Effect Of Ce Doping Research Articles

The catalytic decomposition of CH4 using Ce-doped Fe/CaO-Ca12Al14O33 catalyst and its regeneration performance for H2 production

The catalytic decomposition of CH4 using low cost and non-toxicity Fe-based catalysts is a prospective method for H2 production. The regeneration process of iron-based catalysts involves CO2 emission and incomplete conversion of carbon deposition. In this work, a novel catalytic decomposition of CH4/regeneration process was proposed using the Ce-doped Fe/CaO-Ca12Al14O33 catalyst for H2 production. To remove the carbon deposition in the catalyst, the regeneration stage includes four steps: solid carbon production by vibratory separation, steam gasification of residual carbon deposition to produce H2 where CO2 is captured by CaO to form CaCO3, calcination of CaCO3 to produce CaO and pure CO2, methanol production by CO2 and H2 from carbon deposition gasification. The effects of Ce doping on the catalysis/regeneration performance of Fe/CaO-Ca12Al14O33 catalysts were studied, and the Ce-doped Fe/CaO-Ca12Al14O33 catalyst was compared with Cu-, Zn-, and Mn- doped Fe/CaO-Ca12Al14O33 catalysts. The solid carbon obtained from the catalytic decomposition of CH4/regeneration cycles was characterized. The Ce-doped Fe/CaO-Ca12Al14O33 catalyst shows excellent catalysis, CO2 capture, and stability performance in the catalytic decomposition of CH4/regeneration cycles. The average CH4 conversion is 90.02% in the first cycle, which decreases to 80.01% after 8 cycles. Carbon nanotubes are the main forms of obtained solid carbon with the favorable pore structure. The doping of Ce improves the effective adsorption sites for CH4 and CO2. Carbon deposition in the catalyst is efficiently removed by steam gasification. In addition, CeO2 promotes the electron transfer, oxygen vacancy generation, and Fe3C decomposition, which leads to superior catalytic performance and resistance to deactivation of the catalyst. The CeO2-doped Fe/CaO-Ca12Al14O33 catalyst is promising for H2 production via catalysis/regeneration cycles.

Ce Doping Effects on the Hydrogen Sensing Properties of Graphene/SnO2-Based Sensors.

The development of a sensor capable of selectively detecting hydrogen levels in the environment holds immense importance for ensuring the safer utilization of hydrogen energy. In this study, a hydrogen sensor made of Ce-doped single-layer graphene (SLG)/SnO2 composite material was fabricated using a hydrothermal method. The study examined the impact of varying Ce doping concentrations on the hydrogen sensing capabilities of the SLG/SnO2 matrix. The results show that the SLG/SnO2 hydrogen sensor doped with 2 mol% Ce demonstrated optimal performance at a humidity of 20%. It operated most efficiently at 250 °C, with a response of 2.49, representing a 25.75% improvement over the undoped sample. The response/recovery times were 0.46/3.92 s, which are 54.9% shorter than those of the undoped sample. The enhancement in hydrogen sensitivity stems from the synergistic effect of Ce and SLG, which facilitates the coexistence of n-n and p-n heterojunctions, thereby increasing carrier mobility and refining grain structure. Analysis via X-ray photoelectron spectroscopy (XPS) reveals that Ce increases the material's oxygen vacancy concentration, enhancing its hydrogen sensitivity. Ce-doped SLG/SnO2, with its robust hydrogen sensitivity, represents one of the leading candidates for future hydrogen gas sensors.

