Colloid and Interface Science Communications
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2021
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IF 4.914
Xueqin Wang,Helong Xu,Xiaohang Luo,Ming Li,Man Dai,Qihui Chen,Hua Song
Herein, CeO 2 /TiO 2 heterostructures are synthesized adopt a simple and profitable sol-gel technique. The nanostructures comprised of ultrafine and well-distributed CeO 2 nanoparticles on the TiO 2 surface. The obtained catalysts were characterized via X-ray diffraction, nitrogen adsorption , Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy , photoluminescence spectroscopy, and ultraviolet (UV)-visible spectroscopy tests. The as-prepared heterostructures exhibited a visibly enhanced photodegradation performance using phenol(38 ppm) as the model of organic pollutants . The achieved degradation efficiency was 99.1% under UV-light irradiation for 120 min and the TOC removal was 81.31% when using CeO 2 /TiO 2 as catalyst with the CeO 2 loading of 0.5%. The enhanced property was ascribed to the formation of a heterojunction after coupling CeO 2 with TiO 2 , which could capture the phenol molecules and improve the adsorption properties of the materials. Meanwhile, the heterostructures inhibited photogenic carriers recombination, thereby extending the optical response range. Furthermore, the as-prepared catalysts possessed favorable cycle performances and were reutilized for four cycles with insignificantly reduced property, the degradation rate were decreased slightly to 94.0% with a inappreciable decline in Ce and Ti leaching, suggesting it's preeminent stability and recyclability in the process of photocatalytic .
研究领域:
环境科学
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材料科学
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DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
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2024
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IF 4
Zhengjiang Liu,Dan Zhou,Huiyan Ma,Lei Xing,Qiancheng Zhang,Juming Liu
SO 4 2− /CeO 2 /TiO 2 composite oxides are successfully fabricated via sol-gel method and impregnation process for photocatalytic H 2 production. The characterization results from XRD, FTIR and TEM revealed that the heterojunctions were formed by the formation of Ti-O-Ce bond across the SO 4 2− /CeO 2 /TiO 2 interface, which was contributed significantly to separation of photo-generated carriers. Py-FTIR spectra and XPS results indicated that Lewis acid and Brønsted acid sites were formed over the surface of SO 4 2− /CeO 2 /TiO 2 composite, which was owing to SO 4 2− coordinated to the metal on the sample surface. The induced Lewis acid sites could enhance the separation of photogenerated carriers, and Brønsted acid sites could provide protons for photocatalytic H 2 production. In addition, the Lewis acidity could facilitate the shift of conduction band minimum to a more negative value, which improves the photocatalytic H 2 production capacity of SO 4 2− /CeO 2 /TiO 2 . The results of photocatalytic H 2 production revealed that SO 4 2− /CeO 2 /TiO 2 composite exhibits superior photocatalytic activity compared to bare CeO 2 , TiO 2 and CeO 2 -TiO 2 composite. Notably, it achieves the average H 2 yield rate of 6295.2 μmol· g −1 h −1 over a period of 5 h. Combine the results of spectra analysis and photocatalytic activity H 2 evolution, it can be concluded that the synergetic effects of heterojunction structure of CeO 2 /TiO 2 composite and acid impregnation promoted the photocatalyst activity.
研究领域:
材料科学
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催化化学
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DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
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2018
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IF 3.525
Lei Chen,Ding Weng,Jiadao Wang,Duan Weng,Li Cao
The CeO 2 -TiO 2 (CeTi) and CeO 2 /WO 3 -TiO 2 (CeWTi) catalysts were prepared by a sol-gel precipitation method and their NH 3 -NO/NO 2 selective catalytic reduction (SCR) performance was studied. N 2 O formation and effect of oxygen concentration on SCR performance over CeWTi catalyst were also investigated while varying the NO 2 /NO x ratio. Results indicate that fast SCR behavior of CeWTi catalyst has the best NH 3 -NO/NO 2 SCR performance due to the catalyst reoxidation rate by NO 2 higher than by O 2 . Compared with CeTi catalyst, CeWTi catalyst exhibits higher de-NO x performance under NH 3 -NO/NO 2 SCR conditions. As the CeTi and CeWTi catalysts exhibit similar redox property, addition of WO 3 provides more acid sites which accelerate the reaction between NH 4 NO 3 and NO to get a superior low-temperature activity. Amount of N 2 O formation shows a peak at 250 °C mainly derived from NH 4 NO 3 decomposition.
