Journal of the American Chemical Society
·
2024
·
IF 14.4
Hao Yu,Yujin Ji,Chenchen Li,Wenxiang Zhu,Yue Wang,Zhiwei Hu,Jing Zhou,Chih-Wen Pao,Wei-Hsiang Huang,Youyong Li,Xiaoqing Huang,Qi Shao
A strain engineering strategy is crucial for designing a high-performance catalyst. However, how to control the strain in metastable phase two-dimensional (2D) materials is technically challenging due to their nanoscale sizes. Here, we report that cerium dioxide (CeO2) is an ideal loading material for tuning the in-plane strain in 2D metastable 1T-phase IrO2 (1T-IrO2) via an in situ growth method. Surprisingly, 5% CeO2 loaded 1T-IrO2 with 8% compressive strain achieves an overpotential of 194 mV at 10 mA cm–2 in a three-electrode system. It also retained a high current density of 900 mA cm–2 at a cell voltage of 1.8 V for a 400 h stability test in the proton-exchange membrane device. More importantly, the Fourier transform infrared measurements and density functional theory calculation reveal that the CeO2 induced strained 1T-IrO2 directly undergo the *O–*O radical coupling mechanism for O2 generation, totally different from the traditional adsorbate evolution mechanism in pure 1T-IrO2. These findings illustrate the important role of strain engineering in paving up an optimal catalytic pathway in order to achieve robust electrochemical performance.
研究领域:
材料科学
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电化学
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催化科学
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DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Mengjie Lu,Min Liu,Yaxin Wei,Huihui Xie,Wenbo Fan,Junzi Huang,Jindou Hu,Peng Wei,Weidong Zhang,Yahong Xie,Ying Qi
Cerium dioxide (CeO 2 ) semiconductor has received wide attention in the field of energy and environment due to its excellent oxygen storage capacity and abundant oxygen vacancies (OVs). Previous research demonstrated that the morphology and structure of the crystal had great influence on the physicochemical properties of the material. Herein, CeO 2 nanomaterials with different morphologies were prepared via a facile hydrothermal and template method. Systematic material characterizations suggested that the synthetic CeO 2 has different morphologies with CeO 2 nanorods (NRs), nanocubes (NCs), nanosheets (NSs), hollow spheres (HSs), and mesoporous CeO 2 (m-CeO 2 ), respectively. The visible-light-induced degradation performance of CeO 2 with different morphologies was investigated in aqueous solution using the antibiotic tetracycline (TC) as a model pollutant. The experimental results exhibited that the CeO 2 NRs possessed the best adsorption capacity and photocatalytic activity and more than 89.35% TC could be removed within 90 min. Combined with the XPS characterization results implied that the concentrations of Ce 3+ and OVs on the surface of CeO 2 with different morphologies were discrepancy, and the improved photocatalytic performance of CeO 2 NRs was mainly due to the higher concentration of Ce 3+ and OVs on the catalyst surface. These results confirmed that the regulation of the morphology of CeO 2 could effectively enhance its photocatalytic activity. Furthermore, the results of active species trapping experiments proved that the super oxide anion (•O 2 - ) radical and hole (h + ) played dominant roles in the degradation of TC.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
MOLECULES
·
2025
·Vol. 30
·期 5
·1161
·
IF 4.6
Jia Fang,Kejian Wang,Peng Chen,Xilong Xu,Chengzhuang Zhang,Yi Wu,Yan Yan,Zinong Zuo
In this study, a series of cerium dioxide catalysts with varying hydrothermal temperatures and times were synthesized using the hydrothermal method, without the use of templates. The impact of varying hydrothermal conditions on the activity of cerium dioxide catalysts was investigated through experiments to examine their oxidation characteristics in soot combustion. Among the conditions tested, the hydrothermal conditions of 140 °C and 6 h yielded the most optimal catalytic oxidation of soot, with a combustion characteristic temperature ( T p ) of 552 °C and a reduction of 122.9 °C. The integrated combustion index ( S ) and combustion stability coefficient ( R w ) were found to be 27.97 × 10 8 % 2 min −2 °C −3 and 90.76 × 10 5 , respectively. The indices of S and R w exhibited an improvement of 51.1% and 36.93%, respectively.