Significantly enhanced piezoelectric response in Aurivillius Bi3TiNbO9 ceramics simply by Ce doping

Bi3-xCexTiNbO9 (BTN-100xCe, x = 0, 0.01, 0.03, 0.05, 0.07, 0.09, 0.11) piezoelectric ceramics with ultra-high Curie temperature were fabricated by a solid-state sintering method, and the effect of Ce doping on the structure, dielectric and piezoelectric properties of the ceramics was investigated. All ceramic samples possess a single Aurivillius phase and Ce ions enter both A- and B-sites. Dense microscopic morphology with a remarkable decrease of grain size can be observed due to Ce doping. The resistivity markedly increases after Ce modification, and a significantly enhanced piezoelectric constant d33 of 17.1 pC/N can be achieved in the optimized BTN-7Ce ceramics, which is nearly 6 times that of pure Bi3TiNbO9 (d33 ≈ 3 pC/N). In addition to ultra-high Curie temperature (TC = 886.5 °C) and relatively high resistivity (ρ = 1.2 × 106 Ω cm @ 500 °C), the BTN-7Ce ceramics should be very promising for piezoelectric sensor under the application in high temperature conditions.

Effect of Ce-Doping on the Structural, Morphological, and Electrochemical Features of Co3O4 Nanoparticles Synthesized by Solution Combustion Method for Battery-Type Supercapacitors

This study investigates the potential of cerium (Ce) doping to improve the performance of cobalt oxide (Co₃O₄) nanoparticles as battery-type supercapacitor electrodes. Pure Co₃O₄ nanoparticles were synthesized via a solution combustion method and then doped with 2.5% (Ce-Co3O4) and 5% Ce (CeO2-Co3O4). Comprehensive characterization, including X-ray diffraction (XRD), Raman spectroscopy, and field emission scanning electron microscopy (FESEM), was used to analyze the impact of Ce doping on the material properties. XRD analysis confirmed the successful incorporation of Ce into the Co₃O₄ structure, with distinct CeO2 phases forming at higher doping levels. Ce doping resulted in decreased crystallite size and peak intensity, indicating reduced crystallinity and increased defect concentration. Raman spectroscopy corroborated these findings, showing a redshift that suggests weakened metal-oxygen bonds and smaller grain sizes due to Ce³⁺ incorporation. FESEM images demonstrated that Ce doping effectively reduced nanoparticle agglomeration, with 2.5% doping leading to smaller particles and 5% doping promoting a 2D flake-like morphology with increased porosity. Nitrogen adsorption-desorption measurements revealed a significant increase in surface area and pore volume for CeO2-Co₃O₄, facilitating improved electrolyte diffusion and reduced resistance, thereby enhancing electrochemical performance. Evaluation of the electrochemical properties of undoped and Ce-doped Co₃O₄ materials revealed a battery-like response in a three-electrode configuration. Notably, the CeO2-Co3O4 exhibited a superior specific capacity of 603.3 C g-1 at a current density of 1 A g-1, significantly exceeding the values of 368.5 C g-1 and 127.1 C g-1 achieved by Ce-Co3O4 and undoped Co3O4, respectively. Furthermore, the CeO2-doped Co3O4 demonstrated exceptional cyclic stability, retaining 87% of its initial capacity after undergoing 5000 charge-discharge cycles at a high current density of 10 A g-1. These results suggest that Ce doping is a promising strategy for optimizing Co₃O₄-based battery-type electrode materials, potentially leading to the development of high-performance and cost-effective energy storage systems.

Effect of Ce doping on MoO3 thin films for room temperature ammonia sensing application

In this work, we report the fabrication and gas sensing application of undoped, and Ce doped (1, 2, 3, 4, 5 wt%) MoO3 thin films via simple, effective, and low-cost nebulizer spray pyrolysis method. The crystal structure of the prepared thin films was found to be monoclinic by the prominent peaks observed at (001), (002) planes and the primary peak intensities increases from undoped to 3% Ce doped MoO3 thin film. The morphology of the samples was studied by FESEM, and the films have nanofibrous network embedded with nanorods spread over the surface of the nanofibers. The optical properties were characterised by the UV–vis spectroscopy and observed that the film’s energy band gap declines from 3.28 to 3.04 eV due to the Ce dopant which alters the energy levels of the conduction and valence bands of the host by oxygen defects. The defects were analysed by the PL spectroscopy, and it proved that the PL emission peaks arose due to the oxygen deficiencies. The 3% Ce doped MoO3 produced higher PL emission intensity indicated that the higher oxygen defects sites are the cause. The gas sensing responses were measured for the pristine and 1, 2, 3, 4 and 5 wt% Ce doped MoO3 gas sensors increase from 6.48 × 102 to 1.67 × 104 and found to be higher for the 3% Ce doped sensor to detect ammonia gas. The significant gas sensing property such as rise time and fall time were observed to be least for the 3% Ce doped MoO3 thin film was 54 and 5 s. This study revealed that 3% Ce doped MoO3 thin film could be an efficient prominent ammonia gas sensor at room temperature in future.