研究领域:
催化劑科學
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環境工程
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2018
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IF 3.794
Jinshuang Wang,Junbin Sun,Qiangshan Jing,Bing Liu,Hao Zhang,Yu Yongsheng,Jieyan Yuan,Shujuan Dong,Xin Zhou,Xueqiang Cao
The properties of ZrO 2 co-stabilized by CeO 2 and TiO 2 ceramic bulks were investigated for potential thermal barrier coating (TBC) applications. Results showed that the (Ce 0.15 Ti x )Zr 0.85-x O7 (x = 0.05, 0.10, 0.15) compositions with single tetragonal phase were more stable than the traditional 8YSZ at 1573 K. These compositions also showed a large thermal expansion coefficient (TEC) and a high fracture toughness, which were comparable to those of YSZ. However, the phase stability, fracture toughness and sintering resistance of the CeO 2 -TiO 2 -ZrO 2 system showed a decline tendency with the increase of TiO 2 content. The TEC of the ceramic bulks decreased with increase of TiO 2 content as well because the crystal energy was enhanced with increasing substitution of Zr 4+ by smaller Ti 4+ . The (Ce 0.15 Ti 0.05 )Zr 0.8 O 2 had the best comprehensive properties among the (Ce 0.15 Ti x )Zr 0.85-x O 2 compositions as well as a low thermal conductivity . Therefore, it can be explored as a TBC candidate material for high-temperature applications.
研究领域:
材料科学
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热力学工程
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DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2018
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IF 4.521
Li Cao,Lei Chen,Xiaodong Wu,Rui Ran,Tengfei Xu,Ze Chen,Duan Weng
The CeO 2 /TiO 2 catalyst was prepared by a deposition-precipitation method, which exhibited high low-temperature activity under the fast SCR condition. By using transient reaction analysis (TRA), the steps in the fast SCR, including NO 2 adsorption and decomposition, reaction between nitrates and NO, ammonium nitrate formation and reduction by NO, were investigated. Diffuses reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments, via NO + O 2 or NO + NO 2 adsorption, ammonium species reaction with NO x and NO reaction with NH 4 NO 3 , were designed to identify the roles of NO, NO 2 and NH 3 in fast SCR. Based on L-H mechanism, the NH 4 NO 3 formation played an important role in low-temperature SCR reaction. Compared with the behavior in standard SCR, the higher activity in the presence of NO 2 was ascribed to the faster NH 4 NO 3 formation rate and larger amounts of nitrates/nitrites. This phenomenon provided a basis for developing Ce-based catalysts as SCR catalysts for diesel exhaust aftertreatment.
研究领域:
催化化学
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环境科学
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产品关联
DOI
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2024
·
IF 4.2
Zhihua Zhao,Shixin Ma,Abu Bakker Md Rahmatullah,Zhuo Chen,Yafang Pan,Lan Wu,Bo Huang
The generation of high levels of ammonia in industries, agricultural sectors, and water treatment plants has triggered the necessity to detect high ammonia concentrations in a flexible way to ensure proactive measures for protecting humans and the environment. Therefore, it is essential to develop highly sensitive multifunctional sensors that have long-term stability, high durability, and a large stretch range. In our work, a novel approach was developed for fabricating flexible sensors consisting of polyurethane (PU) yarn and the loaded Ti 3 C 2 T x /CeO 2 /TiO 2 (abbreviated as MTCe) nanocomposites. The structures and morphology of the yarn-shaped sensors were analysed using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and other characterisation methods. In addition, gas and strain responses were recorded and analysed using an AES-4SD flexible electronic device. The response of the yarn-shaped sensors to 100 ppm NH 3 was 42.9 % at room temperature (25 °C), indicating its excellent gas sensitivity. In addition, the sensors exhibited some key advantages, such as a large stretch range (60 %), high sensitivity (up to 385.285), and good durability (200 stretches/releases at 20 % stretch), which may be considered a remarkable achievement in the field of flexible sensor manufacturing for multiple applications.
