Bio-synthesis of cerium (IV) oxide nanoparticles (CeO
2
-NPs) has been performed through a sol-gel method that involved the utilization of Rheum Turkestanicum plant extract as the stabilizing agent. ...The obtained nanoparticles have been identified throughout FT-IR, UV-Vis, XRD, FESEM/EDX/PSA, and TGA/DTA techniques. The XRD pattern has been presented the cubic fluorite structure of CeO
2
-NPs, which had indicated the particle size about 30 nm. The UV-Vis spectrum of nanoparticles has presented a strong adsorption band. The FESEM/PSA images have exhibited the spherical shape of CeO
2
-NPs. Furthermore, the photocatalytic activity of CeO
2
-NPs has been investigated by performing the decolorization of MB, RhB, and MO dyes under UVA light, which are associated with sewage water pollutants. The results of MTT assay has reported that the cytotoxicity effect of CeO
2
-NPs on PC12 cell lines had not been dependent on concentration, as well as an indication of the lack of any significant toxicity by the nanoparticles on cancer cells.
The development of electrocatalysts with high activity and stability for oxygen evolution reaction (OER) is critically important, the one being regarded as the bottleneck process of overall water ...splitting. Herein, we fulfill significant OER improvement in both activity and stability by constructing a class of Ni(OH)2–CeO2 supported on carbon paper (Ni x Ce y @CP) with an intimate hydroxide (Ni(OH)2)–oxide (CeO2) interface. Such interface largely promotes the OER activity with a low overpotential of 220 mV at 10 mA cm–2 and a small Tafel slope of 81.9 mV dec–1 in 1 M KOH. X-ray photoelectron spectroscopy analysis shows that the intimate interface induced by the strong electronic interactions between Ni(OH)2 and CeO2 involves the modulation of binding strength between intermediates and catalysts, making a great contribution to the OER enhancement. Importantly, such intimate interface structures can be largely maintained even after a long-time stability test. We have further demonstrated that, when pairing the Ni4Ce1@CP after phosphorization (P–Ni4Ce1@CP), the Ni4Ce1@CP and P–Ni4Ce1@CP assembly is highly active and stable for overall water splitting with a low voltage of 1.68 V at 25 mA cm–2 and negligible stability delay over 30 h of continuous operation, which are much better than the commercial Ir/C and Pt/C.
The purpose of this study was to characterize the structural, optical, and physical properties of various kinds of glasses based on the 50TeO2–30B2O3-(20-x)Li2O-xCeO2 system (x = 0, 0.5, 1, 2, 3, 4, ...5, 10, 15, 20). Consequently, ten glass samples were produced by melting-annealing. Calculations of the densities of the synthesized glasses were performed using the Archimedes technique. The sample's structural, optical, physical, and radiation interaction properties were determined using XRD analysis, Raman spectroscopy, and advanced modelling techniques with FLUKA code, yielding optical band gap, refractive index, and Urbach energy values. By increasing the CeO2 reinforcement from 0 to 20 mol %, the glass densities rose from 4.0614 to 4.7519 g cm−3. The transmittance spectra of TBLC glasses were found in the range of 200–1100 nm. Our findings showed that the lowest Urbach energy belonged to the TBLC1 sample, and the highest Urbach energy belonged to the TBLC20 sample. When the CeO2 ratio was raised, the optical transmittance and absorption characteristics changed nearly monotonically, suggesting that these qualities may be calculated and controlled using the CeO2 additive, as shown in this experiment. By substituting CeO2 for Li2O inside the structure, it was possible to substantially enhance the optical band gap. Additionally, at simulated energies greater than 0.02 MeV, the gamma-ray linear attenuation coefficient rises monotonically with CeO2 reinforcement. Consequently, linear attenuation coefficients were reported as 125.843 cm−1, 127.601 cm−1, 129.211 cm−1, 132.312 cm−1, 135.166 cm−1, 138.705 cm−1, 141.288 cm−1, 156.690 cm−1, 172.393 cm−1, 186.811 cm−1 for TBLC0, TBLC0.5, TBLC1, TBLC2, TBLC3, TBLC4, TBLC5, TBL10, TBLC15 and TBLC20 at 0.015 MeV, respectively. It can be concluded that combination of high-concentration CeO2 and TeO2–B2O3 glass is an excellent synergetic tool for combining structural, optical, and radiation properties when combined with other materials.