Effect of Ce-doping on the structural, optical and photoluminescence characteristics of nano Zn0.75Cd0.25S

Nano Zn0.75CexCd0.25S samples with different doping amounts of cerium (x = 0.0, 0.02, 0.04, 0.06) were synthesized using the thermolysis approach. The possibility of Ce ion incorporation into the ZnS0.75Cd0.25S lattice either substitutionally for Zn/Cd or interstitially into the voids of the lattice was examined using Rietveld refinement analysis based on X-ray diffraction (XRD) data. The lattice parameters, crystallite size and microstrain of the formed samples were computed. Particles with homogeneous spherical morphology can be seen using TEM technique with nano size of 2–4 nm, approving the values obtained from XRD. The optical properties of the prepared samples were examined by the diffuse reflectance spectroscopy technique. The optical energy gap value of Zn0.75Cd0.25S is 2.79 eV. As the Ce content rose, this value decreased until it reached 2.68 eV. The refractive index (n) values derived from numerous models, along with the average n values for all samples were calculated. The incorporation of Ce doping into nano Zn0.75-xCexCd0.25S samples results in an increase in their dielectric constants, suggesting their potential role for energy storage applications. With a rise in Ce doping, the non-linear optical parameters of Zn0.75-xCexCd0.25S were improved. Gaussian function fitting was used to decompose the photoluminescence (PL) emission of different samples. Upon doping with Ce, a noticeable reduction in the PL intensity was observed. The sample without any doping showed a cyan color, whereas the doped samples exhibited a cyan-green color.

Nanoflower-like cerium-doped ZnO photocatalyst deposited by spray pyrolysis for the degradation of methylene blue dye

In this study, the photodegradation of methylene blue (MB) dye and photocatalytic activities of pure ZnO and ZnO:Ce (2%, 4%, 6%, %8) films deposited with USP, an economical technique, were examined. The effect of Ce-doping on the optical, structural, surface and photocatalytic properties of the films was investigated using XRD, UV–Visible spectrophotometry, spectroscopic ellipsometry (SE), photoluminescence spectrometry, X-Ray Photoelectron Spectroscopy (XPS), field emission scanning microscope (FESEM) and atomic force microscope (AFM). In the morphology analyzes of the films, a chrysanthemum-like nanoflower structure was observed as a result of Ce-doping. Photoluminescence spectra were taken in order to determine the trap levels formed in the structure of ZnO:Ce films to be used in photocatalytic applications. Consequently, the photocatalytic properties of ZnO:Ce films were found to vary significantly depending on the surface morphology of the photocatalyst and surface defects (zinc interstitial, oxygen vacancies).

The effect of Ce doping on the structural, optical, and photocatalytic degradation of Mn–Co nanoferrites

