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Self-generating CeVO4 as conductive channel within CeO2/CeVO4/V2O5 to induce Z-scheme-charge-transfer driven photocatalytic degradation coupled with hydrogen production
摘要： The construction of highly efficient Z-scheme photocatalytic system is regarded as a hot research topic in the fields of environmental remediation and renewable energy production. In this work, a novel Z-scheme CeO2/CeVO4/V2O5 photocatalyst is successfully prepared by using solid phase reaction method. The photocatalytic degradation of organic pollutant (Methylene Blue) with simultaneous hydrogen production is efficiently realized over the prepared Z-scheme CeO2/CeVO4/V2O5 photocatalysts under visible-light irradiation. The effects of treatment temperatures and treatment times of CeO2/V2O5 composite on the photocatalytic performance of Z-scheme CeO2/CeVO4/V2O5 photocatalyst are studied. The as-prepared Z-scheme CeO2/CeVO4/V2O5 (550-3) photocatalyst heat-treated at 550 °C for 3.0 h exhibits the highest photocatalytic performance. It can be ascribed to a moderate amount of CeVO4 nanoparticles generated between CeO2 and V2O5. The generated CeVO4 nanoparticles can be used as effective conductive channel to transfer the photo-generated carriers. At the same time, as redox reaction centers it can further accelerate the transfer of photo-generated electrons, effectively enhancing the separation efficiency of photo-generated electron and hole pairs. Furthermore, cyclic test demonstrates that the as-prepared Z-scheme CeO2/CeVO4/V2O5 (550-3) photocatalyst still maintains a high level of photocatalytic activity within five periods under the same conditions. Moreover, the related photocatalytic mechanism for degradation of organic pollutants with simultaneous hydrogen evolution over the Z-scheme CeO2/CeVO4/V2O5 (550-3) photocatalyst is proposed. Perhaps, this study affords a simple and novel method to design and develop next generation of highly efficient Z-scheme photocatalysts.
关键词： Conductive channel,Z-scheme CeO2/CeVO4/V2O5 photocatalyst,Solid phase reaction method,Simultaneous hydrogen evolution,Visible-light photocatalytic degradation
更新于2025-11-19 16:51:07
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Multi-layer CeO2-wrapped Ag2S microspheres with enhanced peroxidase-like activity for sensitive detection of dopamine
摘要： A novel core-shell structure Ag2S@CeO2 microspheres were synthesized by growing multi-layer CeO2 onto Ag2S particles. Compared with pure Ag2S, the resultant composite catalyst exhibited highly improved peroxidase-like activity. Influences of pH, temperature, H2O2 concentration and the amount of catalyst on the catalytic activity of Ag2S@CeO2 were investigated. Besides, Ag2S@CeO2 displayed a strong affinity towards H2O2 and 3,3',5,5'-tetramethylbenzidine (TMB). Based on the excellent peroxidase-like activity of Ag2S@CeO2 microspheres, a highly sensitive and selectivity colorimetric method for dopamine detection was developed. The possible catalytic mechanism was also studied using fluorescent probe analysis. It is believed that the efficient biosensor based on the as-prepared Ag2S@CeO2 microspheres can apply for biological analysis and environmental monitoring.
关键词： Core-shell,Ag2S,CeO2,Peroxidase,Dopamine
更新于2025-11-14 17:15:25
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Structure and photocatalytic oxidation desulfurization performance of CeO2/HTi2NbO7-NS nanocomposite
摘要： CeO2/HTi2NbO7-NS nanocomposite based on HTi2NbO7 nanosheet (HTi2NbO7-NS) and Cerium dioxide nanoparticles (CeO2-NPs) was fabricated through an exfoliation-restructuring method. The as-prepared samples were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), laser Raman Spectroscopy (LRS), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflection spectroscopy (UV-Vis DRS) and N2 adsorption-desorption measurements. The adsorption and photocatalytic properties of the as-prepared samples were evaluated using ethyl mercaptan (EM) in methane gas as the model pollutant. The results indicated that CeO2-NPs were uniformly distributed on the surface of HTi2NbO7-NS and the band gap energy of CeO2/HTi2NbO7-NS nanocomposite was reduced compared with its precursor. The type-Ⅱ heterojunction was formed due to suitable band structures of host and guest materials. The CeO2/HTi2NbO7-NS nanocomposite owns the best adsorption capacity and photocatalytic oxidation activity, which was mainly attributed to the lower band gap and efficient separation of electron-hole pairs of CeO2/HTi2NbO7-NS nanocomposite.
