CeO2/CdO multi-layered nanoplatelet arrays have been synthesized by sol–gel method at two different temperatures using Citrus limonum fruit extract and the effect of particle size on the ...photocatalytic performance is studied. The particle size and phases was analysed by X-ray diffraction pattern (XRD) which brought out the formation of cubic phase in the synthesized samples. Field Emission Scanning electron microscopy (FESEM) revealed the surface morphology and made up of cumulative form of platelet shaped arrays with an average size of 10nm. The elemental composition and the purity of the nanomaterials were confirmed by Energy Dispersive X-ray spectroscopy (EDX). CeO2/CdO multilayered binary metal oxide nanoplatelet arrays were formed which was further explored with Fourier transform infrared spectroscopy (FTIR), it reveals that the nanocomposites contain CeO and CdO bonds. Determination of the direct and indirect bandgap energy of the nanoplatelet arrays was carried out by UV–Vis-DRS studies. In MG degradation, both the hole (h+) and hydroxyl radical (OH) played a major role than the superoxide radical (O2−). Possible photo degradation mechanisms are proposed and discussed in this article. CeO2/CdO multi-layered nanoplatelet arrays showed antibacterial activity and among the tested ones, it showed better growth inhibition towards P. aeruginosa MTCC73. Thus, this greener synthetic procedure was a highly effective method due to low-cost, highly effective UV light responsive material for environmental safety.
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•(h+) & (OH) played a major role than the superoxide radical (O2−).•Cumulative form of platelet shaped arrays with an average size of 10nm•Limonum fruit extract the effect of particle size on the photocatalytic performance.•Greener synthesis was highly effective method.•Exhibit showed better growth inhibition towards P. aeruginosa MTCC73.
The ZnO thin films have been prepared by spin coating followed by annealing at different temperatures like 300°C, 350°C, 400°C, 450°C, 500°C & 550°C and ZnO nanoparticles have been used for ...photocatalytic and antibacterial applications. The morphological investigation and phase analysis of synthesized thin films well characterized by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Photoluminescence (PL), Transmission Electron Microscopy (TEM) and Raman studies. The luminescence peaks detected in the noticeable region between 350nm to 550nm for all synthesized nanosamples are associated to the existence of defects of oxygen sites. The luminescence emission bands are observed at 487nm (blue emission), and 530nm (green emission) at the RT. It is observed that there are no modification positions of PL peaks in all ZnO nanoparticles. In the current attempt, the synthesized ZnO particles have been used photocatalytic and antibacterial applications. The antibacterial activity of characterized samples was regulated using different concentrations of synthesized ZnO particles (100μg/ml, 200μg/ml, 300μg/ml, 400μg/ml, 500μg/ml and 600μg/ml) against gram positive and gram negative bacteria (S. pnemoniae, S. aureus, E. coli and E. hermannii) using agar well diffusion assay. The increase in concentration, decrease in zone of inhibition. The prepared ZnO morphologies showed photocatalytic activity under the sunlight enhancing the degradation rate of Rhodamine-B (RhB), which is one of the common water pollutant released by textile and paper industries.
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•The effect of RhB dye particle on the photocatalytic performance•(h+) & (•OH) played a major role than the superoxide radical (O2•−).•Photocatalytic activity under the sunlight enhancing the degradation rate•Antibacterial activity of characterized was regulated using different concentrations.•ZnO thin films were deposited on the silicon substrate by the sol-gel technique.