•This study investigates structures and thermodynamic stability of Nb-CeO2 configurations.•Most stable Ce-Nb-O configuration is obtained when Nb atoms supersede top-layer o atoms.•Calculated lattice ...constants reflects very well our measured value.•EDS measurements provided relative atomic distributions.•Results herein could be useful in fine-tuning catalytic attributes of ceria-based materials.
Ceria (CeO2) displays a profound catalytic capacity even when utilized as a stand-alone material. Catalyzed reactions by ceria could be enhanced when it is decorated with a trace content of d or f-metals. This study addresses the stability and properties of niobium incorporated ceria surfaces. Doping a trace amount of metals often alter catalytic properties of the host metal oxide. Herein, we investigate mixed Ce-Nb-O oxides with a prime focus on the surface free energy, lattice constant, as well as atomic charges and density of states. It was found that the most stable Ce-Nb-O configuration is obtained when Nb atoms supersede top-layer O atoms at highest niobium occupancy where the surface energy decreases by 0.3 eV/Å2 compared to neat ceria surface. It was also shown that the changes in lattice constants in this configuration is in accord with data obtained from X-Ray Diffraction patterns. Results from this study could be useful in fine-tuning catalytic attributes of ceria-based materials.
•First instance of using Cerium (IV) oxide coated surfaces for oil-water separation.•Surfaces coated with CeO2 particles are superhydrophobic and superoleophilic.•High efficiency of oil/water ...separation achieved when using coated surfaces.•Analytical model used for explaining wetting properties and separation mechanism.
In this work, we report the preparation of superhydrophobic and superoleophilic surfaces on stainless steel meshes by spray-coating of Cerium(IV) oxide (CeO2) nanoparticles obtained by a co-precipitation method. The synthesized particles and the coated meshes were characterized using advanced techniques. Scanning electron microscopy images showed the particles to be present in distinct lumps; merged with each other on calcination to give a homogeneous structure. Transmission electron microscopy analyses showed the agglomeration of individual particles to form the clusters. Contact angle measurements revealed the superhydrophobic and superoleophilic nature of the modified mesh surface in air. Fourier transform infra-red analyses of the synthesized particles showed the characteristics peaks of CeO2 found in commercial samples. X-ray photoelectron spectroscopy of the glass coated with ceria confirmed the predominant presence of Ce4+ that also explained the wetting behavior. Oil-water separation studies using a simple gravity-driven setup showed high separation efficiency of an oil water mixture. An analytical model is discussed in detail to account for the wetting behavior and efficacy of the prepared surfaces in separating the two fluids. To summarize, this work presents a very simple and effective route for oil-water separation with high efficiency.
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•A new electrochemical sensor is developed to measure trace amount of fenitrothion.•The nanocomposite was characterized by various analytical methods.•CeO2/rGO nanocomposite has ...synergetic effect on the oxidation of fenitrothion.•Fenitrothion can be measure from 0.025 to 2.00 μM with a detection limit of 3 nM.
Fenitrothion is one of the common organophosphorus pesticides that is widely employed for insect control in agriculture. Here, cerium oxide@reduced graphene oxide nanocomposite (CeO2/rGO) was successfully prepared to apply as an efficient mediator for electrochemical detection of fenitrothion. The CeO2/rGO nanocomposite was characterized by various analytical methods including FT-IR spectroscopy, X-ray diffraction spectroscopy and electrochemical techniques. Also, the morphology and characteristic of CeO2/rGO were monitored using microscopic images of transmission electron microscopy and atomic force microscopy. CeO2/rGO was employed to modify glassy carbon electrode (GCE) and resulting data was compared to rGO-GCE and unmodified GCE and some other reported sensors in literature. The electrochemical studies represented that CeO2/rGO improved the GCE by decreasing the working potentials to more acceptable one (around 0.00 V vs. Ag/AgCl) with the observable increases in the voltammetric responses towards fenitrothion concentration. The quantitative data were obtained using differential pulse voltammetry (DPV) with a linear range of 0.025–2.00 μmol L−1 fenitrothion. Moreover, its detection limit was obtained as 3.0 nmol L−1 fenitrothion. Finally, CeO2/rGO-GCE represented high selective sensing towards fenitrothion in the presence of common interference species present in real well water and spring water samples provided from agricultural environment.
Transmission electron microscopic image of NICMO showed the spherical shaped, unevenly distributed discrete clusters that indicated agglomeration of crystalline particles (10–20nm) held together with ...some void space facilitating solvent flow.