This work demonstrates the preparation of Ni0.5Mn0.25Co0.25CexFe2-xO4 spinel nanoferrites (NMCCF nanoferrites) using the citrate combustion method. This study also investigated the characteristics of their structure, optics, and ability to degrade under light. The lattice strain and crystallite size of each NMCCF nanoferrite were measured by evaluating the XRD results using Williamson-Hall plots. The crystallite size was between 40 and 78 nm. The hopping lengths, bond lengths, surface areas, and densities of all NMCCF nanocrystals were measured and calculated. FTIR analysis showed two strong frequency bands at 571 and 390 cm−1, which are characteristic of spinel ferrites. SEM was used to investigate the particle size, composition, and distribution of the nanoferrites in the NMCCF sample. Scanning electron microscopy (SEM) analysis revealed the presence of spherical NMCCF nanoparticles and their tendency to aggregate. The Kubelka-Munk function and Tauc plots were used to predict the direct allowed Eg value of the NMCCF samples. NMCCF0, NMCCF1, NMCCF2, NMCCF3, NMCCF4, and NMCCF5 exhibited bandgap values of 1.515, 1.545, 1.506, 1.507, 1.499, and 1.473 eV, respectively. The behavior of Eg can be explained based on two criteria: doping impact and particle size. A comparative analysis of the photocatalytic degradation of the ideal sample (Ni0.5Mn0.25Co0.25Ce0.1Fe1.9O4) and other published photocatalytic materials demonstrated that the NMCCF5 nanoferrite exhibited a greater ability to remove methylene blue dye (97.38 %, within 60 min) compared to those materials. In addition, this comparative investigation demonstrated the enhanced stability of photocatalytic degradation capability exhibited by the current nanoferrites (with just a 1.55 % loss in efficiency after five cycles). This paper introduces an innovative method for producing spinel nanoferrites, with a specific focus on their structural, optical, and photocatalytic properties, which can be useful in the field of water treatment.

Magnetic properties and microstructure of Ce and Zr synergetic stabilizing Ti-lean SmFe12-based strip-casting flakes

Recently ThMn12-type samarium iron alloys have been promising materials for permanent magnets. Due to the high abundance and low cost, Ce as a possible stabilizer can be introduced into ThMn12-type alloys. The effect of Ce doping on the magnetic moment and phase stability in Ti-lean (Ce,Sm,Zr)(Fe,Co,Ti)12 compounds were predicted by the first-principles calculations. The CexSm0.8-xZr0.2(Fe0.8Co0.2)11.5Ti0.5 (x = 0–0.8) alloys with ThMn12 structure were produced by strip-casting into flakes by a wheel speed of 1.5 m/s and annealed at 1000 °C for 24 h. The Ce0.8Zr0.2(Fe0.8Co0.2)11.5Ti0.5 annealed flake shows a high saturation magnetization value of 13.6 kGs at room temperature. With the increase of Ce substitution in the annealed flakes, the content of α-(Fe,Co,Ti) phase decreases and the saturation magnetization increases. The 1:12 phase and the 1:9 phase have an orientation relationship that can be expressed as [0 0 –1]1:12//[100]1:9 and (020)1:12//(010)1:9. Besides, annealing process promotes the formation of 1:12 phase transformed from 1:9 phase. Coercivity is expected to be improved by obtaining uniform microstructure and suppressing the formation of soft α-(Fe,Co,Ti) phase in the ThMn12-based alloys.

Effect of Ce doping on electromagnetic characteristics and absorbing properties of M-type barium ferrite

In this study, Ce3+-doped M-type barium ferrite BaCexFe12-xO19 (x = 0 ∼ 1.2) was prepared by sol-gel method. The effects of Ce3+ doping on the crystal structure, microstructure, electromagnetic properties and absorption properties of M-type barium ferrites were investigated. The results indicate that the crystal structure remains unchanged with the increase of Ce3+ doping. The crystal size of Ce3+ doped barium ferrite is in the micro-meter range, and the grain size remains almost constant with increasing doping. The addition of Ce3+ to the BaFe12O19 samples resulted in significant improvements in their electromagnetic and microwave absorption properties. These improvements were mainly due to the synergistic effect of magnetic and dielectric losses. Among the samples doped with different concentrations of Ce3+, BaCe0.2Fe11.8O19 exhibited the best absorption performance, which has a minimum reflection loss of −58 dB and an effective absorption bandwidth of 9.44 GHz at a matched thickness of 2.3 mm. This study proposes an efficient electromagnetic wave absorber with a wider effective absorption bandwidth.

