and ZnCo 2 O 4) nano-catalysts have been synthesized via co-precipitation route. The samples were characterized using XRD and FE-SEM techniques to determine structure and morphologies respectively. Furthermore, FTIR and BET analysis were carried out in order to confirm the structure and calculate surface areas of the samples. The photocatalytic potency of synthesized nano-catalysts have been examined for aqueous solution of methylene blue under visible light. It is found that photocatalytic activity of simple transition metal oxides was enhanced by making their binary/ternary metal oxides. FeCo 2 O 4 exhibited highest photocatalytic efficiency among the prepared spinel structures while MnCo 2 O 4 possess lowest efficiency. The photocatalytic behavior of mixed transition metal oxides can be accredited to its spinel structure, small particle size and large surface area. XRD and BET results revealed the small crystallite and particle size of spinel mixed oxides. The small crystallite size of spinel mixed oxides nano-structures contributes to increased photocatalytic activity by increasing the surface area of photocatalyst, decreasing the chance of reunion of charge carriers. It is observed that these binary oxide nano-structures have potential applications in heterogeneous photo decay of environmental contaminants and can act as propitious materials for resolving environmental issues and establishing green environment. • Spine oxide nano-catalysts were prepared via facile route. • Crystallite size was found < 10 nm. • All prepared nano-catalysts exhibited good photocatalytic activity. [ABSTRACT FROM AUTHOR]