Ceria (CeO2) is an exciting alternative noble metal catalyst, because it has ability to release and absorb oxygen in the redox system, and function as an oxygen buffer. In this study, ...heterostructured catalysts consisting of CeO2/Y2O3 nanocomposites were successfully synthesized by hydrothermal method in the presence of sodium hydroxide as a reducing agent from cerium nitrate and yttrium nitrate as a precursor which was then evaluated for its photocatalytic activity in the degradation of Rhodamine B (RhB) synthetic dye. Scanning electron microscopy (SEM) imparts the surface morphology and size of the prepared sample. Elemental compositions and the purity of the nanoparticles are proved by energy dispersive X-ray Spectroscopy (EDX). CeO2/Y2O3 nanoparticles were made up of CeO and YO bonds which are confirmed by Fourier transform infrared spectroscopy (FTIR). Synthesis temperature and pressure, during hydrothermal reactions, plays a critical role in controlling the shape, size, oxygen vacancy concentration, and low temperature reducibility in CeO2 based nanocomposites. The lattice constants and oxygen vacancy concentrations of ceria nanoparticles also depend upon the concentration of hydroxide ion which leads to better morphology at low temperature and pressure. Hydrogenation of p-nitrophenol to p-aminophenol with a reducing agent is conveniently carried out in aqueous medium by using this binary metal oxide catalyst. Further, the photocatalytic performance of the synthesized nanoparticles was monitored by photocatalytic degradation of Rhodamine B synthetic dye under UV light irradiation. To get maximum photocatalytic degradation (PCD) efficiency, we have used H2O2 for the generation of excess reactive oxygen species (ROS). In addition, the antibacterial activity of nanoparticles against bacteria was also examined. The observed antibacterial activity results are comparable with the results obtained using the standard antibiotic.
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•CeO2/Y2O3 nanocomposites were successfully synthesized by hydrothermal method.•H2O2 for the generation of excess reactive oxygen species (ROS)•Hydrogenation of p-nitrophenol to p-aminophenol with a reducing agent•Specifically lattice planes associated with cubic CeO2 can be observed with SAED.•Observed antibacterial results are comparable with the standard antibiotic activity.
Cerium (IV) oxide (CeO2) is the most accessible noble rare earth metal oxide for the excitation of the excitons by light-harvesting performance. The present work is focused on Erbium doped ceria ...nanoparticles that were beneficially obtained by hydrothermal method from cerium nitrate and Erbium nitrate as precursors for decomposition of Rhodamine-B (RhB) dye in the polluted waste water removed from the industries. Dye removal efficiency of the catalyst was found to be nearly ~94%. The structural phases, functional groups and the transitions are identified with the help of various techniques. XRD pattern determines the development of cubic phase with the particle size is 20 nm. Highly crystalline nature of as-synthesized nanomaterials with an average diameter of 35 nm was investigated by HRSEM. The crystalline size, shape and textural morphology, of the Erbium doped ceria nanostructures were analysed by HRTEM. Our results suggest, that the concentration of OH– ion determines the lattice constants and oxygen vacancy in the nanostructures which stimulate the probability of photocatalytic decomposition effect of organic pollutants, due to synergistic approach. In this context, both unhydrolyzed things and their swiftly drip from deceased or scratched cells with conceded membranes, even when the cells embrace some are outstanding attention. Although, the loss of viable cells also depends on epithelial cell dynamically conceal of numerous molar matrix.
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•Dye removal efficiency of the catalyst was found to be nearly 94%.•The development of cubic phase with the particle size is 20 nm.•Ce3+ and Ce4+ ions in ceria with their high oxygen mobility.•When the smaller size Er3+ ion is replaced the cerium ion in ceria matrix•490 cm−1 due to the presence of metal-oxide bond (CeO)
Cobalt Molybdate (β-CoMoO4) and Cobalt Oxide (Co3O4) nanocomposite was prepared via co-precipitation and solid-state methods. Various techniques like powder XRD, FESEM, HRTEM, FTIR, VSM, UV–Vis and ...PL spectroscopy were used to investigate the structure and morphology of as prepared samples. Powder X-ray diffraction (XRD) reveals monoclinic and cubic structure for β-CoMoO4 and Co3O4 respectively. The surface morphology was observed using field emission electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM), which shows the formation of nanocomposites at nanoscale range, the presence of elements were determined by energy dispersive x-ray spectroscopy (EDX). FTIR analysis confirms the formation and bonding nature of the samples. The anti-ferromagnetic behavior of CMCO64 composite was determined by vibrating sample magnetometer (VSM). The bandgap values were calculated by extrapolating the straight line on the energy axis (hν), and the values of β-CoMoO4, CO3O4 and β-CoMoO4 - CO3O4 composites were determined to be 2.20, 2.09 eV and 1.54–2.44 eV respectively. The weak blue emission peak observed at 489 nm is corresponds to crystal defects only observed in CMCO01 and CMCO64 composite, for CMCO10 the peak shifted to green region. Antibacterial studies illustrate good result for the CMCO64 composite against both Gram-negative and Gram-positive bacteria. The sensor studies were measured at different humidity environment (RH5% to RH98%). It was found that the increase in relative humidity leads to increase in the sensitivity factor of the samples. Among the samples CMCO64 composite possess highest sensitivity factor of (Sf = 4851) with response time of 60 s and recovery time of 230 s respectively.