Effect of Ce doping and MOF-derived structure on gas sensing performance of SnO2 to ethylene glycol

In order to enhance the gas sensing performance of SnO2-based sensor, different content of 1,3,5-benzenetricarboxylic acid (BTC) and stannous sulfate with molar ratio 0.5:1, 1.5:1, 2:1 were used to prepare the metal–organic frameworks (MOFs), Sn-BTC, by solvothermal method, and then calcined at 500 °C for 3 h to obtain SnO2 derived from MOF structure. The results showed that SnO2-1.5 had the best gas sensing performance at the optimal operating temperature of 160 °C, the response value to 100 ppm ethylene glycol was 64.69 and the response/recovery time was 13/3 s, respectively. Meanwhile, in order to further improve the sensitivity, different content of cerium nitrate hexahydrate (0.25, 0.75, 1.25 mol%) were used to prepare Ce doped Sn-BTC-1.5 and then the derived SnO2 doped with Ce was obtained by calcination. The SnO2-Ce-0.75 sensor was tested to have a maximum response value of 132.90 at 160 °C and a response/recovery time of 165/7 s.

Cerium-doped SnS micron flowers with long life and high capacity for hybrid supercapacitors

Supercapacitors with long life and high power density can be used in power tools and wind power equipment. However, increasing energy density without sacrificing advantages remains a major challenge, which limits their practical application. Therefore, efforts have been made to manufacture supercapacitors with high capacitance and long life. Ce-doped SnS micron flowers grown on nickel foam (Ce@SnS/NF) have been synthesized using a facile solvothermal method. The effect of Ce doping on the SnS, where Ce doping confined the growth of Ce@SnS to form smaller nanosheets and provided more active sites, resulting in the enhancement of the capacity and cycle stability, has been explored. In a three-electrode system, the specific capacitance increased from 1237 F/g (171.8 mAh/g) to 2549 F/g (354.0 mAh/g) at 2 A/g, and the stability was 85.5 % after 10,000 cycles at 10 A/g. A hybrid supercapacitor (Ce@SnS/NF (+)//AC (–)) assembled from Ce@SnS/NF and activated carbon as cathode and anode, respectively. The device has an energy density of 48.83 Wh/kg at 824.91 W/kg and long cycle stability (91.6 % retention after 20,000 cycles at 5 A/g). Moreover, the supercapacitor can power a white light-emitting diode (LED) for 15 min, so the Ce-doped SnS cathode has vast application prospects in supercapacitors.

Oxygen adsorption capability and electrochemical properties induced by oxygen vacancies in cerium-doped LaFeO3 perovskite oxide

The effect of Ce doping on the electrochemical properties of LaFeO3 perovskite oxides was investigated in terms of the oxygen adsorption capability and polarization resistance. The Ce-doped LaFeO3 perovskite oxide had a single perovskite phase with an orthorhombic structure. The presence of oxygen vacancies was confirmed by EPR spectra and O 1 s core-level spectra. An O2 temperature-programmed desorption profile demonstrated an increase in the quantity of surface-active oxygen species, with LCFO5 exhibiting the highest oxygen adsorption capability. The area-specific resistance gradually decreased with the cerium doping from 11.36 Ωcm2 (LFO) to 4.65 Ω cm2 (LCFO5). A notable decrease of 68 % was confirmed in the polarization resistance related to the mass transfer, from 7.66 Ωcm2 (LFO) to 2.44 Ωcm2 (LCFO5). This significant decrease indicates an enhanced oxygen reduction reaction activity, which is attributed to the accelerated oxygen adsorption reaction.