•Eco-friendly, green synthetic route was exploited for material synthesis.•Characterized as crystalline agglomerated nanoparticles with microporosity.•Groundwater occurring ions have adversely influenced arsenic sorption kinetics.•Reaction kinetics obeyed pseudo-second order model very well.•Bicarbonate and phosphate hinders As(V) sorption more compared to As(III).
Here, we aim to develop an efficient material by eco-friendly green synthetic route that was characterized to be nano-structured. The thermal stability of the sample was well established from the consistent particle size at different temperature and also, from differential thermal analysis. The bimetal mixed oxide contained agglomerated crystalline nano-particles of dimension 10-20nm, and its empirical composition as FeCe1.1O7.6. The surface area (m2g-1), pore volume (cm3 g-1) and maximum pore width (nm) obtained from BET analysis were found to be 104, 0.1316 and 5.68 respectively. Use of this material for estimating arsenic sorption kinetics in presence of some groundwater occurring ions revealed that the pseudo-second order kinetic model is unambiguously the best fit option to describe the nature of the reactions. Groundwater occurring ions exhibit a notable decrease of As(V)-sorption capacity (no other ion>chloride∼silicate>sulfate>bicarbonate>phosphate). However, As(III)-sorption capacity of the bimetal mixed oxide was nominally influenced by the presence of the above ions in the reaction system. Rate determining step of arsenic sorption reactions was confirmed to be a multistage process in the presence of the above ions at pH∼7.0 and 30°C.
Cerium (IV) oxide (CeO2) exhibit anti-inflammatory activity via scavenge free radicals and decreasing the oxygen species (ROS) production. Here we aimed to exhibit the therapeutic effect of this ...nanoparticle in experimental colitis models.
Cerium oxide nanoparticles (CeONPs) were synthesized via using UiO-66 as a precursor. We used dextran sodium sulfate (DSS) to induce colitis in experimental models to investigate the anti-inflammatory effect of CeONPs. Colitis models are divided into four groups to receive the treatment, including control, colitis, cerium oxide, and sulfasalazine. We evaluated the therapeutic effects of CeONPs for the increased colitis clinical symptoms and attenuated the histological damage to colon tissue in colitis.
This nanoparticle was significantly able to reduce the clinical symptoms of colitis. Moreover, CeONPs can enhance the disease activity index such as body lose weight, diarrhea, rectal bleeding, colon length, and spleen weight. Moreover, CeONPs showed a significant reduction in the histological characteristics of the colitis models.
These results suggest that CeONPs can be considered as promising therapeutic agents in treating the ulcerative colitis.
Thermochemical splitting of a mixture of CO2 and water into syngas (and methane) remains a viable approach toward an industrial-scale treatment of CO2 emission. However, most deployed catalysts ...encompass expensive metallic ingredients such as Pd or Pt. In an integrated experimental-modelling approach, this work reports a high conversion of CO2 over alternative and cost-effective configurations. Ceria-based catalysts are proven to be effective in numerous catalytic processes owing to the facile switch in the Ce redox cycle. Evolution of H2 and CO from thermochemical splitting of water and carbon dioxide is an important process in the production of syngas and in fuel cell applications. In this study, NbOx ceria catalysts are prepared, characterized, and applied for production of syngas via the thermochemical splitting of CO2 and gaseous water. It was observed that presence of Nb in the ceria matrix up to 12 wt%, increases the reaction yield at higher temperature (up to 79% CO2 conversion with 80% selectivity to syngas at 600 ºC). Moreover, the catalytic reaction was found to display a higher selectivity towards syngas over the ceria supported catalysts. The attained conversion is higher than other ceria-supported catalysts such as Rh-CeO2, CeO2-ZrO2, and V2O5-CeO2. Mapped-out reaction pathways by DFT calculations portray accessible routes into syngas. Results provided herein should be useful to optimize a continuous process for the valorization of CO2 into syngas over relatively affordable a catalytic formulation.
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•This study investigates thermochemical splitting of CO2/H2O into syngas over Nb-CeO2 catalyst.•Formulated catalysts were characterized by a wide array of methods.•Up to 79% CO2 conversion is attained with 80% selectivity into syngas at 600 ºC.•Most governing reaction steps inure accessible activation energies.•Conversion of CO2 is sensitive to the deployed load of Nb.
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