研究领域:
材料科学
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环境科学
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DOI
PubMed
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2021
·Vol. 168
·期 1
·010536
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IF 4.316
Huan Kang,Liming Xu,Yue Cai,Yao He,Jingkun Xu,Weiqiang Zhou
Binder-free and flexible oxygen-vacancy CeO2@C core–shell nanocomposites directly anchored on carbon cloth (CC) are prepared via a simple two-step process, in which CeO2 nanoparticles are hydrothermally fabricated and mixed with polyvinylpyrrolidone (PVP) composites, subsequently, as-formed CeO2@PVP composites coated on CC are calcined at 700 °C. The morphologies, structures and electrochemical properties of as-obtained CeO2@C nanocomposites are studied by SEM, HRTEM, XRD, XPS and electrochemical techniques, respectively. The CeO2@C nanocomposites are composed of the CeO2 core with diameter of about 10 nm and the carbon shell with thickness of about 1.5 nm. The electrochemical results reveal that the CeO2@C nanocomposites show a wide electrochemical active window of −1.0 ∼ 0.8 V and a specific capacitance of 141.56 F g−1 at 1 A g−1 in 1.0 M Na2SO4 electrolyte. In addition, an asymmetric supercapacitor (ASC) assembled with CeO2@C and poly(3,4-ethylene dioxythiophene) (PEDOT) can work in the wide operational voltage region of 2.0 V and deliver the energy density of 11.12 Wh kg−1 at 2000 W kg−1. The present study indicates that the CeO2@C will have a greater advantage in terms of energy density for CeO2 and its carbon-based composites supercapacitor electrodes.
研究领域:
材料科学
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电化学
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DOI
高影响因子
CHEMOSPHERE
·
2022
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IF 8.943
Ying Zhang,Liming Zhang,Jichang Lu,Wei Liao,Jin Zhang,Xiaoya Gao,Yongming Luo,Wenjie Zhu
Spherical cerium dioxide (CeO 2 –S) nanoparticles were successfully prepared using a solvothermal method, and their performances in catalytic oxidation reactions were studied. The CeO 2 –S catalyst showed superior low-temperature catalytic activity for styrene removal (T 90 = 118 °C, GHSV = 18,000 h −1 ) compared with commercial CeO 2 . The characterization results showed that there were numerous oxygen defects in CeO 2 –S that were key to its catalytic performance at low temperatures, high redox properties, and high adsorption capacity for the reaction gases (O 2 and styrene). Moreover, the catalytic performance of CeO 2 –S was highly stable (132 h), and the particles were reusable. FTIR and in-situ DRIFTS results showed that the type of intermediates formed during the oxidation of styrene determined the CeO 2 catalytic stability, and the main intermediates were bidentate carbonate species that accumulated on the surface of deactivated CeO 2 –S and were not thermally stable. Moreover, the soft carbon that also deposited on CeO 2 –S during the reaction was easily decomposed at higher temperatures. The role of the oxygen vacancies on the CeO 2 –S catalyst was further revealed by correlating the concentration of oxygen vacancies and the accumulation of coke on the catalyst surface.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
Frontiers in Materials
·
2021
·
IF 3.515
Pu Xingyu,Wang Chencheng,Chen Xingwang,Jin Jing,Li Wanfei,Chen Feng
The sol-gel method combined with the electrospinning technique were used to synthesize CeO2 nanofiber membranes and CeO2 fiber membranes doped with different contents of nano-silver. The thermal degradation behavior, phase structure, morphology, and optical and photocatalytic hydrogen production efficiency of CeO2 nanofiber membranes and CeO2 fiber membranes doped with different contents of nano-silver were studied. X-ray diffraction (XRD) results indicate that the increase of silver concentration can inhibit the formation of CeO2 crystal. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations show that in the prepared CeO2 with a diameter of about 100 nm and fiber membrane material doped with nano-silver, the fiber is made of a large number of accumulating grains. Analysis of optical properties found that the doped nano–silver CeO2 fiber membranes enhance the absorption of visible light and reduce the band gap of the material. Photocatalytic experiments show that the cerium dioxide nanofibers doped with nano-silver can greatly improve the photocatalytic performance of materials than that of pure CeO2. The Ag/CeO2 fiber membrane with the Ag/CeO2 molar ratio of 3:50 possesses the highest photocatalytic hydrogen production efficiency because of its high electron hole transfer and separation efficiency. This novel synthesis strategy can be used to prepare other broad band gap semiconductor oxides and enhance their photocatalytic activity.