New Insights into the Effect of Ce Doping on the Catalytic Performance and Hydrothermal Stability of Cu-USY Zeolite Catalysts for the Selective Catalytic Reduction of NO with NH3

5Cu-USY and Ce-doped 5Cu8Ce-USY zeolite catalysts were prepared by the conventional impregnation method. The obtained catalysts were subjected to the hydrothermal ageing process. The catalytic performance of the selective catalytic reduction of NOx with NH3 (NH3-SCR) was evaluated on both fresh and aged catalysts. Physical/chemical characterizations such as X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), and X-ray photoelectron spectroscopy (XPS) were performed, along with detailed in situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) experiments including CO adsorption, NH3 adsorption, and NO + O2 reactions. Results showed that, for the 5Cu-USY catalyst, hydrothermal ageing treatment could somehow improve the low-temperature SCR activity, but it also led to significant formation of unfavorable byproducts NO2 and N2O. Such an activity change can be attributed to hydrothermal ageing inducing the migration of isolated Cu+ species in the sodalite cavities towards the super cages of the USY zeolites. The increased content of Cu+ species in the super cages was beneficial for the low-temperature activity improvement, but, at the same time, it also facilitated ammonia oxidation at high temperatures. Ce doping after hydrothermal ageing has a “double-edged sword” effect on the catalytic performance. First of all, Ce doping can inhibit Cu species migration by self-occupying the internal cage sites; thus, the catalytic performance of 5Cu8Ce-USY-700H remains stable after ageing. Secondly, Ce doping introduces a CuOx–CeO2 strong interaction, which facilitates lattice oxygen mobility by forming more oxygen vacancies so as to increase the concentration of surface active oxygen. These changes, on the one hand, could help to promote further oxidative decomposition of nitrate/nitrite intermediates and improve the catalytic performance. But, on the other hand, it also causes the byproduct generation to become more severe.

Effect of Ce-doping on the phase composition and aqueous stability of Gd2Hf2O7 ceramic as nuclear waste forms

A series of Ce-doping nanograin Gd2CexHf2-xO7 (0.0 ≤ x ≤ 2.0) ceramic samples as nuclear waste forms were prepared, and their microstructure, phase evolution, and aqueous durability were systematically studied. The results revealed that the original Gd2Hf2O7 sample comprised a single pyrochlore structure after sintering at 1673 K, but all the Gd2CexHf2-xO7 (0.5 ≤ x ≤ 2.0) samples assumed defective fluorite structures with Ce-doping. As the xCe value increased from 0.0 to 2.0, the average grain size of the samples gradually increased from 162 nm to 599 nm, whereas the relative density (measured density/theoretical density) of the samples gradually increased from 91.12% to 93.93%. The normalized release rates of Ce element in the Gd2Ce2O7 sample after 42 days were slightly lower than those of Hf element in the Gd2Hf2O7 sample owing to the lower porosity of the Gd2Ce2O7 sample, and the bond dissociation energy of Ce–O (∼795 kJ/mol) was slightly higher than that of Hf–O (∼791 kJ/mol). Moreover, the normalized release rates of all considered elements were lower than 10−5 g m−2 d−1, indicating that the samples had excellent chemical stability.

Effect of Ce doping on ferroelectric HfO2 from first-principles: Implications for ferroelectric thin films and phase regulation

In this work, the effect of Ce doping on the structure and oxygen defects of ferroelectric HfO2 is studied by first-principles calculation. According to the formation energy of Ce doping and the influence of Ce doping on the formation enthalpy of each phase, it is concluded that the concentration of Ce doping is 8–9.375 formula unit% which is most beneficial to the formation of ferroelectric orthorhombic phase. The phase transition from ferroelectric orthorhombic phase to cubic phase will occur when the doping concentration is greater than 12.5 formula unit%. The mechanism of Ce doping was also studied. From the view of electric balance, it is concluded that the existence of Ce3+ will promote the formation of oxygen vacancies in HfO2. These findings are helpful for the preparation of Ce-doped HfO2 ferroelectric thin films and deepen the understanding of the Ce doping mechanism.

