Shifting the band gap from UV to visible region in cerium oxide nanoparticles

Thill, Alisson S.; Lobato, Francielli O.; Vaz, Maurício O.; Fernandes, Willians P.; Carvalho, V. E. de; Soares, E.A.; Poletto, Fernanda; Teixeira, Sérgio R.; Bernardi, Fabiano

doi:10.1016/j.apsusc.2020.146860

Cited by 47 publications

(27 citation statements)

References 38 publications

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“…The lattice constant values of plain CeO 2 and g-CeO 2– x microspheres were determined as 5.421 and 5.416 Å, respectively. , These values are also close to those calculated for ceria nanoparticles or porous, reduced ceria nanoparticles. , …”

Section: Resultssupporting

confidence: 79%

“…Based on the calculated crystallite size values, the average crystallite size values of plain CeO 2 and g-CeO 2– x microspheres were calculated as 12.4 and 11.8 nm, respectively. These values are close or slightly higher with respect to those reported for ceria nanoparticles. − …”

Section: Resultssupporting

confidence: 78%

“…41,44 These values are also close to those calculated for ceria nanoparticles or porous, reduced ceria nanoparticles. 41,43 Survey X-ray photoelectron spectra (XPS) of plain CeO 2 and g-CeO 2−x microspheres are given in Figure 3A. The surface atomic compositions of both types of microspheres calculated based on XPS spectra are given in Table 2.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…42,43,45,46 Therefore, atomic fraction of Ce(III) can be calculated as a weight ratio of the integral area (A x , x = u, u″, u‴, v, v″, v‴, u o , u′, v o , v′) under their respective Ce(III) and Ce(IV) components as given by eq 3. 42,43,45,46…”

Section: ■ Results and Discussionmentioning

confidence: 99%

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Porous, Oxygen Vacancy Enhanced CeO_2–x Microspheres with Efficient Enzyme-Mimetic and Photothermal Properties

Akdoğan

Gökçal

Polat

et al. 2022

ACS Sustainable Chem. Eng.

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Porous, defective, gray cerium oxide (g-CeO2–x ) microspheres 4.8 μm in size were synthesized as a multifunctional nanozyme with catalase-, peroxidase-, and oxidase-like activities by the reduction of monodisperse-porous cerium oxide (CeO2) microspheres. Higher Ce(III) atomic fraction, more oxygen vacancy, and lower oxygen content on the surface of g-CeO2–x microspheres were shown by Raman and X-ray photoelectron spectroscopy. Band gap energies of plain CeO2 and g-CeO2–x microspheres were determined as 3.0 and 2.4 eV, respectively. Reactive oxygen species (ROS) related to the enzyme-mimetic activity of g-CeO2–x microspheres were determined as singlet oxygen (1O2•) and superoxide anion (•O2 –) by ESR spectroscopy. Michaelis–Menten plots sketched for catalase-, peroxidase-, and oxidase-like activities provided superior maximum substrate consumption rates for g-CeO2–x microspheres. Oxidase- and peroxidase-like activities were used for developing colorimetric and fluorometric protocols for the detection of nitrite as a common pollutant, respectively. g-CeO2–x microspheres also exhibited a photothermal response explained by enhanced light adsorption originated from more oxygen vacancies. A temperature elevation up to 19 °C was obtained under near infrared laser irradiation at 808 nm. Photothermal response accompanying with multifunctional enzyme-mimetic activities makes the porous nanozyme a promising synergistic therapy agent capable of overcoming hypoxia and generating additional ROS in a tumor microenvironment.

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Section: Resultssupporting

confidence: 79%

Section: Resultssupporting

confidence: 78%

Section: ■ Results and Discussionmentioning

confidence: 99%

Section: ■ Results and Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Porous, Oxygen Vacancy Enhanced CeO_2–x Microspheres with Efficient Enzyme-Mimetic and Photothermal Properties

Akdoğan

Gökçal

Polat

et al. 2022

ACS Sustainable Chem. Eng.