研究领域:
材料科学
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环境科学
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能源科学
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2021
·
IF 5.316
Jie Pan,Shirui Wang,Ailian Chen,Yue Chen,Menghan Wang,Yang Chen
As one of the most significant rare-earth oxides, cerium dioxide (ceria, CeO 2 ) has an enormous potential in a variety of materials science applications due to many excellent characteristics. In this work, cubic-phase mesoporous CeO 2 (mCeO 2 ) nanospheres with nanocrystalline frameworks, high Ce 3+ and oxygen vacancy contents, large porosity and specific surface area, were fabricated via a facile solvothermal method using inorganic precursors and without surfactant as a template. The resulting products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV–vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy , photoluminescence (PL) spectroscopy, and N 2 adsorption-desorption analyses. Raman and XPS results confirmed the presence of Ce 4+ , Ce 3+ and Zr 4+ ions and oxygen vacancies. By comparison with the undoped ones, Zr-doping in mCeO 2 nanospheres contributed to increased concentrations of Ce 3+ (45.25% vs 32.64%) and oxygen vacancy (37.63% vs 27.53%), as well as decreased band gap energies (2.9 vs 3.1 eV). The photocatalytic activities of the pure and Zr-doped mCeO 2 nanospheres were evaluated with the degradation of methylene blue (MB) under visible-light irradiation. The Zr-doped mCeO 2 products exhibited a superior photodegradation rate of ca. 94% after 120 min visible-light illumination. A kinetic study suggested that the reaction followed pseudo-first order rate equation. The optimizations on Zr-doped mCeO 2 nanospheres against structural, optical, and physicochemical properties might be responsible for the enhanced visible-light-driven photocatalytic performance. The plausible photodegradation mechanism over MB dyes of mCeO 2 nanospheres were also proposed. This work is expected to provide an insight view into the design and synthesis of low-cost and high-efficiency CeO 2 -based photocatalysts with improved visible photocatalytic activity.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2021
·
IF 6.498
Hongliang Dai,Tongshuai Sun,Ting Han,Xiang Li,Zechong Guo,Xingang Wang,Yong Chen
Cerium dioxide nanoparticles (CeO 2 NPs) are ubiquitous in the water environment due to the extensive commercial applications. The complexity of heterogeneous humic acid (HA) plays a significant role in affecting the physicochemical properties of CeO 2 NPs in aqueous environments. However, the effects of light intensities and HA fractions on the interaction mechanism between CeO 2 NPs and HA are poorly understood. Here, we provided the evidence that both light intensities (>3 E L −1 s −1 ) and molecular weights (>10 kDa) can effectively affect the interactions between CeO 2 NPs and HA. The absolute content of reactive oxygen species (ROS) and quantum yield (Φ) of 3 HA* were inhibited when HA (10 mg of C L −1 ) interacts with CeO 2 NPs. However, they were positively correlated with the increasing irradiation time and simulated sunlight intensities. High molecular weights of HA fraction (>100 kDa) restrained the ROS generation and Φ of 3 HA* due to surface adsorption between HA and CeO 2 NPs blocking reactive sites, competitive absorption for simulated sunlight. Fourier transform infrared and three-dimensional excitation-emission matrix fluorescence spectroscopy confirmed that the carboxylic groups of HA have high complexation capacity with CeO 2 NPs. These findings are essential for us to improve the understanding of the impacts of HA on CeO 2 NPs under different conditions in natural waters.
研究领域:
环境科学
·
纳米生物学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Xinyu Chen,Diwei Shi,Min Bi,Jiexi Song,Yanqing Qin,Shiyu Du,Bianjing Sun,Chuntao Chen,Dongping Sun
Ensuring the consumption rate of noble metals while guaranteeing satisfactory hydrogen evolution reaction (HER) performance at different pH values is imperative to the development of Ru-based catalysts. Herein, we design a Mott-Schottky electrocatalyst (Ru/CeO 2 ) with a built-in electric field (BEF) based on density functional theory (DFT). The Ru/CeO 2 achieves the criterion current density of 10 mA cm −2 at overpotentials of 55 mV, 80 mV, and 120 mV in alkaline, acidic and neutral media, respectively. Both theoretical calculations and experimental analysis confirm that the improved HER activity in the Ru/CeO 2 catalyst could be due to the successful construction of BEF at the interface between the prepared Ru clusters and CeO 2 . Under the action of BEF, the electron-deficient Ru atoms can optimize the adsorption energy of H* and H 2 O and thus promote HER kinetics. Furthermore, the Ru/CeO 2 catalyst delivers a power density of approximately 94.5 mW cm −2 in alkaline-acidic Zn-H 2 O cell applications while maintaining good H 2 production stability. In this work, we optimize the electrocatalytic performance of the Ru/CeO 2 catalyst through examination of the interfacial BEF electrical charge, which combines hydrogen production with power generation and provides a promising method for sustainable energy conversion.