Structural, thermal properties and improved ionic conductivity of cerium-doped Li0.5+xLa0.5-xCe2xTi1-xO3 solid electrolyte materials

A series of Ce-doped Li0.5+xLa0.5-xCe2xTi1-xO3(x = 0.0, 0.025, and 0.05) ionic conductive crystalline oxides were produced by a solid-state reaction process. The effect of Ce-doping on the thermal, structural, electrical, and dielectric characteristics of Li0.5La0.5TiO3 was investigated using TGA/DTA, XRD, SEM/EDS, FT-IR spectroscopy, and impedance spectroscopy techniques. The TGA/DTA spectra confirmed the phase transformation and weight loss of the mixed precursors. The XRD and FT-IR analysis revealed that the materials exhibited a cubic system with a perovskite phase, which corresponds to the Pm3m space group. The EDS analysis clearly detected the presence of all elements except Li in the Li0.5+xLa0.5-xCe2xTi1-xO3 materials. The electrical conductivities were found to be 3.9 × 10−5 S/cm for Li0.525La0.475Ce0.05Ti0.975O3, and 3.1 × 10−5 S/cm for Li0.55La0.45Ce0.1Ti0.95O3, which are higher than that of Li0.5La0.5TiO3 (1.7 × 10−5 S/cm). This confirmed that the incorporation of a small quantity of Ce4+ ions can enhance the electrical conductivity of Li0.5La0.5TiO3 sample.

Promotion Effects of Ce-Doping on Catalytic Oxidation of Ethane over Pt/CexTi1−xO2

The catalytic oxidation of VOCs is widely acknowledged as the most available technology to reduce air pollution. Among the catalysts for VOCs, 1 wt%-Pt/TiO2 catalysts using metal as a doping element have shown amazing potential in many fields. However, achieving high catalytic performance at relatively low temperatures based on the activation of molecules is still a formidable challenge owing to the catalytic activity being highly dependent on temperature. Here, the role of the rare earth metal Ce in the catalytic oxidation of ethane was studied by preparing Pt/CexTi1−xO2 (x = 0, 0.002, 0.005, 0.01, 0.02, and 0.05) catalysts. When the Ce/(Ce+Ti) molar ratio was 0.01, Pt/Ce0.01Ti0.99O2 achieved 90% ethane conversion at 436 °C. This reaction temperature is 15% lower than that for Pt/TiO2. The characterization results show that the doping of Ce caused lattice expansion of TiO2 and its distortion brought about by oxygen vacancies. Additionally, the appropriate amount of Ce-doping can alter the interaction between the active component Pt and the carrier TiO2, thereby improving the activity and concentration of the active surface lattice oxygen species of the catalyst. These results provide a foundation for the design of the catalytic oxidation of VOCs under mild operating conditions.

Study of Ce-doping effects on optical, morphological, magnetic, structural, and antibacterial properties of NiCr2O4 ceramics

We present a comprehensive study on optimization of microwave method routes for producing well-crystalline spinel chromite, nicr2o4 and Ce-doped nicr2o4. All samples were characterized by powder X-ray diffraction (XRD) and vibrational spectroscopy in order to evaluate their phase composition, particle size and micro-strain. Selected samples were investigated by adopting transmission electron microscopy (TEM) and optical spectra (absorption spectroscopy & photoluminescence, PL). The presence of large concentration of anion deficiency and its related defects, are reflected in the intense emission of PL spectra and in lowering the band gap value with respect to the bulk counterpart. As the Ce concentration increases, the size of the nanoparticles reduced from ∼33 to 22 nm. The effects of the cation distributions on geometrical variations of electronic and magnetic properties of nicr2o4 can be interpreted as dominated by the local behavior of Ni2+ at octahedral and Cr3+ tetrahedral sites. In the present work, the results indicate that the substitution of Ce ion into nickel chromite particles, enhances effects of the magnetic, optical properties, and also enhances the antibacterial properties.

Effect of Ce doping on radiation resistance of erbium-doped fiber for space laser communication

Effect of Ce doping on radiation resistance of erbium-doped fiber for space laser communication