研究领域:
材料科学
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环境科学
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传感器技术
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xukang Han,Yuanhang Zhang,Jinhu Hu,Jiao Liu,Mingliang Ma,Yuhao Feng,Xiyao Wang,Guoxu Sun,Wei Gao,Yonglei Chi,Zihan Guo
With the advancement of wireless communication and electronic equipment , microwave absorption materials (MAMs) have more and more broad applications in related fields. Ti 3 C 2 T x -MXene with unique two-dimensional structure and excellent dielectric properties is often used as a precursor of nano-TiO 2 , which is a potential MAMs. Carbon nanofibers , as a one-dimensional material, have great electrical conductivity and can form interconnected three-dimensional conductive networks. In this study, Ti 3 C 2 T x -MXene was prepared by in-situ HF etching method, and further combined with the benefits of Co, Ce metals, and carbon nanofibers. Co/CeO 2 /TiO 2 /CNFs were prepared via a facile technique for electromagnetic microwave (EM) absorption, exhibiting excellent EM absorption performance due to the synergistic effects of dielectric and magnetic properties . The minimum reflection loss (RL min ) and effective absorption bandwidth (EAB) reache −63.35 dB (11.2 GHz) and 3.6 GHz (9.5–13.1 GHz), with a thickness of only 2.35 mm and a filling rate of 30 wt%, while the maximum EAB reaches 5.4 GHz (12.4–17.8 GHz) with a thickness of 1.82 mm, covering nearly the entire Ku band. By offering a novel strategy to the creation of brand-new, high-performance MAMs based on 1D carbon nanofibers with dielectric/magnetic synergy, this work is believed to support the development of upcoming MAMs.
研究领域:
材料科学
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电磁学
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2021
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IF 3.764
Wuyuan Liu,Zihan Gao,Xiangyun Zhao,Jiajian Gao,Runnong Yang,Lin Yu
The Cr-doped CeO2–TiO2 catalysts (CrCeTi) were produced via a coprecipitation method and used for selective catalytic reduction (SCR). The CrCeTi catalyst has good catalytic performance and sulfur resistance. The results of X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), NH3-TPD, NO-TPD, X-ray photoelectron spectroscopy (XPS), and H2 temperature-programmed reduction (H2-TPR) suggested that the CrCeTi catalyst with high specific surface area (SSA), strong surface acidity, enhanced redox properties, and effective electron transfer (3Ce4+ + Cr3+ ↔ 3Ce3+ + Cr6+) were the important promotion factors for excellent SCR properties. The in situ diffuse reflectance infrared spectroscopy (DRIFTS) indicated that the incorporation of Cr could improve the adsorption capacity of nitrate and the activation capacity of NH3, which were conducive to enhancing the catalytic activity. The thermogravimetric analysis-mass spectrometry (TG-MS) confirmed that the doping of Cr reduced SO2 surface adsorption and promoted the decomposition of NH4HSO4 (ABS). Therefore, the CrCeTi catalyst showed excellent resistance to SO2 poisoning.
研究领域:
环境科学
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催化化学
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2019
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IF 4.175
Xiaowang Lu,Xiazhang Li,Feng Chen,Zhigang Chen,Junchao Qian,Qinfang Zhang
The novel nitrogen doped two-dimensional CeO 2 –TiO 2 nanosheets with a thickness of less than 5 nm were synthesized by a facile impregnation method using Chinese rose petals as biological templates. The detailed characterization by field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) exhibited that the CeO 2 –TiO 2 composites exactly duplicated the microstructure of Chinese rose petal and the self-owned nitrogen was successfully doped into the CeO 2 –TiO 2 composites, which could enhance the visible light absorption efficiency. UV–Vis diffuse reflection spectroscopy (DRS), photocurrent measurement (PM), electrochemical impedance spectroscopy(EIS) and photoluminescence spectroscopy (PL) were used to analyze the electrons and holes separation efficiency, which revealed that CeO 2 and TiO 2 formed well-defined hetero junctions promoting the effective separation of photogenerated electrons and holes. The photocatalytic activity of the samples was evaluated by photocatalytic degradation of dibenzothiophene (DBT) in model oil. The amount of hydrogenperoxide (H 2 O 2 ) and photocatalysts , the molar ratios of Ce and Ti in CeO 2 –TiO 2 composites as photocatalytic reaction conditions were investigated. Results showed that the removal rate of DBT could reach 93.7% under visible light irritation for 3 h, when the molar ratio of Ce/Ti was 1/1, the mass ratio of photocatalyst/DBT was 1/2 and the molar ratio of H 2 O 2 /DBT was 2/1. The trapping experiments confirmed that the photoinduced active species (•OH radical) was responsible for the degradation of DBT. Further studies demonstrated that DBT was converted to the corresponding sulfone, which could be extracted by the polar solvent. Moreover, a plausible mechanism for the photocatalytic oxidative desulfurization of this nanocomposite was proposed.