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“…27 However, after interaction with TEP, Ce4T 5 and Ce4T 6 samples exhibited a broad absorbance peak with a significant portion tailing in the visible region of the spectra, suggesting that the interaction results in changes in the band structure of the CeNPs, thus causing a significant red shift. 71,72 The presence of surface oxygen defects on CeNPs has been linked to the redshift, suggesting that TEP increases the surface oxygen defects and consequently the surface Ce 3+ concentration. Further, the interaction of CeNPs (3+) with TEP was studied by PL spectroscopy.…”

Section: Resultsmentioning

confidence: 99%

Tuning the enzyme-like activities of cerium oxide nanoparticles using a triethyl phosphite ligand

et al. 2022

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Cyclic Voltammetry Study and Solar Light Assisted Photocatalytic Activity of the CeFeO₃/CeO₂/Fe₂O₃ Composite

Kanimozhi,

Harikrishnan,

Mani

et al. 2024

Luminescence

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The semiconducting nature of CeFeO3/CeO2/Fe2O3 nanocomposite has permitted the degradation of the organic toxic dye methylene blue under the irradiation of ultraviolet and visible light portions of solar radiation. Fullprof‐assisted Rietveld refinement analysis, performed using the Match software, has revealed the orthorhombic nature of CeFeO3. In addition, in the synthesized material, the cubic phase byproduct CeO2 was found due to the highly oxidizing nature of the cerium element. This occurred due to 6 min microwave irradiation because the microwave‐assisted technique offered random distribution of heating during the supply of 800‐W power for 30 s, followed by 12 cycles. Additionally, the presence of Fe2O3 was also confirmed through Match software‐assisted Rietveld refinement analysis through phase matching. During the synthesis, a certain portion of the synthesized CeFeO3 experienced overheating, leading to phase transformation from CeFeO3 into Fe2O3 and CeO2. The unit cell compositions of CeFeO3, CeO2, and Fe2O3 were found in the sample material with 35.54%, 52.43%, and 12.03%, respectively. The appearance of a fingerprint absorption region in the FTIR spectrum around 577.36 and 535.38 cm−1 further confirmed the similarity of these values (577.36 and 535.38 cm−1) to those obtained from the calculated values obtained by substituting Rietveld refined bond length parameters. The fourth step process in the thermal analysis curve (TGA) revealed the oxidation process, which led to the destruction of the CeFeO3 phase, causing the transformation of CeFeO3 into two byproducts (CeO2 and Fe2O3). This oxidation process permitted in an observable weight gain, which is observed in the thermal analysis curve (TGA). A cyclic voltammetry study (the experimentally measured current–voltage characteristic curve) revealed slightly distorted semirectangular CV curves, confirming the pseudo‐capacitive behavior of the synthesized composite.

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Shifting the band gap from UV to visible region in cerium oxide nanoparticles

Cited by 47 publications

References 38 publications

Porous, Oxygen Vacancy Enhanced CeO_2–x Microspheres with Efficient Enzyme-Mimetic and Photothermal Properties

Porous, Oxygen Vacancy Enhanced CeO_2–x Microspheres with Efficient Enzyme-Mimetic and Photothermal Properties

Tuning the enzyme-like activities of cerium oxide nanoparticles using a triethyl phosphite ligand

Cyclic Voltammetry Study and Solar Light Assisted Photocatalytic Activity of the CeFeO₃/CeO₂/Fe₂O₃ Composite

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Shifting the band gap from UV to visible region in cerium oxide nanoparticles

Cited by 47 publications

References 38 publications

Porous, Oxygen Vacancy Enhanced CeO2–x Microspheres with Efficient Enzyme-Mimetic and Photothermal Properties

Porous, Oxygen Vacancy Enhanced CeO2–x Microspheres with Efficient Enzyme-Mimetic and Photothermal Properties

Tuning the enzyme-like activities of cerium oxide nanoparticles using a triethyl phosphite ligand

Cyclic Voltammetry Study and Solar Light Assisted Photocatalytic Activity of the CeFeO3/CeO2/Fe2O3 Composite

Contact Info

Product

Resources

About

Porous, Oxygen Vacancy Enhanced CeO_2–x Microspheres with Efficient Enzyme-Mimetic and Photothermal Properties

Porous, Oxygen Vacancy Enhanced CeO_2–x Microspheres with Efficient Enzyme-Mimetic and Photothermal Properties

Cyclic Voltammetry Study and Solar Light Assisted Photocatalytic Activity of the CeFeO₃/CeO₂/Fe₂O₃ Composite