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•Combination of Ferro and antiferromagnetic behaviour•Exhibits broad green and red emission peaks•Nanorod structure for β-CoMoO4 and sphere like structure for Co3O4•Shows highest sensitivity factor of Sf = 4851•Promising antibacterial activity against both Gram-negative and Gram-positive bacteria
MgO decked few layer Graphene Coated Fullers' Earth (MgO-FLG-FE) is prepared by microwave irradiation and tested as adsorbent to remove Acid Blue 9 (AB9) and Safranin O (SO) dye from aqueous ...solutions. MgO-FLG-FE was characterized by FTIR, XRD, FESEM, HRTEM, RAMAN, and BET. The adsorbent dose required for the maximum removal of AB9 and SO dyes are 1.0 g and 0.08 g which is in very low quantity compared with FE. The contact time to achieve equilibrium is 120 min in both the dyes. Langmuir, Freundlich and Dubinin-Radushkevich adsorption isotherms are applied to understand the adsorption mechanism for both the dyes in aqueous solutions. The uptake of AB9 and SO dye by MgO-FLG-FE is best explained by Langmuir adsorption isotherm. The adsorption capacities of MgO-FLG-FE for AB9 and SO are 37.7 mg/g and 201.1 mg/g respectively when compared with Fuller's Earth (36.7 mg/g and 131.19 mg/g). The adsorbent capacity of FE was enhanced by coating with very small amount of MgO decked FLG. The Pseudo-second order equation is best explained through the adsorption kinetics in this study.
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•Novelty of decorating MgO-decked FLG on Fuller's Earth.•Understanding morphological features of MgO-FLG-FE is also interesting.•FEA capacity is increased by decorating with MgO-decked few layer graphene.•MgO-FLG-FE acts as an excellent adsorbent to remove Safranin O & Acid blue 9 dyes.•Chemisorption is the major mode of adsorption of SO and AB9 dyes onto MgO-FLG-FE.
In the present study, we describe an effective synthetic strategy of pure and heterostructured CeO2/Y2O3 binary metal oxide nanostructures in distinct molar ratios (1:1; 1:2 & 2:1) in which sodium ...hydroxide act as a reducing agent under chemical precipitation assisted hydrothermal method (CPHM). Controlled shape and size of CeO2/Y2O3 hierarchical nanostructures was achieved by using cerium nitrate and yttrium nitrate as a precursor. Synthesized nanostructure was fully analyzed by various techniques to detect its crystalline nature such as size, morphology; purity & optical activity is followed by the evaluation of its photocatalytic activity in the degradation of RhB dye. The crystalline structure was examined by X-ray diffraction (XRD), shows the cubic phase for both metal oxides in synthesized systems and found to be an efficient catalyst to generate reactive oxygen species (ROS) in presence of UV/Visible light, which tends to degrade various polyaromatic organic dyes into small fractions. Among all the heterostructured CeO2/Y2O3 binary metal oxide nanostructures the Ce2/Y1 sample shows the formation of hierarchical nanorods with particle diameter in the range of 8–50 nm. Due to their hierarchical one-dimensional nanostructures and increased surface areas, the CeO2/Y2O3 hierarchical nanorods exhibit substantially higher photocatalytic performance than the pure CeO2 and other mixed nanostructures in the degradation of RhB synthetic dye.
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•CeO2/Y2O3 nanocomposites were successfully synthesized by hydrothermal method.•H2O2 for the generation of excess reactive oxygen species (ROS).•Which tends to degrade various polyaromatic organic dyes into small fractions.•Major chromophoric groups like CO, CN, CC, NO2, NN.•To exploit extensive spectrum of driven sunlight and visible light irradiation.