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2022
·Vol. 12
·期 4
·1245-1256
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IF 6.177
Jie Yang,Shan Ren,Mingming Wang,Zhichao Chen,Lin Chen,Lian Liu
Ce–Ti catalysts were considered as a promising replacement for V–Ti based catalysts for selective catalytic reduction (SCR) of nitrogen oxides (NO and NO2) with NH3. In this work, a CeO2/TiO2 catalyst was prepared by the impregnation method and studied by a series of in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments. The results showed that CeO2 particles grew along TiO2 faces and amorphous cerium in the lattice of TiO2, both of which are present on the CeO2/TiO2 catalyst. NH4+ might adsorb on the Ti–O–Ce structures or TiO2–CeO2 interface as Brønsted acid sites, while two types of NH4+ species were distinguished by the time-resolved spectroscopic method due to the different increasing trends. Based on the temporal evolution transient in situ DRIFTS spectra, L-NH3 had higher activity than coordinated NH3 species, which suggested that gas phase NO reacted preferentially with L-NH3. The NH4NO3 intermediate dominated the SCR reactions over the CeO2/TiO2 catalyst, which followed the Eley–Rideal mechanism.
研究领域:
催化化学
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环境科学
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
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2022
·
IF 5.532
Zhijian Wang,Lanlan Liu,Qifeng Du,RuiTao Tang,Jun Ai,Ying Chen
Ti-related oxide ceramics often exhibit excellent microwave dielectric properties and are widely applied in the microwave communication field. However, their microwave dielectric properties are often influenced by unstable defects, which are caused by the relatively low oxygen partial pressure at high sintering temperatures . In this work, Al 2 O 3 was introduced to improve the defect structures of the 0.85CeO 2 -0.15TiO 2 ceramics. According to the XPS pattern and AC conductivity analysis, Al 2 O 3 doping could stabilize the valence state of Ti but increase the oxygen vacancy concentration. Q × f first increased and then decreased as the Al 2 O 3 content increased. The highest Q × f value of 54361 GHz was obtained for the CTA0.015 sample sintered at 1275 °C, as well as the ε r of 29.41 and τ f of +7.8 ppm/°C. Finally, the CTA0.015 sample was used to prepare a microstrip antenna via the screen-printing process, which exhibited a good temperature-independent resonant frequency and indicated good application prospects.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Wen Luo,Jing Rong,Wanxia Zhao,Keke Kang,Lulu Long,Xiaojiang Yao
CeO 2 –TiO 2 catalysts with four different morphologies were successfully synthesized by a hydrothermal method and tested for selective catalytic reduction of NO x with NH 3 (NH 3 –SCR). For the four catalysts, CeO 2 –TiO 2 nanocubes (CT–NC) and nanorods (CT–NR) preferentially exposed {1 0 0} and {1 1 0} facets, respectively; furthermore, nanosheets (CT–NS) and nanospheres (CT–NH) mainly exposed {1 1 1} facet. Interestingly, CT–NH catalyst showed the best NH 3 –SCR performance and the NO x conversion exceeded 97% at 325 °C. Through a series of characteristic methods manifested that the short–range ordered structure of Ce–O–Ti in CT–NH catalyst provided stronger surface acidic sites to promote the high–temperature activity. Moreover, the abundant Ce 3+ species and appropriate reduction ability on {1 1 1} facet of CT–NH catalyst also caused outstanding de NO x activity. Reaction mechanism study showed that the Langmuir–Hinshelwood (L–H) mechanism and Eley–Rideal (E–R) mechanism existed simultaneously on all catalysts in NH 3 –SCR reaction. Meaningfully, two types of E–R mechanism were present on CT–NH catalyst, while L–H mechanism was dominant.
研究领域:
催化化学
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环境科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）