研究领域:
材料科学
·
电化学
·
理论计算
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2024
·Vol. 14
·期 18
·1498
·
IF 4.4
Penghui Lei,Xiaoyu Ji,Jie Qiu,Jiaxuan Si,Tao Peng,Changqing Teng,Lu Wu
Large-grained UO2is considered a potential accident-tolerant fuel (ATF) due to its superior fission gas retention capabilities. Irradiation experiments for cerium dioxide (CeO2), used as a surrogate fuel, is a common approach for evaluating the performance of UO2. In this work, spark plasma sintered CeO2pellets with varying grain sizes (145 nm, 353 nm, and 101 μm) and a relative density greater than 93.83% were irradiated with 4 MeV Xe ions at a fluence of 2 × 1015ions/cm2at room temperature, followed by annealing at 600 °C for 3 h. Microstructure, including dislocation loops and bubble morphology of the irradiated samples, has been characterized. The average size of dislocation loops increases with increasing grain size. Large-sized dislocation loops are absent near the grain boundary because the boundary absorbs surrounding defects and prevents the dislocation loops from coalescing and expanding. The distribution of bubbles within the grain is uniform, whereas the large-sized and irregularly shaped xenon bubbles observed in the small grain exhibit pipe diffusion along the grain boundaries. The bubble diameter in the large-grained pellet is the smallest. As the grain size increases, the volumetric swelling of the irradiated pellets decreases while the areal density of Xe bubbles increases. Elemental segregation, which tends to occur at dislocation loops and grain boundaries, has been analyzed. Large-grained CeO2pellet with lower-density grain boundaries exhibits better resistance to volumetric swelling and elemental segregation, suggesting that large-grained UO2pellets could serve as a potential ATF.
研究领域:
核材料科学
·
材料物理
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Shijun Zhang,Zesheng Zhang,Can Wang,Sikandar Khan,Lei Wang,Ruiyong Zhang,Xin Zhang,Jun Zhou,Jizhou Duan
For the first time, cerium dioxide CeO 2 nanoparticles with a foamy porous structure were prepared by green synthesis using coffee extract as a reducing and stabilising agent, and the porous CeO 2 photocatalysts were used for sterilisation. X-ray photoelectron spectroscopy (XPS) analysis confirmed the binding energies of the elements C1s, O1s, and Ce3d. Scanning electron microscope (SEM) and Transmission Electron Microscope (TEM)analysis revealed a highly porous and foam-like structure of CeO 2 . Ce−O stretching bands were observed by Fourier Transform Infrared Spectrometer (FT-IR) and Raman spectroscopy. The band gap of CeO 2 was estimated to be 3.24 eV by UV–Visible spectrum. Photocatalytic bactericidal efficacy of foam-structured CeO 2 was evaluated against bacteria. It was observed that CeO 2 exhibit a significant bactericidal effect against G + and G – bacteria as compared to spherical-structured CeO 2 prepared by conventional hydrothermal synthesis. The bactericidal characteristics and features of CeO 2 photocatalyst are attributed to the fact that the as synthesized porous structured promote the use of light and induces the enhanced production of reactive oxygen species (ROS), which in turn cause lipid peroxidation, membrane damage and ultimately kill bacteria.
研究领域:
材料科学
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环境科学
·
微生物学
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DOI
高影响因子
Materials Chemistry Frontiers
·
2024
·
IF 6
Jin Li,Wei Zhang,Xiujing Xing,Yaokang Lv,Renliang Lyu,Wei Xiong,Hao Li
Gold nanoparticles are extensively employed in the field of electrocatalytic nitrite reduction for ammonia synthesis, due to their exceptional conductivity and remarkable stability. However, the performance of a single metal is often limited and by combining different metals, the overall performance can be significantly improved to meet specific needs and application scenarios. The regulation of the interaction between loaded gold nanoparticles and metal oxide support materials represents an effective strategy for facilitating the reduction of nitrite to ammonia. In this work, we prepared three different structural morphologies of cerium dioxide (CeO2) – cubic (c-CeO2), rod-like (r-CeO2) and granular (p-CeO2), by modulating the hydrothermal temperature. The effect of the morphology of the CeO2 carriers on the surface structure of the composite catalyst, CeO2@Au, was systematically studied and its performance of the electrocatalytic reduction of ammonia from nitrite was explored. It was found that c-CeO2 loaded with Au nanoparticles possessed better electrocatalytic performance with an ammonia yield of 4007.9 μg h−1 mgcat−1 and a Faraday efficiency of 91.2% compared to r-CeO2 and p-CeO2. The results of the characterisation tests, conducted using scanning electron microscopy (SEM), elemental mapping analysis (EDS) and inductively coupled plasma (ICP), demonstrate that c-CeO2 exhibits enhanced crystallinity, a reduced particle size and a more uniform dispersion. Therefore, c-CeO2 is able to load more Au nanoparticles during the complexation process with Au, which in turn possesses more reactive active sites. In addition, the results of transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) showed that after the complexation of c-CeO2 with Au, some of the lattice fringes of c-CeO2 were distorted with defects leading to an increase in the content of oxygen vacancies, which greatly improved the active area of the catalyst. These physicochemical properties endow the c-CeO2@Au catalysts with excellent electrocatalytic nitrite-to-ammonia activity.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）