A low energy bandgap between Ce3+ and Ce4+ states in cerium oxides, high oxygen mobility and high oxygen storage capacity are the properties that qualify them to be the most widely used heterogeneous ...catalysts. This present work is an account of studies that were carried out on the synthesis and catalytic properties of pure CeO2, CeO2/La2O3 based binary metal oxide nanostructures prepared by the hydrothermal method. Our results revealed that the synthesis temperature and pressure during hydrothermal reactions played a critical role in controlling the shape, size, oxygen vacancy, and low temperature reducibility in CeO2 based nanostructures. In addition, OH− ion concentration was found to play an important role in engineering the lattice constants and oxygen vacancy defects. The present report demonstrated that the hydrothermal synthesis is a facile one step approach for the preparation of compositionally homogeneous cerium based binary metal oxide nanostructures, in which CeO2/La2O3 mixed oxides have a superior low-temperature oxygen release capability compared to pure CeO2. We have also demonstrated that the nanomaterials are proved to have higher catalytic performance at low temperatures as compared to pure ceria nanoparticles.
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•Bandgap between Ce3+ and Ce4+ states in cerium oxides, high oxygen mobility.•Inter conversion of Ce4+ to Ce3+ ratio enhances the photon-induced dye degradation.•Due to the larger cation, La3+ substituting for Ce4+ in the CeO2 lattice.•Ceria rich nanostructures like Ce2/La1 and Ce1/La1 there is no additional diffraction.•Shift in the peak position the difference in ionic size between Ce4+ and La3+.
We report the synthesis of high quality CeO2-CdO binary metal oxide nanocomposites were synthesized by a simple chemical precipitation and hydrothermal method. Cerium nitrate and cadmium nitrate were ...used as precursors. Composition, structure and morphology of the nanocomposites were analyzed by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). XRD pattern proves that the final product has cubic phase and the particle size diameter of the nanocomposites are 27nm, XRD results also indicated that the crystalline properties of the nanocomposite were improved without affecting the parent lattice, FESEM analysis indicates that the product is composed of spherical particles in clusters. The morphological and optical properties of CeO2-CdO nanosamples were characterized by HRTEM and DRS spectroscopy. The IR results showed high purity of products and indicated that the nanocomposites are made up of CeO2 and CdO bonds. Absorption spectra exhibited an upward shift in characteristic peaks caused by the addition of transition metal oxide, suggesting that crystallinity of both the metal oxide is improved due to specific doping level. TGA plots further confirmed the purity and stability of nanomaterials prepared. Hence the nanocomposite has cubic crystal lattice and form a homogeneous solid structure. From the result, Cd2+ ions are embedded in the cubic crystal lattice of ceria. The growth rate increases which are ascribed to the cationic doping with a lower valence cation. Ce-Cd binary metal oxide nanocomposites showed antibacterial activity, it showed the better growth inhibition towards p.aeruginosa. Exploit of photodegradation and photocatalytic activity of large scale synthesis of CeO2-CdO binary metal oxide nanocomposites was reported.
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•Design of CeO2/CdO nanospheres via a simple precipitation and hydrothermal process•The formation of CeO2/CdO nanocomposite with excellent crystalline nature•Exhibit the band gap of Ed=3.15eV (393nm), Ei=2.90eV (427nm)•CeO2/CdO nanospheres exhibit enhanced photocatalytic activity.•Antibacterial activity against pathogenic strains of p.aeruginosa
Binary metal oxide heterojunctions possibly will exclude the recombination of photogenerated charge carriers via interfacial charge transfer in assessment among the single-component photocatalytic ...material. Highly ordered samarium doped titania nanosphere have paid more attention to the exclusion of toxic organic pollutants. Tuning the shape, size, morphology, bandgap and defect optimization of titanium oxides (Sm2Ti2O7) improved as an enhanced catalyst which was synthesized by using the capping agent also acts as a reducing agent. Herein, we examine an environmentally pleasant Sm2Ti2O7 nanosphere with its various properties via assorted characterization techniques and wrapping of nanosphere makes them appropriate catalysts for the degradation of toxic dyes and show the highest efficiency via irradiation of visible light by declining the option of the exciton-recombination process. Therefore, the photocatalyst was found to produce reactive oxygen species (ROS) both in the presence and absence of light, which is responsible for the decomposition of dyes into small fractions. In addition, HRTEM study reveals that the nanospheres are highly porous nature with high active surface area and small grain size are reported in detail.
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