关键词： CeO2/HTi2NbO7-NS,ethyl mercaptan (EM),exfoliation-restructuring,photocatalytic oxidation,type-Ⅱ heterojunction
更新于2025-09-23 15:23:52
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Synthesis of g-C3N4/N-doped CeO2 composite for photocatalytic degradation of an herbicide
摘要： In photocatalysis, surface engineered CeO2 could be vital due to oxygen vacancies arise from multiple valency, i.e. Ce3+ and Ce4+. This study reports photocatalytic properties of g-C3N4/CeO2 composite synthesized by a facile method in the presence of l-arginine. Physicochemical properties of g-C3N4/CeO2 material were analyzed through various characterization techniques such as XRD, UV–Vis, physisorption, etc., and correlated with its photocatalytic activity. Observed bandgap of the synthesized composite material was in the visible region, around 2.8 eV which is less than that of typical ceria, but higher than bandgap of exfoliated g-C3N4. On the further side, N doping into CeO2 was confirmed through XPS analysis. It is estimated that synthesis method aided for the N doping, which further played key role in lowering the bandgap of g-C3N4/CeO2 composite. Finally, Photocatalytic activity of g-C3N4/CeO2 composite was analyzed through degradation of an herbicide i.e. diuron, and the study revealed the good performance of the catalyst.
关键词： Graphitic carbon nitride,Photocatalysis,N doping,Herbicide,CeO2
更新于2025-09-23 15:23:52
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Effects of Calcination Temperature on Morphology and Structure of CeO2 Nanofibers and their Photocatalytic Activity
摘要： Calcination temperature plays a critical role on morphology and structure of CeO2 nanofibers, thus affecting its photocatalytic activity. CeO2 nanofibers with diameter of 95 nm were successfully fabricated by electrospinning combining with calcination. The calcination temperature was determined by TGA results ranging from 500℃ to 800℃. The morphology and structure of samples obtained with different calcination temperatures, have been characterized by SEM and XRD. Meanwhile, the specific surface area of samples were checked by BET, that was decreased 17 times from 56.3 m2/g to 3.3 m2/g, as the temperature increasing from 500℃ to 800℃. Normally, the higher specific surface area, the more efficiency photocatalytic activity. But it was interesting that the photodegradation rate of methylene blue was increased from 67% to 98% for CeO2 catalyst obtained at 500℃ and 800℃, with 4 times higher kinetic constant reaction rate under UV irradiation for 60 min. It demonstrates that the photocatalytic activity of CeO2 nanofibers catalyst is not directly related to the specific surface area, and increasing the calcination temperature has a positive effect for the photocatalytic efficiency.
关键词： Calcination,Porous Materials,Microstructure,CeO2 Nanofiber,Photocatalysis
更新于2025-09-23 15:23:52
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A critical review on visible-light-response CeO2-based photocatalysts with enhanced photooxidation of organic pollutants
摘要： Organic pollutants’ treatment in wastewater has attracted extensive attention due to its degradation-resistance and potentially hazardous to human health. Some organic matters such as persistent organic pollutants (POPs) could exist in environment and resist to decomposition, which may cause chronic intoxication or even cancers. Because photocatalytic technique is efficient, nontoxic, and cost-effective to degrade organic pollutants, some semiconductors including TiO2 and ZnO as photocatalysts have aroused wide public concern. CeO2 has been reported as an efficient photocatalyst in contrast to TiO2 owing to its high oxygen storage, eco-friendly properties and photostability. But inefficient utilization of solar energy due to its intrinsic wide bandgap restrains its further application in real environmental pollutant treatment. In order to improve photocatalytic performances of CeO2, some modifications have been developed such as doping ions, coupling with semiconductor and construction of CeO2-based solid-solution. The purpose of this review is to introduce these techniques, reveals its fundamental mechanisms and the recent researches about photodegradation of organic pollutants in wastewater over CeO2-based photocatalysts. Besides, this review will evaluate the photocatalytic performance for organic pollutants and outlook the challenges and prospects in the future.
关键词： Modification,CeO2,Visible-light-response,Photodegradation,Organic pollutants
更新于2025-09-23 15:21:21
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Microstructure and properties of CeO2-doped CoCrFeMnNi high entropy alloy fabricated by laser metal deposition
摘要： Rare earth elements are usually regarded as e?cient additives for property enhancement of many types of alloys. In the present study, the CoCrFeMnNi high entropy alloy (HEA) was doped with CeO2, and such composites were for the ?rst time obtained by the laser metal deposition (LMD) process. The microstructure, phase compositions, microhardness and crystallographic texture of the HEA/CeO2 composites were investigated. It was demonstrated that CoCrFeMnNi HEA/CeO2 samples were successfully obtained by the LMD process. Meanwhile, small irregular shape oxides rich in Mn and Cr were observed in the HEA/ CeO2 composite. Rare earth element Ce was found to be evenly distributed throughout the sample. Heterogeneous dendritic microstructure with a long columnar grains oriented along the build direction was observed. The measured average microhardness is 181.72 ± 9.72 HV0.1.
关键词： Composite,CeO2,High entropy alloy,Laser metal deposition,Additive manufacturing,CoCrFeMnNi
更新于2025-09-23 15:21:01
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Preparation and Characterization of CeO2-C60 Nanocomposites and Their Application to Photocatalytic Degradation of Organic Dyes
摘要： Cerium oxide nanoparticles were prepared by the reaction of cerium nitrate hexahydrate and sodium hydroxide. Cetyltrimethyl ammonium bromide (C19H42NBr) was added as a templating agent. The yellow precipitate obtained by the reaction was calcined with fullerene (C60) for 2 h at 700 °C in an electric furnace to synthesize CeO2-C60 nanocomposites. The synthesized samples were characterized by X-ray diffraction, scanning electron microscopy. The photocatalytic activity of the CeO2-C60 nanocomposites for the degradation of organic dyes such as methylene blue, brilliant green, rhodamine B and methyl orange upon irradiation with 254 nm UV light was investigated using a UV-visible spectrophotometer.
关键词： Organic dyes,Photocatalytic activity,Degradation,CeO2-C60 nanocomposites,UV irradiation
更新于2025-09-23 15:21:01
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Oxygen Vacancies-Enhanced CeO2:Gd Nanoparticles for Sensing Tumor Vascular Microenvironment by Magnetic Resonance Imaging
摘要： The specific characteristics of the tumor vascular microenvironment such as microvascular permeability and water diffusion have been demonstrated to play essential roles in the evaluation of infiltration of tumors. However, at present, there are few contrast agents (CAs) for magnetic resonance imaging (MRI) to enhance the sensitivity to acquire this vital information. Herein, we develop Gd doped (CeO2:Gd) nanoparticles as CA to detect the tumor vascular microenvironment with high sensitivity. The lattice oxygen vacancies on the surface of CeO2:Gd nanoparticles could bind considerable water molecules to improve the r1 value, achieving an excellent dynamic contrast-enhanced perfusion weighted imaging (DCE-PWI) performance for the measurement of microvascular permeability. The water molecules’ diffusion limited by oxygen vacancies of CeO2:Gd nanoparticles further enhance the diffusion-weighted magnetic resonance imaging (DWI) signal in vitro and in vivo. Excitingly, the strategy is not only essential for obtaining tumor vascular microenvironment information but also offers a way for further research of how to design magnetic resonance CAs.
关键词： CeO2:Gd nanoparticles,oxygen vacancies,microvascular,tumor microenvironment,DWI/DCE-PWI
更新于2025-09-23 15:21:01
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Fabrication of raspberry-shaped reduced graphene oxide labelled Fe/CeO2 ternary heterojunction with an enhanced photocatalytic performance
摘要： Herein, we report a raspberry-shaped reduced graphene oxide labelled Fe-CeO2 ternary photocatalyst synthesized via simple hydrothermal method. In order to evaluate structural, morphological, elemental composition and optical properties, resultant photocatalysts were characterized by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), energy dispersive x-ray analysis (EDX), photoluminescence (PL) and UV–visible spectroscopy respectively. The photocatalytic efficiency of as-prepared ternary catalyst was investigated by the degradation of congo red dye (CR) in aqueous medium under UV light. The ternary Fe-CeO2/RGO nanocomposite show outstanding photocatalytic degradation performance. The co-ordination and synergistic effect between reduced graphene oxide sheets and redox system of the cerium (Ce4+/ Ce3+) along with iron (Fe3+/ Fe2+) are accountable for the excellent photocatalytic performance of Fe-CeO2/RGO nanocomposite. The reduced graphene oxide sheets and redox systems acts as a trapping sites for photogenerated electrons and thereby significantly reduced the recombination of charge carriers. Moreover, a good reusability and stability suggest that ternary material has a great ability in removal of organic pollutants. Further, this report may offer a new strategy to fabricate and design a material for energy and environmental remediation.
关键词： Raspberry-shaped Fe-CeO2/RGO nanocomposite,Congo red,Photocatalytic degradation
更新于2025-09-23 15:19:57